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Amen A, Yoo R, Fabra-García A, Bolscher J, Stone WJR, Bally I, Dergan-Dylon S, Kucharska I, de Jong RM, de Bruijni M, Bousema T, Richter King C, MacGill RS, Sauerwein RW, Julien JP, Poignard P, Jore MM. Target-agnostic identification of human antibodies to Plasmodium falciparum sexual forms reveals cross stage recognition of glutamate-rich repeats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.03.565335. [PMID: 37961136 PMCID: PMC10635103 DOI: 10.1101/2023.11.03.565335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Circulating sexual stages of Plasmodium falciparum (Pf) can be transmitted from humans to mosquitoes, thereby furthering the spread of malaria in the population. It is well established that antibodies (Abs) can efficiently block parasite transmission. In search for naturally acquired Ab targets on sexual stages, we established an efficient method for target-agnostic single B cell activation followed by high-throughput selection of human monoclonal antibodies (mAbs) reactive to sexual stages of Pf in the form of gamete and gametocyte extract. We isolated mAbs reactive against a range of Pf proteins including well-established targets Pfs48/45 and Pfs230. One mAb, B1E11K, was cross-reactive to various proteins containing glutamate-rich repetitive elements expressed at different stages of the parasite life cycle. A crystal structure of two B1E11K Fab domains in complex with its main antigen, RESA, expressed on asexual blood stages, showed binding of B1E11K to a repeating epitope motif in a head-to-head conformation engaging in affinity-matured homotypic interactions. Thus, this mode of recognition of Pf proteins, previously described only for PfCSP, extends to other repeats expressed across various stages. The findings augment our understanding of immune-pathogen interactions to repeating elements of the Plasmodium parasite proteome and underscore the potential of the novel mAb identification method used to provide new insights into the natural humoral immune response against Pf . Impact Statement A naturally acquired human monoclonal antibody recognizes proteins expressed at different stages of the Plasmodium falciparum lifecycle through affinity-matured homotypic interactions with glutamate-rich repeats.
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2
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Matos ADS, Soares IF, Rodrigues-da-Silva RN, Rodolphi CM, Albrecht L, Donassolo RA, Lopez-Camacho C, Ano Bom APD, Neves PCDC, Conte FDP, Pratt-Riccio LR, Daniel-Ribeiro CT, Totino PRR, Lima-Junior JDC. Immunogenicity of PvCyRPA, PvCelTOS and Pvs25 chimeric recombinant protein of Plasmodium vivax in murine model. Front Immunol 2024; 15:1392043. [PMID: 38962015 PMCID: PMC11219565 DOI: 10.3389/fimmu.2024.1392043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 06/03/2024] [Indexed: 07/05/2024] Open
Abstract
In the Americas, P. vivax is the predominant causative species of malaria, a debilitating and economically significant disease. Due to the complexity of the malaria parasite life cycle, a vaccine formulation with multiple antigens expressed in various parasite stages may represent an effective approach. Based on this, we previously designed and constructed a chimeric recombinant protein, PvRMC-1, composed by PvCyRPA, PvCelTOS, and Pvs25 epitopes. This chimeric protein was strongly recognized by naturally acquired antibodies from exposed population in the Brazilian Amazon. However, there was no investigation about the induced immune response of PvRMC-1. Therefore, in this work, we evaluated the immunogenicity of this chimeric antigen formulated in three distinct adjuvants: Stimune, AddaVax or Aluminum hydroxide (Al(OH)3) in BALB/c mice. Our results suggested that the chimeric protein PvRMC-1 were capable to generate humoral and cellular responses across all three formulations. Antibodies recognized full-length PvRMC-1 and linear B-cell epitopes from PvCyRPA, PvCelTOS, and Pvs25 individually. Moreover, mice's splenocytes were activated, producing IFN-γ in response to PvCelTOS and PvCyRPA peptide epitopes, affirming T-cell epitopes in the antigen. While aluminum hydroxide showed notable cellular response, Stimune and Addavax induced a more comprehensive immune response, encompassing both cellular and humoral components. Thus, our findings indicate that PvRMC-1 would be a promising multistage vaccine candidate that could advance to further preclinical studies.
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MESH Headings
- Animals
- Plasmodium vivax/immunology
- Plasmodium vivax/genetics
- Mice
- Antigens, Protozoan/immunology
- Antigens, Protozoan/genetics
- Malaria, Vivax/immunology
- Malaria, Vivax/prevention & control
- Antibodies, Protozoan/immunology
- Mice, Inbred BALB C
- Malaria Vaccines/immunology
- Female
- Protozoan Proteins/immunology
- Protozoan Proteins/genetics
- Epitopes, B-Lymphocyte/immunology
- Epitopes, B-Lymphocyte/genetics
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/genetics
- Disease Models, Animal
- Adjuvants, Immunologic
- Immunogenicity, Vaccine
- Antigens, Surface
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Affiliation(s)
- Ada da Silva Matos
- Immunoparasitology Laboratory, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil
| | - Isabela Ferreira Soares
- Immunoparasitology Laboratory, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil
| | | | | | - Letusa Albrecht
- Apicomplexa Research Laboratory, Carlos Chagas Institute, Curitiba, Brazil
| | | | - Cesar Lopez-Camacho
- Nuffield Department of Medicine, The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Ana Paula Dinis Ano Bom
- Immunological Technology Laboratory, Immunobiological Technology Institute (Bio-Manguinhos/Fiocruz), Rio de Janeiro, Brazil
| | | | - Fernando de Paiva Conte
- Eukaryotic Pilot Laboratory, Immunobiological Technology Institute (Bio-Manguinhos/Fiocruz), Rio de Janeiro, Brazil
| | | | | | | | - Josué da Costa Lima-Junior
- Immunoparasitology Laboratory, Oswaldo Cruz Institute (IOC), Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil
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3
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Salinas ND, Ma R, McAleese H, Ouahes T, Long CA, Miura K, Lambert LE, Tolia NH. A Self-Assembling Pfs230D1-Ferritin Nanoparticle Vaccine Has Potent and Durable Malaria Transmission-Reducing Activity. Vaccines (Basel) 2024; 12:546. [PMID: 38793797 PMCID: PMC11125772 DOI: 10.3390/vaccines12050546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/10/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024] Open
Abstract
Malaria is caused by eukaryotic protozoan parasites of the genus Plasmodium. There are 249 million new cases and 608,000 deaths annually, and new interventions are desperately needed. Malaria vaccines can be divided into three categories: liver stage, blood stage, or transmission-blocking vaccines. Transmission-blocking vaccines prevent the transmission of disease by the mosquito vector from one human to another. Pfs230 is one of the leading transmission-blocking vaccine antigens for malaria. Here, we describe the development of a 24-copy self-assembling nanoparticle vaccine comprising domain 1 of Pfs230 genetically fused to H. pylori ferritin. The single-component Pfs230D1-ferritin construct forms a stable and homogenous 24-copy nanoparticle with good production yields. The nanoparticle is highly immunogenic, as two low-dose vaccinations of New Zealand White rabbits elicited a potent and durable antibody response with high transmission-reducing activity when formulated in two distinct adjuvants suitable for translation to human use. This single-component 24-copy Pfs230D1-ferritin nanoparticle vaccine has the potential to improve production pipelines and the cost of manufacturing a potent and durable transmission-blocking vaccine for malaria control.
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Affiliation(s)
- Nichole D. Salinas
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA; (N.D.S.)
| | - Rui Ma
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA; (N.D.S.)
| | - Holly McAleese
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tarik Ouahes
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Lynn E. Lambert
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Niraj H. Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA; (N.D.S.)
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4
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Céspedes N, Donnelly EL, Hansten G, Fellows AM, Dobson M, Kaylor HL, Coles TA, Schauer J, Van de Water J, Luckhart S. Mast cell-derived IL-10 protects intestinal barrier integrity during malaria in mice and regulates parasite transmission to Anopheles stephensi with a female-biased immune response. Infect Immun 2024; 92:e0036023. [PMID: 38299826 PMCID: PMC10929420 DOI: 10.1128/iai.00360-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 01/11/2024] [Indexed: 02/02/2024] Open
Abstract
Malaria is strongly predisposed to bacteremia, which is associated with increased gastrointestinal permeability and a poor clinical prognosis. We previously identified mast cells (MCs) as mediators of intestinal permeability in malaria and described multiple cytokines that rise with parasitemia, including interleukin (IL)-10, which could protect the host from an inflammatory response and alter parasite transmission to Anopheles mosquitoes. Here, we used the Cre-loxP system and non-lethal Plasmodium yoelii yoelii 17XNL to study the roles of MC-derived IL-10 in malaria immunity and transmission. Our data suggest a sex-biased and local inflammatory response mediated by MC-derived IL-10, supported by early increased number and activation of MCs in females relative to males. Increased parasitemia in female MC IL-10 (-) mice was associated with increased ileal levels of chemokines and plasma myeloperoxidase (MPO). We also observed increased intestinal permeability in female and male MC IL-10 (-) mice relative to MC IL-10 (+) mice but no differences in blood bacterial 16S DNA levels. Transmission success of P. yoelii to A. stephensi was higher in female relative to male mice and from female and male MC IL-10 (-) mice relative to MC IL-10 (+) mice. These patterns were associated with increased plasma levels of pro-inflammatory cytokines in female MC IL-10 (-) mice and increased plasma levels of chemokines and markers of neutrophil activation in male MC IL-10 (-) mice. Overall, these data suggest that MC-derived IL-10 protects intestinal barrier integrity, regulates parasite transmission, and controls local and systemic host immune responses during malaria, with a female bias.
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Affiliation(s)
- Nora Céspedes
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, Idaho, USA
| | - Erinn L. Donnelly
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA
| | - Gretchen Hansten
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, Idaho, USA
| | - Abigail M. Fellows
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, Idaho, USA
| | - Megan Dobson
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, Idaho, USA
| | - Hannah L. Kaylor
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, Idaho, USA
| | - Taylor A. Coles
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, Idaho, USA
| | - Joseph Schauer
- Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, California, USA
| | - Judy Van de Water
- Division of Rheumatology, Allergy and Clinical Immunology, University of California, Davis, California, USA
| | - Shirley Luckhart
- Department of Entomology, Plant Pathology and Nematology, University of Idaho, Moscow, Idaho, USA
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA
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5
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Thongpoon S, Roobsoong W, Nguitragool W, Chotirat S, Tsuboi T, Takashima E, Cui L, Ishino T, Tachibana M, Miura K, Sattabongkot J. Naturally Acquired Transmission-Blocking Immunity Against Different Strains of Plasmodium vivax in a Malaria-Endemic Area in Thailand. J Infect Dis 2024; 229:567-575. [PMID: 37943633 PMCID: PMC10873188 DOI: 10.1093/infdis/jiad469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/30/2023] [Accepted: 11/04/2023] [Indexed: 11/12/2023] Open
Abstract
BACKGROUND Human immunity triggered by natural malaria infections impedes parasite transmission from humans to mosquitoes, leading to interest in transmission-blocking vaccines. However, immunity characteristics, especially strain specificity, remain largely unexplored. We investigated naturally acquired transmission-blocking immunity (TBI) against Plasmodium vivax, a major malaria parasite. METHODS Using the direct membrane-feeding assay, we assessed TBI in plasma samples and examined the role of antibodies by removing immunoglobulins through protein G/L adsorption before mosquito feeding. Strain specificity was evaluated by conducting a direct membrane-feeding assay with plasma exchange. RESULTS Blood samples from 47 patients with P vivax were evaluated, with 37 plasma samples successfully infecting mosquitoes. Among these, 26 showed inhibition before immunoglobulin depletion. Despite substantial immunoglobulin removal, 4 samples still exhibited notable inhibition, while 22 had reduced blocking activity. Testing against heterologous strains revealed some plasma samples with broad TBI and others with strain-specific TBI. CONCLUSIONS Our findings indicate that naturally acquired TBI is mainly mediated by antibodies, with possible contributions from other serum factors. The transmission-blocking activity of plasma samples varied by the tested parasite strain, suggesting single polymorphic or multiple targets for naturally acquired TBI. These observations improve understanding of immunity against P vivax and hold implications for transmission-blocking vaccine development.
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Affiliation(s)
| | | | - Wang Nguitragool
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Tomoko Ishino
- Department of Parasitology and Tropical Medicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Mayumi Tachibana
- Division of Molecular Parasitology, Proteo-Science Center, Ehime University, Toon, Ehime, Japan
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
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6
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Lampejo T. Monoclonal antibodies for the prevention of Plasmodium falciparum malaria: a multi-target approach? Infect Dis (Lond) 2024; 56:73-77. [PMID: 37921336 DOI: 10.1080/23744235.2023.2274897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 10/19/2023] [Indexed: 11/04/2023] Open
Abstract
This article discusses the need for novel additional preventative strategies in malaria focusing on the potential role for monoclonal antibodies in disease prevention and putative strategies for their development and use in Plasmodium falciparum malaria.
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Affiliation(s)
- Temi Lampejo
- Department of Infection Sciences, King's College Hospital, London, UK
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7
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Bansal GP, Kumar N. Immune mechanisms targeting malaria transmission: opportunities for vaccine development. Expert Rev Vaccines 2024; 23:645-654. [PMID: 38888098 PMCID: PMC11472754 DOI: 10.1080/14760584.2024.2369583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 06/14/2024] [Indexed: 06/20/2024]
Abstract
INTRODUCTION Malaria continues to remain a major global health problem with nearly a quarter of a billion clinical cases and more than 600,000 deaths in 2022. There has been significant progress toward vaccine development, however, poor efficacy of approved vaccines requiring multiple immunizing doses emphasizes the need for continued efforts toward improved vaccines. Progress to date, nonetheless, has provided impetus for malaria elimination. AREAS COVERED In this review we will focus on diverse immune mechanisms targeting gametocytes in the human host and gametocyte-mediated malaria transmission via the mosquito vector. EXPERT OPINION To march toward the goal of malaria elimination it will be critical to target the process of malaria transmission by mosquitoes, mediated exclusively by the sexual stages, i.e. male, and female gametocytes, ingested from infected vertebrate host. Studies over several decades have established antigens in the parasite sexual stages developing in the mosquito midgut as attractive targets for the development of transmission blocking vaccines (TBVs). Immune clearance of gametocytes in the vertebrate host can synergize with TBVs and directly aid in maintaining effective transmission reducing immune potential.
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Affiliation(s)
- Geetha P. Bansal
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, 70122, USA
| | - Nirbhay Kumar
- Department of Global Health, The Milken Institute School of Public Health, George Washington University, Washington DC, 20052, USA
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8
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Kengne-Ouafo JA, Bah SY, Kemp A, Stewart L, Amenga-Etego L, Deitsch KW, Rayner JC, Billker O, Binka FN, Sutherland CJ, Awandare GA, Urban BC, Dinko B. The global transcriptome of Plasmodium falciparum mid-stage gametocytes (stages II-IV) appears largely conserved and gametocyte-specific gene expression patterns vary in clinical isolates. Microbiol Spectr 2023; 11:e0382022. [PMID: 37698406 PMCID: PMC10581088 DOI: 10.1128/spectrum.03820-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 07/09/2023] [Indexed: 09/13/2023] Open
Abstract
Our overall understanding of the developmental biology of malaria parasites has been greatly enhanced by recent advances in transcriptomic analysis. However, most of these investigations rely on laboratory strains (LS) that were adapted into in vitro culture many years ago, and the transcriptomes of clinical isolates (CI) circulating in human populations have not been assessed. In this study, RNA-seq was used to compare the global transcriptome of mid-stage gametocytes derived from three short-term cultured CI, with gametocytes derived from the NF54 reference laboratory strain. The core transcriptome appeared to be consistent between CI- and LS-derived gametocyte preparations, but some important differences were also observed. A majority of gametocyte-specific genes (43/53) appear to have relatively higher expression in CI-derived gametocytes than in LS-derived gametocytes, but a K-means clustering analysis showed that genes involved in flagellum- and microtubule-based processes (movement/motility) were more abundant in both groups, albeit with some differences between them. In addition, gametocytes from one CI described as CI group II gametocytes (CI:GGII) showed gene expression variation in the form of reduced gametocyte-specific gene expression compared to the other two CI-derived gametocytes (CI gametocyte group I, CI:GGI), although the mixed developmental stages used in our study is a potential confounder, only partially mitigated by the inclusion of multiple replicates for each CI. Overall, our study suggests that there may be subtle differences in the gene expression profiles of mid-stage gametocytes from CI relative to the NF54 reference strain of Plasmodium falciparum. Thus, it is necessary to deploy gametocyte-producing clinical parasite isolates to fully understand the diversity of gene expression strategies that may occur during the sequestered development of parasite sexual stages. IMPORTANCE Maturing gametocytes of Plasmodium falciparum are known to sequester away from peripheral circulation into the bone marrow until they are mature. Blocking gametocyte sequestration can prevent malaria transmission from humans to mosquitoes, but most studies aim to understand gametocyte development utilizing long-term adapted laboratory lines instead of clinical isolates. This is a particular issue for our understanding of the sexual stages, which are known to decrease rapidly during adaptation to long-term culture, meaning that many LS are unable to produce transmissible gametocytes. Using RNA-seq, we investigated the global transcriptome of mid-stage gametocytes derived from three clinical isolates and a reference strain (NF54). This identified important differences in gene expression profiles between immature gametocytes of CI and the NF54 reference strain of P. falciparum, suggesting increased investment in gametocytogenesis in clinical isolates. Our transcriptomic data highlight the use of clinical isolates in studying the morphological, cellular features and molecular biology of gametocytes.
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Affiliation(s)
- Jonas A. Kengne-Ouafo
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Saikou Y. Bah
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
- Vaccine and Immunity Theme, MRC Unit The Gambia at London School of Hygiene & Tropical Medicine, Banjul, Gambia
| | - Alison Kemp
- Malaria Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
| | - Lindsay Stewart
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Lucas Amenga-Etego
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Kirk W. Deitsch
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York City, New York, USA
| | - Julian C. Rayner
- Malaria Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Oliver Billker
- Malaria Programme, Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, United Kingdom
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Fred N. Binka
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Ho, Ghana
| | - Colin J. Sutherland
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Gordon A. Awandare
- Department of Biochemistry, Cell and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Britta C. Urban
- Faculty of Biological Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Bismarck Dinko
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana
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Salinas ND, Ma R, Dickey TH, McAleese H, Ouahes T, Long CA, Miura K, Lambert LE, Tolia NH. A potent and durable malaria transmission-blocking vaccine designed from a single-component 60-copy Pfs230D1 nanoparticle. NPJ Vaccines 2023; 8:124. [PMID: 37596283 PMCID: PMC10439124 DOI: 10.1038/s41541-023-00709-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 07/12/2023] [Indexed: 08/20/2023] Open
Abstract
Malaria transmission-blocking vaccines (TBVs) reduce disease transmission by breaking the continuous cycle of infection between the human host and the mosquito vector. Domain 1 (D1) of Pfs230 is a leading TBV candidate and comprises the majority of transmission-reducing activity (TRA) elicited by Pfs230. Here we show that the fusion of Pfs230D1 to a 60-copy multimer of the catalytic domain of dihydrolipoyl acetyltransferase protein (E2p) results in a single-component nanoparticle composed of 60 copies of the fusion protein with high stability, homogeneity, and production yields. The nanoparticle presents a potent human transmission-blocking epitope within Pfs230D1, indicating the antigen is correctly oriented on the surface of the nanoparticle. Two vaccinations of New Zealand White rabbits with the Pfs230D1 nanoparticle elicited a potent and durable antibody response with high TRA when formulated in two distinct adjuvants suitable for translation to human use. This single-component nanoparticle vaccine may play a key role in malaria control and has the potential to improve production pipelines and the cost of manufacturing of a potent and durable TBV.
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Affiliation(s)
- Nichole D Salinas
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Rui Ma
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Thayne H Dickey
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Holly McAleese
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tarik Ouahes
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Lynn E Lambert
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Niraj H Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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10
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El-Moamly AA, El-Sweify MA. Malaria vaccines: the 60-year journey of hope and final success-lessons learned and future prospects. Trop Med Health 2023; 51:29. [PMID: 37198702 DOI: 10.1186/s41182-023-00516-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 04/18/2023] [Indexed: 05/19/2023] Open
Abstract
BACKGROUND The world has made great strides towards beating malaria, although about half of the world population is still exposed to the risk of contracting malaria. Developing an effective malaria vaccine was a huge challenge for medical science. In 2021 the World Health Organization (WHO) approved the first malaria vaccine, RTS,S/AS01 vaccine (Mosquirix™), for widespread use. This review highlights the history of development, and the different approaches and types of malaria vaccines, and the literature to date. It covers the developmental stages of RTS,S/AS01 and recommends steps for its deployment. The review explores other potential vaccine candidates and their status, and suggests options for their further development. It also recommends future roles for vaccines in eradicating malaria. Questions remain on how RTS,S vaccine will work in widespread use and how it can best be utilized to benefit vulnerable communities. CONCLUSION Malaria vaccines have been in development for almost 60 years. The RTS,S/AS01 vaccine has now been approved, but cannot be a stand-alone solution. Development should continue on promising candidates such as R21, PfSPZ and P. vivax vaccines. Multi-component vaccines may be a useful addition to other malaria control techniques in achieving eradication of malaria.
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Affiliation(s)
- Amal A El-Moamly
- Department of Medical Parasitology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
| | - Mohamed A El-Sweify
- Department of Medical Microbiology and Immunology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
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11
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B-Cell Epitope Mapping of the Plasmodium falciparum Malaria Vaccine Candidate GMZ2.6c in a Naturally Exposed Population of the Brazilian Amazon. Vaccines (Basel) 2023; 11:vaccines11020446. [PMID: 36851323 PMCID: PMC9966924 DOI: 10.3390/vaccines11020446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/09/2023] [Accepted: 02/13/2023] [Indexed: 02/17/2023] Open
Abstract
The GMZ2.6c malaria vaccine candidate is a multi-stage P. falciparum chimeric protein that contains a fragment of the sexual-stage Pfs48/45-6C protein genetically fused to GMZ2, an asexual-stage vaccine construction consisting of the N-terminal region of the glutamate-rich protein (GLURP) and the C-terminal region of the merozoite surface protein-3 (MSP-3). Previous studies showed that GMZ2.6c is widely recognized by antibodies from Brazilian exposed individuals and that its components are immunogenic in natural infection by P. falciparum. In addition, anti-GMZ2.6c antibodies increase with exposure to infection and may contribute to parasite immunity. Therefore, identifying epitopes of proteins recognized by antibodies may be an important tool for understanding protective immunity. Herein, we identify and validate the B-cell epitopes of GMZ2.6c as immunogenic and immunodominant in individuals exposed to malaria living in endemic areas of the Brazilian Amazon. Specific IgG antibodies and subclasses against MSP-3, GLURP, and Pfs48/45 epitopes were detected by ELISA using synthetic peptides corresponding to B-cell epitopes previously described for MSP-3 and GLURP or identified by BepiPred for Pfs48/45. The results showed that the immunodominant epitopes were P11 from GLURP and MSP-3c and DG210 from MSP-3. The IgG1 and IgG3 subclasses were preferentially induced against these epitopes, supporting previous studies that these proteins are targets for cytophilic antibodies, important for the acquisition of protective immunity. Most individuals presented detectable IgG antibodies against Pfs48/45a and/or Pfs48/45b, validating the prediction of linear B-cell epitopes. The higher frequency and antibody levels against different epitopes from GLURP, MSP-3, and Pfs48/45 provide additional information that may suggest the relevance of GMZ2.6c as a multi-stage malaria vaccine candidate.
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12
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Fabra-García A, Hailemariam S, de Jong RM, Janssen K, Teelen K, van de Vegte-Bolmer M, van Gemert GJ, Ivanochko D, Semesi A, McLeod B, Vos MW, de Bruijni MHC, Bolscher JM, Szabat M, Vogt S, Kraft L, Duncan S, Kamya MR, Feeney ME, Jagannathan P, Greenhouse B, Dechering KJ, Sauerwein RW, King CR, MacGill RS, Bousema T, Julien JP, Jore MM. Highly potent, naturally acquired human monoclonal antibodies against Pfs48/45 block Plasmodium falciparum transmission to mosquitoes. Immunity 2023; 56:406-419.e7. [PMID: 36792574 PMCID: PMC9942873 DOI: 10.1016/j.immuni.2023.01.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 11/05/2022] [Accepted: 01/11/2023] [Indexed: 02/16/2023]
Abstract
Malaria transmission-blocking vaccines (TBVs) aim to induce antibodies that interrupt malaria parasite development in the mosquito, thereby blocking onward transmission, and provide a much-needed tool for malaria control and elimination. The parasite surface protein Pfs48/45 is a leading TBV candidate. Here, we isolated and characterized a panel of 81 human Pfs48/45-specific monoclonal antibodies (mAbs) from donors naturally exposed to Plasmodium parasites. Genetically diverse mAbs against each of the three domains (D1-D3) of Pfs48/45 were identified. The most potent mAbs targeted D1 and D3 and achieved >80% transmission-reducing activity in standard membrane-feeding assays, at 10 and 2 μg/mL, respectively. Co-crystal structures of D3 in complex with four different mAbs delineated two conserved protective epitopes. Altogether, these Pfs48/45-specific human mAbs provide important insight into protective and non-protective epitopes that can further our understanding of transmission and inform the design of refined malaria transmission-blocking vaccine candidates.
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Affiliation(s)
| | - Sophia Hailemariam
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Roos M de Jong
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands
| | - Kirsten Janssen
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands
| | - Karina Teelen
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands
| | | | | | - Danton Ivanochko
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | - Anthony Semesi
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada
| | - Brandon McLeod
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | | | | | | | | | | | - Lucas Kraft
- AbCellera Biologics Inc., Vancouver, BC, Canada
| | | | - Moses R Kamya
- Infectious Disease Research Collaboration, Kampala, Uganda
| | - Margaret E Feeney
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA; Department of Pediatrics, University of California, San Francisco, San Francisco, CA, USA
| | - Prasanna Jagannathan
- Department of Microbiology and Immunology, Stanford University, Stanford, CA, USA
| | - Bryan Greenhouse
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | | | | | - C Richter King
- PATH's Malaria Vaccine Initiative, Washington, DC 20001, USA
| | | | - Teun Bousema
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands.
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada; Department of Immunology, University of Toronto, Toronto, ON, Canada.
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands.
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13
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Ko KT, Lennartz F, Mekhaiel D, Guloglu B, Marini A, Deuker DJ, Long CA, Jore MM, Miura K, Biswas S, Higgins MK. Structure of the malaria vaccine candidate Pfs48/45 and its recognition by transmission blocking antibodies. Nat Commun 2022; 13:5603. [PMID: 36153317 PMCID: PMC9509318 DOI: 10.1038/s41467-022-33379-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 09/14/2022] [Indexed: 12/05/2022] Open
Abstract
An effective malaria vaccine remains a global health priority and vaccine immunogens which prevent transmission of the parasite will have important roles in multi-component vaccines. One of the most promising candidates for inclusion in a transmission-blocking malaria vaccine is the gamete surface protein Pfs48/45, which is essential for development of the parasite in the mosquito midgut. Indeed, antibodies which bind Pfs48/45 can prevent transmission if ingested with the parasite as part of the mosquito bloodmeal. Here we present the structure of full-length Pfs48/45, showing its three domains to form a dynamic, planar, triangular arrangement. We reveal where transmission-blocking and non-blocking antibodies bind on Pfs48/45. Finally, we demonstrate that antibodies which bind across this molecule can be transmission-blocking. These studies will guide the development of future Pfs48/45-based vaccine immunogens.
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Affiliation(s)
- Kuang-Ting Ko
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford, OX1 3QU, UK
- Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Rd, Oxford, OX1 3QU, UK
| | - Frank Lennartz
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford, OX1 3QU, UK
| | - David Mekhaiel
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Bora Guloglu
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford, OX1 3QU, UK
- Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Rd, Oxford, OX1 3QU, UK
| | - Arianna Marini
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Danielle J Deuker
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Carole A Long
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, USA
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Kazutoyo Miura
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, USA
| | - Sumi Biswas
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK.
| | - Matthew K Higgins
- Department of Biochemistry, South Parks Road, University of Oxford, Oxford, OX1 3QU, UK.
- Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Rd, Oxford, OX1 3QU, UK.
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14
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McLeod B, Mabrouk MT, Miura K, Ravichandran R, Kephart S, Hailemariam S, Pham TP, Semesi A, Kucharska I, Kundu P, Huang WC, Johnson M, Blackstone A, Pettie D, Murphy M, Kraft JC, Leaf EM, Jiao Y, van de Vegte-Bolmer M, van Gemert GJ, Ramjith J, King CR, MacGill RS, Wu Y, Lee KK, Jore MM, King NP, Lovell JF, Julien JP. Vaccination with a structure-based stabilized version of malarial antigen Pfs48/45 elicits ultra-potent transmission-blocking antibody responses. Immunity 2022; 55:1680-1692.e8. [PMID: 35977542 PMCID: PMC9487866 DOI: 10.1016/j.immuni.2022.07.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 07/07/2022] [Accepted: 07/18/2022] [Indexed: 02/08/2023]
Abstract
Malaria transmission-blocking vaccines (TBVs) aim to elicit human antibodies that inhibit sporogonic development of Plasmodium falciparum in mosquitoes, thereby preventing onward transmission. Pfs48/45 is a leading clinical TBV candidate antigen and is recognized by the most potent transmission-blocking monoclonal antibody (mAb) yet described; still, clinical development of Pfs48/45 antigens has been hindered, largely by its poor biochemical characteristics. Here, we used structure-based computational approaches to design Pfs48/45 antigens stabilized in the conformation recognized by the most potently inhibitory mAb, achieving >25°C higher thermostability compared with the wild-type protein. Antibodies elicited in mice immunized with these engineered antigens displayed on liposome-based or protein nanoparticle-based vaccine platforms exhibited 1-2 orders of magnitude superior transmission-reducing activity, compared with immunogens bearing the wild-type antigen, driven by improved antibody quality. Our data provide the founding principles for using molecular stabilization solely from antibody structure-function information to drive improved immune responses against a parasitic vaccine target.
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Affiliation(s)
- Brandon McLeod
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Moustafa T Mabrouk
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Rashmi Ravichandran
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Sally Kephart
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Sophia Hailemariam
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Thao P Pham
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Anthony Semesi
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Iga Kucharska
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Prasun Kundu
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Wei-Chiao Huang
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Max Johnson
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Alyssa Blackstone
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Deleah Pettie
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Michael Murphy
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - John C Kraft
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Elizabeth M Leaf
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Yang Jiao
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | | | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Jordache Ramjith
- Radboud Institute for Health Sciences, Department for Health Evidence, Biostatistics Section, Radboud University Medical Center, Nijmegen, the Netherlands
| | - C Richter King
- PATH's Malaria Vaccine Initiative, 455 Massachusetts Avenue NW Suite 1000, Washington, DC 20001, USA
| | - Randall S MacGill
- PATH's Malaria Vaccine Initiative, 455 Massachusetts Avenue NW Suite 1000, Washington, DC 20001, USA
| | - Yimin Wu
- PATH's Malaria Vaccine Initiative, 455 Massachusetts Avenue NW Suite 1000, Washington, DC 20001, USA
| | - Kelly K Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Neil P King
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA; Institute for Protein Design, University of Washington, Seattle, WA 98195, USA
| | - Jonathan F Lovell
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, NY 14260, USA
| | - Jean-Philippe Julien
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Department of Immunology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
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15
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Sauerwein RW, Plieskatt J, Theisen M. 40 Years of Pfs48/45 Research as a Transmission-Blocking Vaccine Target of Plasmodium falciparum Malaria. Am J Trop Med Hyg 2022; 107:tpmd211320. [PMID: 35895389 DOI: 10.4269/ajtmh.21-1320] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/17/2022] [Indexed: 02/18/2024] Open
Abstract
In the early 1980s, Richard Carter was among the first researchers to identify the sexual stage-specific Pfs48/45 protein, leading to the identification of target epitopes. Carter predicted its tertiary conformation while involved in a number of studies on naturally acquired sexual stage-specific antibodies. Pfs48/45 is a cysteine-rich surface protein of sexual stages of Plasmodium falciparum that plays a critical role in male gamete fertility. Antibodies against Pfs48/45 prevent parasite development in the mosquito vector, and therefore prevent the spread of malaria in the population. Since the gene was sequenced in the early 1990s, Pfs48/45 has been considered a prime target candidate for a malaria transmission-blocking vaccine. However, major manufacturing challenges-in particular, difficulty realizing satisfactory yields of a properly folded protein for the induction of functional antibodies-delayed clinical development significantly. These challenges were met roughly 20 years later. The first clinical trial with a Pfs48/45 subunit vaccine (R0.6C) was started in the Netherlands in early 2021. The excellent contributions to the long and winding path of Pfs48/45 research by Richard Carter are well recognized and are an integrated part of his seminal contributions to unraveling Plasmodium sexual stage biology.
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Affiliation(s)
| | - Jordan Plieskatt
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Centre for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
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16
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O’Flaherty K, Chan JA, Cutts JC, Zaloumis SG, Ashley EA, Phyo AP, Drew DR, Dondorp AM, Day NP, Dhorda M, Fairhurst RM, Lim P, Amaratunga C, Pukrittayakamee S, Hien TT, Htut Y, Mayxay M, Faiz MA, Mokuolu OA, Onyamboko MA, Fanello C, Takashima E, Tsuboi T, Theisen M, Nosten F, Beeson JG, Simpson JA, White NJ, Fowkes FJI. Anti-Gametocyte Antigen Humoral Immunity and Gametocytemia During Treatment of Uncomplicated Falciparum Malaria: A Multi-National Study. Front Cell Infect Microbiol 2022; 12:804470. [PMID: 35463638 PMCID: PMC9022117 DOI: 10.3389/fcimb.2022.804470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/11/2022] [Indexed: 11/16/2022] Open
Abstract
Introduction Understanding the human immune response to Plasmodium falciparum gametocytes and its association with gametocytemia is essential for understanding the transmission of malaria as well as progressing transmission blocking vaccine candidates. Methods In a multi-national clinical efficacy trial of artemisinin therapies (13 sites of varying transmission over South-East Asia and Africa), we measured Immunoglobulin G (IgG) responses to recombinant P. falciparum gametocyte antigens expressed on the gametocyte plasma membrane and leading transmission blocking vaccine candidates Pfs230 (Pfs230c and Pfs230D1M) and Pfs48/45 at enrolment in 1,114 participants with clinical falciparum malaria. Mixed effects linear and logistic regression were used to determine the association between gametocyte measures (gametocytemia and gametocyte density) and antibody outcomes at enrolment. Results Microscopy detectable gametocytemia was observed in 11% (127/1,114) of participants at enrolment, and an additional 9% (95/1,114) over the follow-up period (up to day 42) (total 20% of participants [222/1,114]). IgG levels in response to Pfs230c, Pfs48/45 and Pfs230D1M varied across study sites at enrolment (p < 0.001), as did IgG seroprevalence for anti-Pfs230c and D1M IgG (p < 0.001), but not for anti-Pfs48/45 IgG (p = 0.159). In adjusted analyses, microscopy detectable gametocytemia at enrolment was associated with an increase in the odds of IgG seropositivity to the three gametocyte antigens (Pfs230c OR [95% CI], p: 1.70 [1.10, 2.62], 0.017; Pfs48/45: 1.45 [0.85, 2.46], 0.174; Pfs230D1M: 1.70 [1.03, 2.80], 0.037), as was higher gametocyte density at enrolment (per two-fold change in gametocyte density Pfs230c OR [95% CI], p: 1.09 [1.02, 1.17], 0.008; Pfs48/45: 1.05 [0.98, 1.13], 0.185; Pfs230D1M: 1.07 [0.99, 1.14], 0.071). Conclusion Pfs230 and Pfs48/45 antibodies are naturally immunogenic targets associated with patent gametocytemia and increasing gametocyte density across multiple malaria endemic settings, including regions with emerging artemisinin-resistant P. falciparum.
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Affiliation(s)
| | - Jo-Anne Chan
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
- Department of Immunology, Monash University, Melbourne, VIC, Australia
| | - Julia C. Cutts
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
| | - Sophie G. Zaloumis
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Elizabeth A. Ashley
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Damien R. Drew
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
| | - Arjen M. Dondorp
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Nicholas P. Day
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Mehul Dhorda
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- WorldWide Antimalarial Resistance Network, Asia-Pacific Regional Centre, Bangkok, Thailand
| | - Rick M. Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | - Pharath Lim
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | - Chanaki Amaratunga
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, United States
| | | | - Tran Tinh Hien
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Oxford University Clinical Research Unit, Hospital for Tropical Diseases, Ho Chi Minh City, Vietnam
| | - Ye Htut
- Department of Medical Research, Ministry of Health and Sports, Yangon, Myanmar
| | - Mayfong Mayxay
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust-Research Unit, Mahosot Hospital, Vientiane, Laos
- Institute of Research and Education Development, University of Health Sciences, Vientiane, Laos
| | - M. Abul Faiz
- Malaria Research Group and Dev Care Foundation, Chittagong, Bangladesh
| | - Olugbenga A. Mokuolu
- Department of Paediatrics and Child Health, University of Ilorin, Ilorin, Nigeria
| | - Marie A. Onyamboko
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Caterina Fanello
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Kinshasa School of Public Health, University of Kinshasa, Kinshasa, Democratic Republic of Congo
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Francois Nosten
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Shoklo Malaria Research Unit, Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot, Thailand
| | - James G. Beeson
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Department of Medicine, The University of Melbourne, Melbourne, VIC, Australia
- Department of Immunology, Monash University, Melbourne, VIC, Australia
- Department of Microbiology and Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Julie A. Simpson
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Nicholas J. White
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Freya J. I. Fowkes
- Life Sciences, Burnet Institute, Melbourne, VIC, Australia
- Centre for Epidemiology and Biostatistics, School of Population and Global Health, The University of Melbourne, Melbourne, VIC, Australia
- Department of Infectious Diseases and Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, VIC, Australia
- *Correspondence: Freya J. I. Fowkes,
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17
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Muthui MK, Takashima E, Omondi BR, Kinya C, Muasya WI, Nagaoka H, Mwai KW, Orindi B, Wambua J, Bousema T, Drakeley C, Blagborough AM, Marsh K, Bejon P, Kapulu MC. Characterization of Naturally Acquired Immunity to a Panel of Antigens Expressed in Mature P. falciparum Gametocytes. Front Cell Infect Microbiol 2021; 11:774537. [PMID: 34869075 PMCID: PMC8633105 DOI: 10.3389/fcimb.2021.774537] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 10/25/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction Naturally acquired immune responses against antigens expressed on the surface of mature gametocytes develop in individuals living in malaria-endemic areas. Evidence suggests that such anti-gametocyte immunity can block the development of the parasite in the mosquito, thus playing a role in interrupting transmission. A better comprehension of naturally acquired immunity to these gametocyte antigens can aid the development of transmission-blocking vaccines and improve our understanding of the human infectious reservoir. Methods Antigens expressed on the surface of mature gametocytes that had not previously been widely studied for evidence of naturally acquired immunity were identified for protein expression alongside Pfs230-C using either the mammalian HEK293E or the wheat germ cell-free expression systems. Where there was sequence variation in the candidate antigens (3D7 vs a clinical isolate PfKE04), both variants were expressed. ELISA was used to assess antibody responses against these antigens, as well as against crude stage V gametocyte extract (GE) and AMA1 using archived plasma samples from individuals recruited to participate in malaria cohort studies. We analyzed antibody levels (estimated from optical density units using a standardized ELISA) and seroprevalence (defined as antibody levels greater than three standard deviations above the mean levels of a pool of malaria naïve sera). We described the dynamics of antibody responses to these antigens by identifying factors predictive of antibody levels using linear regression models. Results Of the 25 antigens selected, seven antigens were produced successfully as recombinant proteins, with one variant antigen, giving a total of eight proteins for evaluation. Antibodies to the candidate antigens were detectable in the study population (N = 216), with seroprevalence ranging from 37.0% (95% CI: 30.6%, 43.9%) for PSOP1 to 77.8% (95% CI: 71.6%, 83.1%) for G377 (3D7 variant). Responses to AMA1 and GE were more prevalent than those to the gametocyte proteins at 87.9% (95% CI: 82.8%, 91.9%) and 88.3% (95% CI: 83.1%, 92.4%), respectively. Additionally, both antibody levels and breadth of antibody responses were associated with age and concurrent parasitaemia. Conclusion Age and concurrent parasitaemia remain important determinants of naturally acquired immunity to gametocyte antigens. Furthermore, we identify novel candidates for transmission-blocking activity evaluation.
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Affiliation(s)
- Michelle K Muthui
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Brian R Omondi
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Christine Kinya
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - William I Muasya
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Kennedy W Mwai
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya.,School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Benedict Orindi
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Juliana Wambua
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, Netherlands
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Andrew M Blagborough
- Division of Microbiology and Parasitology, Department of Pathology, Cambridge University, Tennis Court Road, Cambridge, United Kingdom
| | - Kevin Marsh
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Philip Bejon
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Melissa C Kapulu
- Department of Biosciences, Kenya Medical Research Institute (KEMRI)-Wellcome Trust Programme, Kilifi, Kenya.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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18
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Ayanful-Torgby R, Sarpong E, Abagna HB, Donu D, Obboh E, Mensah BA, Adjah J, Williamson KC, Amoah LE. Persistent Plasmodium falciparum infections enhance transmission-reducing immunity development. Sci Rep 2021; 11:21380. [PMID: 34725428 PMCID: PMC8560775 DOI: 10.1038/s41598-021-00973-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/21/2021] [Indexed: 11/09/2022] Open
Abstract
Subclinical infections that serve as reservoir populations to drive transmission remain a hurdle to malaria control. Data on infection dynamics in a geographical area is required to strategically design and implement malaria interventions. In a longitudinal cohort, we monitored Plasmodium falciparum infection prevalence and persistence, and anti-parasite immunity to gametocyte and asexual antigens for 10 weeks. Of the 100 participants, only 11 were never infected, whilst 16 had persistent infections detected by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), and one participant had microscopic parasites at all visits. Over 70% of the participants were infected three or more times, and submicroscopic gametocyte prevalence was high, ≥ 48% of the parasite carriers. Naturally induced responses against recombinant Pfs48/45.6C, Pfs230proC, and EBA175RIII-V antigens were not associated with either infection status or gametocyte carriage, but the antigen-specific IgG titers inversely correlated with parasite and gametocyte densities consistent with partial immunity. Longitudinal analysis of gametocyte diversity indicated at least four distinct clones circulated throughout the study period. The high prevalence of children infected with distinct gametocyte clones coupled with marked variation in infection status at the individual level suggests ongoing transmission and should be targeted in malaria control programs.
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Affiliation(s)
- Ruth Ayanful-Torgby
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
| | | | - Hamza B Abagna
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Dickson Donu
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | | | - Benedicta A Mensah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Joshua Adjah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Kim C Williamson
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Linda E Amoah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana.
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19
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Preclinical development of a Pfs230-Pfs48/45 chimeric malaria transmission-blocking vaccine. NPJ Vaccines 2021; 6:120. [PMID: 34642303 PMCID: PMC8511065 DOI: 10.1038/s41541-021-00383-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 09/17/2021] [Indexed: 11/09/2022] Open
Abstract
The Plasmodium falciparum Pfs230 and Pfs48/45 proteins are leading candidates for a malaria transmission-blocking vaccine (TBV). Previously, we showed that a Pfs230–Pfs48/45 fusion protein elicits higher levels of functional antibodies than the individual antigens, but low yields hampered progression to clinical evaluation. Here we identified a modified construct (ProC6C) with a circumsporozoite protein (CSP) repeat-linker sequence that enhances expression. A scalable and reproducible process in the Lactococcus lactis expression system was developed and ProC6C was successfully transferred for manufacturing under current Good Manufacturing Practices (cGMP). In addition, a panel of analytical assays for release and stability were developed. Intact mass spectrometry analysis and multiangle light scattering showed that the protein contained correct disulfide bonds and was monomeric. Immunogenicity studies in mice showed that the ProC6C adsorbed to Alhydrogel®, with or without Matrix-MTM, elicited functional antibodies that reduced transmission to mosquitoes and sporozoite invasion of human hepatocytes. Altogether, our data support manufacture and clinical evaluation of ProC6C as a multistage malaria-vaccine candidate.
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20
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Tripathi AK, Oakley MS, Verma N, Mlambo G, Zheng H, Meredith SM, Essuman E, Puri A, Skelton RA, Takeda K, Majam V, Quakyi IA, Locke E, Morin M, Miura K, Long CA, Kumar S. Plasmodium falciparum Pf77 and male development gene 1 as vaccine antigens that induce potent transmission-reducing antibodies. Sci Transl Med 2021; 13:eabg2112. [PMID: 34108248 PMCID: PMC11018285 DOI: 10.1126/scitranslmed.abg2112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 04/22/2021] [Indexed: 12/14/2022]
Abstract
Malaria vaccines that disrupt the Plasmodium life cycle in mosquitoes and reduce parasite transmission in endemic areas are termed transmission-blocking vaccines (TBVs). Despite decades of research, there are only a few Plasmodium falciparum antigens that indisputably and reproducibly demonstrate transmission-blocking immunity. So far, only two TBV candidates have advanced to phase 1/2 clinical testing with limited success. By applying an unbiased transcriptomics-based approach, we have identified Pf77 and male development gene 1 (PfMDV-1) as two P. falciparum TBV antigens that, upon immunization, induced antibodies that caused reductions in oocyst counts in Anopheles mosquito midguts in a standard membrane feeding assay. In-depth studies were performed to characterize the genetic diversity of, stage-specific expression by, and natural immunity to these two molecules to evaluate their suitability as TBV candidates. Pf77 and PfMDV-1 display limited antigenic polymorphism, are pan-developmentally expressed within the parasite, and induce naturally occurring antibodies in Ghanaian adults, which raises the prospect of natural boosting of vaccine-induced immune response in endemic regions. Together, these biological properties suggest that Pf77 and PfMDV-1 may warrant further investigation as TBV candidates.
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Affiliation(s)
- Abhai K Tripathi
- Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Miranda S Oakley
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Nitin Verma
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Godfree Mlambo
- Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Hong Zheng
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Scott M Meredith
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Edward Essuman
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Ankit Puri
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Richard A Skelton
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Kazuyo Takeda
- Division of Bacterial, Parasitic, and Allergenic Products, Office of Vaccines Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Victoria Majam
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | | | - Emily Locke
- PATH-Malaria Vaccine Initiative, Washington, DC 20001, USA
| | | | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA
| | - Sanjai Kumar
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA.
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21
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Touray AO, Mobegi VA, Wamunyokoli F, Butungi H, Herren JK. Prevalence of asymptomatic P. falciparum gametocyte carriage among school children in Mbita, Western Kenya and assessment of the association between gametocyte density, multiplicity of infection and mosquito infection prevalence. Wellcome Open Res 2021; 5:259. [PMID: 33959684 PMCID: PMC8078214 DOI: 10.12688/wellcomeopenres.16299.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2021] [Indexed: 12/02/2022] Open
Abstract
Background: Asymptomatic Plasmodium falciparum gametocyte carriers are reservoirs for sustaining transmission in malaria endemic regions. Gametocyte presence in the host peripheral blood is a predictor of capacity to transmit malaria. However, it does not always directly translate to mosquito infectivity. Factors that affect mosquito infectivity include, gametocyte sex-ratio and density, multiplicity of infection (MOI), and host and vector anti-parasite immunity. We assess the prevalence of gametocyte carriage and some of its associated risk factors among asymptomatic schoolchildren in Western Kenya and to further analyse the association between gametocyte density, multiplicity of infection (MOI) and mosquito infection prevalence. Methods: P. falciparum parasite infections were detected by RDT (Rapid Diagnostic Test) and microscopy among schoolchildren (5-15 years old). Blood from 37 microscopy positive gametocyte carriers offered to laboratory reared An. gambiae s.l. mosquitoes. A total of 3395 fully fed mosquitoes were screened for Plasmodium sporozoites by ELISA. P. falciparum was genotyped using 10 polymorphic microsatellite markers. The association between MOI and gametocyte density and mosquito infection prevalence was investigated. Results: A significantly higher prevalence of P. falciparum infection was found in males 31.54% (764/2422) ( p-value < 0.001) compared to females 26.72% (657/2459). The microscopic gametocyte prevalence among the study population was 2% (84/4881). Children aged 5-9 years have a higher prevalence of gametocyte carriage (odds ratios = 2.1 [95% CI = 1.3-3.4], P = 0.002) as compared to children aged 10-15 years. After offering gametocyte positive blood to An. gambiae s.l. by membrane feeding assay, our results indicated that 68.1% of the variation in mosquito infection prevalence was accounted for by gametocyte density and MOI (R-SQR. = 0.681, p < 0.001). Conclusions: We observed a higher risk of gametocyte carriage among the younger children (5-9 years). Gametocyte density and MOI significantly predicted mosquito infection prevalence.
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Affiliation(s)
- Abdoulie O. Touray
- Department of Molecular Biology and Biotechnology, Institute of Basic Sciences, Technology and Innovation, Pan African University (PAUSTI), Nairobi, Kenya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Victor A. Mobegi
- Department of Biochemistry, School of Medicine, University of Nairobi, Nairobi, Kenya
| | - Fred Wamunyokoli
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Hellen Butungi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg, South Africa
| | - Jeremy K. Herren
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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22
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Corbett Y, Parapini S, Perego F, Messina V, Delbue S, Misiano P, Falchi M, Silvestrini F, Taramelli D, Basilico N, D'Alessandro S. Phagocytosis and activation of bone marrow-derived macrophages by Plasmodium falciparum gametocytes. Malar J 2021; 20:81. [PMID: 33568138 PMCID: PMC7874634 DOI: 10.1186/s12936-021-03589-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 01/08/2021] [Indexed: 02/01/2023] Open
Abstract
Background The innate immune response against various life cycle stages of the malaria parasite plays an important role in protection against the disease and regulation of its severity. Phagocytosis of asexual erythrocytic stages is well documented, but little and contrasting results are available about phagocytic clearance of sexual stages, the gametocytes, which are responsible for the transmission of the parasites from humans to mosquitoes. Similarly, activation of host macrophages by gametocytes has not yet been carefully addressed. Methods Phagocytosis of early or late Plasmodium falciparum gametocytes was evaluated through methanol fixed cytospin preparations of immortalized mouse C57Bl/6 bone marrow-derived macrophages treated for 2 h with P. falciparum and stained with Giemsa, and it was confirmed through a standardized bioluminescent method using the transgenic P. falciparum 3D7elo1-pfs16-CBG99 strain. Activation was evaluated by measuring nitric oxide or cytokine levels in the supernatants of immortalized mouse C57Bl/6 bone marrow-derived macrophages treated with early or late gametocytes. Results The results showed that murine bone marrow-derived macrophages can phagocytose both early and late gametocytes, but only the latter were able to induce the production of inflammatory mediators, specifically nitric oxide and the cytokines tumour necrosis factor and macrophage inflammatory protein 2. Conclusions These results support the hypothesis that developing gametocytes interact in different ways with innate immune cells of the host. Moreover, the present study proposes that early and late gametocytes act differently as targets for innate immune responses.
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Affiliation(s)
- Yolanda Corbett
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, via Pascal 36, 20133, Milan, Italy. .,Centro Interuniversitario di Ricerca sulla Malaria-Italian Malaria Network, Milan, Italy.
| | - Silvia Parapini
- Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, Milan, Italy.,Centro Interuniversitario di Ricerca sulla Malaria-Italian Malaria Network, Milan, Italy
| | - Federica Perego
- Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, via Pascal 36, 20133, Milan, Italy
| | - Valeria Messina
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy
| | - Serena Delbue
- Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, via Pascal 36, 20133, Milan, Italy
| | - Paola Misiano
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, via Pascal 36, 20133, Milan, Italy
| | - Mario Falchi
- AIDS-Ricerca e sviluppo, Istituto Superiore di Sanità, Rome, Italy
| | - Francesco Silvestrini
- Dipartimento di Malattie Infettive, Istituto Superiore di Sanità, Rome, Italy.,Centro Interuniversitario di Ricerca sulla Malaria-Italian Malaria Network, Milan, Italy
| | - Donatella Taramelli
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, via Pascal 36, 20133, Milan, Italy.,Centro Interuniversitario di Ricerca sulla Malaria-Italian Malaria Network, Milan, Italy
| | - Nicoletta Basilico
- Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, via Pascal 36, 20133, Milan, Italy.,Centro Interuniversitario di Ricerca sulla Malaria-Italian Malaria Network, Milan, Italy
| | - Sarah D'Alessandro
- Dipartimento di Scienze Biomediche, Chirurgiche e Odontoiatriche, Università degli Studi di Milano, via Pascal 36, 20133, Milan, Italy. .,Centro Interuniversitario di Ricerca sulla Malaria-Italian Malaria Network, Milan, Italy. .,Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, via Pascal 36, 20133, Milan, Italy.
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23
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Patel PN, Tolia N. Structural vaccinology of malaria transmission-blocking vaccines. Expert Rev Vaccines 2021; 20:199-214. [PMID: 33430656 PMCID: PMC11077433 DOI: 10.1080/14760584.2021.1873135] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 12/16/2020] [Indexed: 02/06/2023]
Abstract
Introduction: The development of effective vaccines remains a major health priority to combat the global burden of malaria, a life-threatening disease caused by Plasmodium parasites. Transmission-blocking vaccines (TBVs) elicit antibodies that neutralize the sexual stages of the parasite in blood meals ingested by the Anopheles mosquito, interrupting parasite development in the vector host and preventing disease spread to other individuals.Areas covered: The P. falciparum gametocyte surface antigens Pfs230, Pfs48/45, and Pfs47, the parasite ookinete surface protein Pfs25, and the male gametocyte specific protein PfHAP2 are leading TBV candidates, some of which are in clinical development. The recent expansion of methodology to study monoclonal antibodies isolated directly from humans and animal models, coupled with effective measures for parasite neutralization, has provided unprecedented insight into TBV efficacy and development.Expert opinion: Available structural and functional data on antigen-monoclonal antibody (Ag-mAb) complexes, as well as epitope classification studies, have identified neutralizing epitopes that may aid vaccine development and improve protection. Here, we review the clinical prospects of TBV candidates, progress in the development of novel vaccine strategies for TBVs, and the impact of structural vaccinology in TBV design.
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Affiliation(s)
- Palak N Patel
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Niraj Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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24
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Singh SK, Plieskatt J, Chourasia BK, Fabra-García A, Garcia-Senosiain A, Singh V, Bengtsson KL, Reimer JM, Sauerwein R, Jore MM, Theisen M. A Reproducible and Scalable Process for Manufacturing a Pfs48/45 Based Plasmodium falciparum Transmission-Blocking Vaccine. Front Immunol 2021; 11:606266. [PMID: 33505395 PMCID: PMC7832176 DOI: 10.3389/fimmu.2020.606266] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/20/2020] [Indexed: 11/14/2022] Open
Abstract
The cysteine-rich Pfs48/45 protein, a Plasmodium falciparum sexual stage surface protein, has been advancing as a candidate antigen for a transmission-blocking vaccine (TBV) for malaria. However, Pfs48/45 contains multiple disulfide bonds, that are critical for proper folding and induction of transmission-blocking (TB) antibodies. We have previously shown that R0.6C, a fusion of the 6C domain of Pfs48/45 and a fragment of PfGLURP (R0), expressed in Lactococcus lactis, was properly folded and induced transmission-blocking antibodies. Here we describe the process development and technology transfer of a scalable and reproducible process suitable for R0.6C manufacturing under current Good Manufacturing Practices (cGMP). This process resulted in a final purified yield of 25 mg/L, sufficient for clinical evaluation. A panel of analytical assays for release and stability assessment of R0.6C were developed including HPLC, SDS-PAGE, and immunoblotting with the conformation-dependent TB mAb45.1. Intact mass analysis of R0.6C confirmed the identity of the product including the three disulfide bonds and the absence of post-translational modifications. Multi-Angle Light Scattering (MALS) coupled to size exclusion chromatography (SEC-MALS), further confirmed that R0.6C was monomeric (~70 kDa) in solution. Lastly, preclinical studies demonstrated that the R0.6C Drug Product (adsorbed to Alhydrogel®) elicited functional antibodies in small rodents and that adding Matrix-M™ adjuvant further increased the functional response. Here, building upon our past work, we filled the gap between laboratory and manufacturing to ready R0.6C for production under cGMP and eventual clinical evaluation as a malaria TB vaccine.
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Affiliation(s)
- Susheel K Singh
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Jordan Plieskatt
- PATH's Malaria Vaccine Initiative, Washington, DC, United States
| | - Bishwanath K Chourasia
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Amanda Fabra-García
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Asier Garcia-Senosiain
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Vandana Singh
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Robert Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
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25
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Touray AO, Mobegi VA, Wamunyokoli F, Butungi H, Herren JK. Prevalence of asymptomatic P. falciparum gametocyte carriage in schoolchildren and assessment of the association between gametocyte density, multiplicity of infection and mosquito infection prevalence. Wellcome Open Res 2020; 5:259. [PMID: 33959684 PMCID: PMC8078214 DOI: 10.12688/wellcomeopenres.16299.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/22/2020] [Indexed: 07/22/2023] Open
Abstract
Background: Malaria is a major public health threat in sub-Saharan Africa. Asymptomatic Plasmodium falciparum gametocyte carriers are potential infectious reservoirs for sustaining transmission in many malaria endemic regions. The aim of the study was to assess the prevalence of gametocyte carriage and some of its associated risk factors among asymptomatic schoolchildren in Western Kenya and further analyse the association between gametocyte density, multiplicity of infection (MOI) and mosquito infection prevalence. Methods: Rapid diagnostic tests were used to screen for P. falciparum parasite infection among schoolchildren (5-15 years old) and the results were verified using microscopy. Microscopy positive gametocyte carriers were selected to feed laboratory reared An. gambiae s.l. mosquitoes using membrane feeding method. Genomic DNA was extracted from dry blood spot samples and P. falciparum populations were genotyped using 10 polymorphic microsatellite markers. Assessment of the association between MOI and gametocyte density and mosquito infection prevalence was conducted. Results: A significantly higher prevalence of P. falciparum infection was found in males 31.54% (764/2422) ( p-value < 0.001) compared to females 26.72% (657/2459). The microscopy gametocyte prevalence among the study population was 2% (84/4881). Children aged 5-9 years have a higher prevalence of gametocyte carriage (odds ratios = 2.1 [95% CI = 1.3-3.4], P = 0.002) as compared to children aged 10-15 years. After challenging An. gambiae s.l. by membrane feeding assay on gametocyte positive patient blood, our results indicate that 68.1% of the variation in mosquito infection prevalence is accounted for by gametocyte density and MOI (R-SQR. = 0.681, p < 0.001). Conclusions: Age was a significant risk factor for gametocyte carriage, as indicated by the higher risk of gametocyte carriage among the younger children (5-9 years). Gametocyte density and MOI statistically significantly predicted mosquito infection prevalence. Both of the variables added significantly to the prediction ( p < 0.05).
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Affiliation(s)
- Abdoulie O. Touray
- Department of Molecular Biology and Biotechnology, Institute of Basic Sciences, Technology and Innovation, Pan African University (PAUSTI), Nairobi, Kenya
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Victor A. Mobegi
- Department of Biochemistry, School of Medicine, University of Nairobi, Nairobi, Kenya
| | - Fred Wamunyokoli
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology (JKUAT), Nairobi, Kenya
| | - Hellen Butungi
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Wits Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witswatersrand, Johannesburg, South Africa
| | - Jeremy K. Herren
- International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
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26
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de Jong RM, Tebeje SK, Meerstein‐Kessel L, Tadesse FG, Jore MM, Stone W, Bousema T. Immunity against sexual stage Plasmodium falciparum and Plasmodium vivax parasites. Immunol Rev 2020; 293:190-215. [PMID: 31840844 PMCID: PMC6973022 DOI: 10.1111/imr.12828] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/30/2019] [Accepted: 11/14/2019] [Indexed: 12/25/2022]
Abstract
The efficient spread of malaria from infected humans to mosquitoes is a major challenge for malaria elimination initiatives. Gametocytes are the only Plasmodium life stage infectious to mosquitoes. Here, we summarize evidence for naturally acquired anti-gametocyte immunity and the current state of transmission blocking vaccines (TBV). Although gametocytes are intra-erythrocytic when present in infected humans, developing Plasmodium falciparum gametocytes may express proteins on the surface of red blood cells that elicit immune responses in naturally exposed individuals. This immune response may reduce the burden of circulating gametocytes. For both P. falciparum and Plasmodium vivax, there is a solid evidence that antibodies against antigens present on the gametocyte surface, when co-ingested with gametocytes, can influence transmission to mosquitoes. Transmission reducing immunity, reducing the burden of infection in mosquitoes, is a well-acknowledged but poorly quantified phenomenon that forms the basis for the development of TBV. Transmission enhancing immunity, increasing the likelihood or intensity of transmission to mosquitoes, is more speculative in nature but is convincingly demonstrated for P. vivax. With the increased interest in malaria elimination, TBV and monoclonal antibodies have moved to the center stage of malaria vaccine development. Methodologies to prioritize and evaluate products are urgently needed.
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MESH Headings
- Antibodies, Blocking/immunology
- Antibodies, Protozoan/immunology
- Host-Parasite Interactions/immunology
- Humans
- Immunity
- Immunomodulation
- Life Cycle Stages
- Malaria Vaccines/immunology
- Malaria, Falciparum/immunology
- Malaria, Falciparum/parasitology
- Malaria, Falciparum/prevention & control
- Malaria, Falciparum/transmission
- Malaria, Vivax/immunology
- Malaria, Vivax/parasitology
- Malaria, Vivax/prevention & control
- Malaria, Vivax/transmission
- Plasmodium falciparum/growth & development
- Plasmodium falciparum/immunology
- Plasmodium vivax/growth & development
- Plasmodium vivax/immunology
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Affiliation(s)
- Roos M. de Jong
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | | | - Lisette Meerstein‐Kessel
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Centre for Molecular and Biomolecular InformaticsRadboud Institute for Molecular Life SciencesNijmegenThe Netherlands
| | - Fitsum G. Tadesse
- Armauer Hansen Research InstituteAddis AbabaEthiopia
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Matthijs M. Jore
- Radboud Institute for Molecular Life SciencesRadboud University Medical CenterNijmegenThe Netherlands
| | - Will Stone
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
| | - Teun Bousema
- Radboud Institute for Health SciencesRadboud University Medical CenterNijmegenThe Netherlands
- Department of Immunology and InfectionLondon School of Hygiene and Tropical MedicineLondonUK
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Muthui MK, Kamau A, Bousema T, Blagborough AM, Bejon P, Kapulu MC. Immune Responses to Gametocyte Antigens in a Malaria Endemic Population-The African falciparum Context: A Systematic Review and Meta-Analysis. Front Immunol 2019; 10:2480. [PMID: 31695697 PMCID: PMC6817591 DOI: 10.3389/fimmu.2019.02480] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/04/2019] [Indexed: 11/13/2022] Open
Abstract
Background: Malaria elimination remains a priority research agenda with the need for interventions that reduce and/or block malaria transmission from humans to mosquitoes. Transmission-blocking vaccines (TBVs) are in development, most of which target the transmission stage (i.e., gametocyte) antigens Pfs230 and Pfs48/45. For these interventions to be implemented, there is a need to understand the naturally acquired immunity to gametocytes. Several studies have measured the prevalence of immune responses to Pfs230 and Pfs48/45 in populations in malaria-endemic areas. Methods: We conducted a systematic review of studies carried out in African populations that measured the prevalence of immune responses to the gametocyte antigens Pfs230 and Pfs48/45. We assessed seroprevalence of antibody responses to the two antigens and investigated the effects of covariates such as age, transmission intensity/endemicity, season, and parasite prevalence on the prevalence of these antibody responses by meta-regression. Results: We identified 12 studies covering 23 sites for inclusion in the analysis. We found that the range of reported seroprevalence to Pfs230 and Pfs48/45 varied widely across studies, from 0 to 64% for Pfs48/45 and from 6 to 72% for Pfs230. We also found a modest association between increased age and increased seroprevalence to Pfs230: adults were associated with higher seroprevalence estimates in comparison to children (β coefficient 0.21, 95% CI: 0.05-0.38, p = 0.042). Methodological factors were the most significant contributors to heterogeneity between studies which prevented calculation of pooled prevalence estimates. Conclusions: Naturally acquired sexual stage immunity, as detected by antibodies to Pfs230 and Pfs48/45, was present in most studies analyzed. Significant between-study heterogeneity was seen, and methodological factors were a major contributor to this, and prevented further analysis of epidemiological and biological factors. This demonstrates a need for standardized protocols for conducting and reporting seroepidemiological analyses.
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Affiliation(s)
- Michelle K. Muthui
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
| | - Alice Kamau
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
| | - Teun Bousema
- Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, United Kingdom
- Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Andrew M. Blagborough
- Department of Life Sciences, Imperial College London, London, United Kingdom
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Philip Bejon
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Melissa C. Kapulu
- Department of Biosciences, KEMRI-Wellcome Trust Programme, Kilifi, Kenya
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
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28
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Chan JA, Wetzel D, Reiling L, Miura K, Drew DR, Gilson PR, Anderson DA, Richards JS, Long CA, Suckow M, Jenzelewski V, Tsuboi T, Boyle MJ, Piontek M, Beeson JG. Malaria vaccine candidates displayed on novel virus-like particles are immunogenic and induce transmission-blocking activity. PLoS One 2019; 14:e0221733. [PMID: 31504038 PMCID: PMC6736250 DOI: 10.1371/journal.pone.0221733] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 08/13/2019] [Indexed: 01/23/2023] Open
Abstract
The development of effective malaria vaccines remains a global health priority. Currently, the most advanced vaccine, known as RTS,S, has only shown modest efficacy in clinical trials. Thus, the development of more efficacious vaccines by improving the formulation of RTS,S for increased efficacy or to interrupt malaria transmission are urgently needed. The RTS,S vaccine is based on the presentation of a fragment of the sporozoite antigen on the surface of virus-like particles (VLPs) based on human hepatitis B virus (HBV). In this study, we have developed and evaluated a novel VLP platform based on duck HBV (known as Metavax) for malaria vaccine development. This platform can incorporate large and complex proteins into VLPs and is produced in a Hansenula cell line compatible with cGMP vaccine production. Here, we have established the expression of leading P. falciparum malaria vaccine candidates as VLPs. This includes Pfs230 and Pfs25, which are candidate transmission-blocking vaccine antigens. We demonstrated that the VLPs effectively induce antibodies to malaria vaccine candidates with minimal induction of antibodies to the duck-HBV scaffold antigen. Antibodies to Pfs230 also recognised native protein on the surface of gametocytes, and antibodies to both Pfs230 and Pfs25 demonstrated transmission-reducing activity in standard membrane feeding assays. These results establish the potential utility of this VLP platform for malaria vaccines, which may be suitable for the development of multi-component vaccines that achieve high vaccine efficacy and transmission-blocking immunity.
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Affiliation(s)
- Jo-Anne Chan
- Burnet Institute, Life Sciences, Melbourne, VIC, Australia
- Department of Immunology, Central Clinical School, Monash University, VIC, Australia
| | - David Wetzel
- ARTES Biotechnology GmbH, Langenfeld, Germany
- Technical University of Dortmund, Laboratory of Plant and Process Design, Dortmund, Germany
| | - Linda Reiling
- Burnet Institute, Life Sciences, Melbourne, VIC, Australia
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rockville, Maryland, United States of America
| | - Damien R. Drew
- Burnet Institute, Life Sciences, Melbourne, VIC, Australia
| | - Paul R. Gilson
- Burnet Institute, Life Sciences, Melbourne, VIC, Australia
| | | | - Jack S. Richards
- Burnet Institute, Life Sciences, Melbourne, VIC, Australia
- Department of Medicine, University of Melbourne, VIC, Australia
| | - Carole A. Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rockville, Maryland, United States of America
| | | | | | - Takafumi Tsuboi
- Proteo-Science Centre, Ehime University, Matsuyama, Ehime, Japan
| | - Michelle J. Boyle
- Immunology Department, QIMR-Berghofer Medical Research Institute, Herston, QLD, Australia
| | | | - James G. Beeson
- Burnet Institute, Life Sciences, Melbourne, VIC, Australia
- Department of Immunology, Central Clinical School, Monash University, VIC, Australia
- Department of Medicine, University of Melbourne, VIC, Australia
- * E-mail:
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29
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Wetzel D, Chan JA, Suckow M, Barbian A, Weniger M, Jenzelewski V, Reiling L, Richards JS, Anderson DA, Kouskousis B, Palmer C, Hanssen E, Schembecker G, Merz J, Beeson JG, Piontek M. Display of malaria transmission-blocking antigens on chimeric duck hepatitis B virus-derived virus-like particles produced in Hansenula polymorpha. PLoS One 2019; 14:e0221394. [PMID: 31483818 PMCID: PMC6726142 DOI: 10.1371/journal.pone.0221394] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 08/07/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Malaria caused by Plasmodium falciparum is one of the major threats to human health globally. Despite huge efforts in malaria control and eradication, highly effective vaccines are urgently needed, including vaccines that can block malaria transmission. Chimeric virus-like particles (VLP) have emerged as a promising strategy to develop new malaria vaccine candidates. METHODS We developed yeast cell lines and processes for the expression of malaria transmission-blocking vaccine candidates Pfs25 and Pfs230 as VLP and VLP were analyzed for purity, size, protein incorporation rate and expression of malaria antigens. RESULTS In this study, a novel platform for the display of Plasmodium falciparum antigens on chimeric VLP is presented. Leading transmission-blocking vaccine candidates Pfs25 and Pfs230 were genetically fused to the small surface protein (dS) of the duck hepatitis B virus (DHBV). The resulting fusion proteins were co-expressed in recombinant Hansenula polymorpha (syn. Pichia angusta, Ogataea polymorpha) strains along with the wild-type dS as the VLP scaffold protein. Through this strategy, chimeric VLP containing Pfs25 or the Pfs230-derived fragments Pfs230c or Pfs230D1M were purified. Up to 100 mg chimeric VLP were isolated from 100 g dry cell weight with a maximum protein purity of 90% on the protein level. Expression of the Pfs230D1M construct was more efficient than Pfs230c and enabled VLP with higher purity. VLP showed reactivity with transmission-blocking antibodies and supported the surface display of the malaria antigens on the native VLP. CONCLUSION The incorporation of leading Plasmodium falciparum transmission-blocking antigens into the dS-based VLP scaffold is a promising novel strategy for their display on nano-scaled particles. Competitive processes for efficient production and purification were established in this study.
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Affiliation(s)
- David Wetzel
- ARTES Biotechnology GmbH, Langenfeld, Germany
- Laboratory of Plant and Process Design, Technical University of Dortmund, Dortmund, Germany
| | - Jo-Anne Chan
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | | | - Andreas Barbian
- Düsseldorf University Hospital, Institute for Anatomy I, Düsseldorf, Germany
| | | | | | - Linda Reiling
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Jack S. Richards
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - David A. Anderson
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Betty Kouskousis
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Catherine Palmer
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Eric Hanssen
- The Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Gerhard Schembecker
- Laboratory of Plant and Process Design, Technical University of Dortmund, Dortmund, Germany
| | - Juliane Merz
- Evonik Technology & Infrastructure GmbH, Hanau, Germany
| | - James G. Beeson
- Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
- Central Clinical School and Department of Microbiology, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia
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30
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Abstract
Malaria vaccine development has rapidly advanced in the past decade. The very first phase 3 clinical trial of the RTS,S vaccine was completed with over 15,000 African infants and children, and pilot implementation studies are underway. Next-generation candidate vaccines using novel antigens, platforms, or approaches targeting different and/or multiple stages of the Plasmodium life cycle are being tested. Many candidates, in various stages of development, promise enhanced efficacy of long duration and broad protection against genetically diverse malaria strains, with a few studies under way in target populations in endemic areas. Malaria vaccines together with other interventions promise interruption and eventual elimination of malaria in endemic areas.
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Affiliation(s)
- Matthew B Laurens
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore 21201, Maryland, USA; .,Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.,Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore 21201, Maryland, USA
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31
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Singh SK, Thrane S, Chourasia BK, Teelen K, Graumans W, Stoter R, van Gemert GJ, van de Vegte-Bolmer MG, Nielsen MA, Salanti A, Sander AF, Sauerwein RW, Jore MM, Theisen M. Pfs230 and Pfs48/45 Fusion Proteins Elicit Strong Transmission-Blocking Antibody Responses Against Plasmodium falciparum. Front Immunol 2019; 10:1256. [PMID: 31231386 PMCID: PMC6560166 DOI: 10.3389/fimmu.2019.01256] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 05/17/2019] [Indexed: 11/13/2022] Open
Abstract
The Plasmodium falciparum Pfs230 and Pfs48/45 proteins are expressed during transmission from man to mosquito and are leading candidates for a malaria transmission blocking vaccine. Individually they generate transmission blocking (TB) antibodies in rodent models. Whether the single protein vaccines are suitable to use in field settings will primarily depend on their potency to elicit functional antibodies. We hypothesized that a combination of both proteins will be more potent than each protein individually. Therefore we designed chimeric proteins composed of fragments of both Pfs230 and Pfs48/45 as well as single protein fragments, and expressed these in Lactoccus lactis. Both the individual Pfs230 and Pfs48/45 fragments and chimeras elicited high levels of functional antibodies in mice. Importantly, one of the chimeric proteins elicited over threefold higher transmission blocking antibody responses than the single antigens alone. Furthermore the immunogenicity of one of the chimeras could be enhanced through coupling to a virus-like particle (VLP). Altogether these data support further clinical development of these novel constructs.
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Affiliation(s)
- Susheel K Singh
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Susan Thrane
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Bishwanath K Chourasia
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Karina Teelen
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Wouter Graumans
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Rianne Stoter
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Morten A Nielsen
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Ali Salanti
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Adam F Sander
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
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32
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Identification of domains within Pfs230 that elicit transmission blocking antibody responses. Vaccine 2019; 37:1799-1806. [PMID: 30824357 PMCID: PMC6708081 DOI: 10.1016/j.vaccine.2019.02.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 01/23/2019] [Accepted: 02/05/2019] [Indexed: 11/23/2022]
Abstract
A transmission-blocking vaccine (TBV) against Plasmodium falciparum is likely to be a valuable tool in a malaria eradication program. Pfs230 is one of the major TBV candidates, and multiple Pfs230-based vaccines induced antibodies, which prevented oocyst formation in mosquitoes as determined by a standard membrane-feeding assay (SMFA). Pfs230 is a >300 kDa protein consisting of 14 cysteine motif (CM) domains, and the size and cysteine-rich nature of the molecule have hampered its production as an intact protein. Except for one early study with maltose-binding protein fusion Pfs230 constructs expressed in Esherichia coli, all other studies have focused on only the first four CM domains in the Pfs230 molecule. To identify all possible TBV candidate domains, we systematically produced either single-CM-domain (a total of 14), 2-CM-domain (7), or 4-CM-domain (6) recombinant protein fragments using a eukaryotic wheat germ cell-free expression system (WGCFS). In addition, two more constructs which covered previously published regions, and an N-terminal prodomain construct spanning the natural cleavage site of Pfs230 were produced. Antisera against each fragment were generated in mice and we evaluated the reactivity to native Pfs230 protein by Western blots and immunofluorescence assay (IFA), and functionality by SMFA. All 30 WGCFS-produced Pfs230 constructs were immunogenic in mice. Approximately half of the mouse antibodies specifically recognized native Pfs230 by Western blots with variable band intensities. Among them, seven antibodies showed higher reactivities against native Pfs230 determined by IFA. Interestingly, antibodies against all protein fragments containing CM domain 1 displayed strong inhibitions in SMFA, while antibodies generated using constructs without CM domain 1 showed no inhibition. The results strongly support the concept that future Pfs230-based vaccine development should focus on the Pfs230 CM domain 1.
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33
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Kengne-Ouafo JA, Sutherland CJ, Binka FN, Awandare GA, Urban BC, Dinko B. Immune Responses to the Sexual Stages of Plasmodium falciparum Parasites. Front Immunol 2019; 10:136. [PMID: 30804940 PMCID: PMC6378314 DOI: 10.3389/fimmu.2019.00136] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 01/16/2019] [Indexed: 11/13/2022] Open
Abstract
Malaria infections remain a serious global health problem in the world, particularly among children and pregnant women in Sub-Saharan Africa. Moreover, malaria control and elimination is hampered by rapid development of resistance by the parasite and the vector to commonly used antimalarial drugs and insecticides, respectively. Therefore, vaccine-based strategies are sorely needed, including those designed to interrupt disease transmission. However, a prerequisite for such a vaccine strategy is the understanding of both the human and vector immune responses to parasite developmental stages involved in parasite transmission in both man and mosquito. Here, we review the naturally acquired humoral and cellular responses to sexual stages of the parasite while in the human host and the Anopheles vector. In addition, updates on current anti-gametocyte, anti-gamete, and anti-mosquito transmission blocking vaccines are given. We conclude with our views on some important future directions of research into P. falciparum sexual stage immunity relevant to the search for the most appropriate transmission-blocking vaccine.
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Affiliation(s)
- Jonas A Kengne-Ouafo
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Colin J Sutherland
- Department of Immunology and Infection, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Fred N Binka
- Department of Epidemiology and Biostatistics, School of Public Health, University of Health and Allied Sciences, Ho, Ghana
| | - Gordon A Awandare
- West African Centre for Cell Biology of Infectious Pathogens, University of Ghana, Accra, Ghana
| | - Britta C Urban
- Faculty of Biological Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Bismarck Dinko
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana
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34
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Wilson KL, Flanagan KL, Prakash MD, Plebanski M. Malaria vaccines in the eradication era: current status and future perspectives. Expert Rev Vaccines 2019; 18:133-151. [PMID: 30601095 DOI: 10.1080/14760584.2019.1561289] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION The challenge to eradicate malaria is an enormous task that will not be achieved by current control measures, thus an efficacious and long-lasting malaria vaccine is required. The licensing of RTS, S/AS01 is a step forward in providing some protection, but a malaria vaccine that protects across multiple transmission seasons is still needed. To achieve this, inducing beneficial immune responses while minimising deleterious non-targeted effects will be essential. AREAS COVERED This article discusses the current challenges and advances in malaria vaccine development and reviews recent human clinical trials for each stage of infection. Pubmed and ScienceDirect were searched, focusing on cell mediated immunity and how T cell subsets might be targeted in future vaccines using novel adjuvants and emerging vaccine technologies. EXPERT COMMENTARY Despite decades of research there is no highly effective licensed malaria vaccine. However, there is cause for optimism as new adjuvants and vaccine systems emerge, and our understanding of correlates of protection increases, especially regarding cellular immunity. The new field of heterologous (non-specific) effects of vaccines also highlights the broader consequences of immunization. Importantly, the WHO led Malaria Vaccine Technology Roadmap illustrates that there is a political will among the global health community to make it happen.
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Affiliation(s)
- K L Wilson
- a Department of Immunology and Pathology, Faculty of Medicine, Nursing and Health Sciences , Monash University , Melbourne , Australia.,b School of Health and Biomedical Sciences , RMIT University , Bundoora , Australia
| | - K L Flanagan
- a Department of Immunology and Pathology, Faculty of Medicine, Nursing and Health Sciences , Monash University , Melbourne , Australia.,b School of Health and Biomedical Sciences , RMIT University , Bundoora , Australia.,c School of Medicine, Faculty of Health Sciences , University of Tasmania , Launceston , Australia
| | - M D Prakash
- b School of Health and Biomedical Sciences , RMIT University , Bundoora , Australia
| | - M Plebanski
- b School of Health and Biomedical Sciences , RMIT University , Bundoora , Australia
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35
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Chan JA, Drew DR, Reiling L, Lisboa-Pinto A, Dinko B, Sutherland CJ, Dent AE, Chelimo K, Kazura JW, Boyle MJ, Beeson JG. Low Levels of Human Antibodies to Gametocyte-Infected Erythrocytes Contrasts the PfEMP1-Dominant Response to Asexual Stages in P. falciparum Malaria. Front Immunol 2019; 9:3126. [PMID: 30692996 PMCID: PMC6340286 DOI: 10.3389/fimmu.2018.03126] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 12/18/2018] [Indexed: 11/13/2022] Open
Abstract
Vaccines that target Plasmodium falciparum gametocytes have the potential to reduce malaria transmission and are thus attractive targets for malaria control. However, very little is known about human immune responses to gametocytes present in human hosts. We evaluated naturally-acquired antibodies to gametocyte-infected erythrocytes (gametocyte-IEs) of different developmental stages compared to other asexual parasite stages among naturally-exposed Kenyan residents. We found that acquired antibodies strongly recognized the surface of mature asexual-IEs, but there was limited reactivity to the surface of gametocyte-IEs of different stages. We used genetically-modified P. falciparum with suppressed expression of PfEMP1, the major surface antigen of asexual-stage IEs, to demonstrate that PfEMP1 is a dominant target of antibodies to asexual-IEs, in contrast to gametocyte-IEs. Antibody reactivity to gametocyte-IEs was similar to asexual-IEs lacking PfEMP1. Significant antibody reactivity to the surface of gametocytes was observed when outside of the host erythrocyte, including recognition of the major gametocyte antigen, Pfs230. This indicates that there is a deficiency of acquired antibodies to gametocyte-IEs despite the acquisition of antibodies to gametocyte antigens and asexual IEs. Our findings suggest that the acquisition of substantial immunity to the surface of gametocyte-IEs is limited, which may facilitate immune evasion to enable malaria transmission even in the face of substantial host immunity to malaria. Further studies are needed to understand the basis for the limited acquisition of antibodies to gametocytes and whether vaccine strategies can generate substantial immunity.
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Affiliation(s)
- Jo-Anne Chan
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - Damien R Drew
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - Linda Reiling
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - Ashley Lisboa-Pinto
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - Bismarck Dinko
- Department of Biomedical Sciences, School of Basic and Biomedical Sciences, University of Health and Allied Sciences, Ho, Ghana
| | - Colin J Sutherland
- Department of Immunology and InfectionLondon School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Arlene E Dent
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, United States
| | - Kiprotich Chelimo
- Department of Biomedical Science and Technology Maseno University, Kisumu, Kenya
| | - James W Kazura
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, United States
| | - Michelle J Boyle
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - James G Beeson
- Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia.,Department of Medicine, University of Melbourne Parkville, VIC, Australia.,Department of Microbiology and Central Clinical School, Monash University Melbourne, VIC, Australia
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36
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Stone W, Bousema T, Sauerwein R, Drakeley C. Two-Faced Immunity? The Evidence for Antibody Enhancement of Malaria Transmission. Trends Parasitol 2018; 35:140-153. [PMID: 30573175 DOI: 10.1016/j.pt.2018.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 11/15/2018] [Accepted: 11/15/2018] [Indexed: 10/27/2022]
Abstract
Plasmodium gametocytes can induce an immune response in humans that interferes with the development of sexual-stage parasites in the mosquito gut. Many early studies of the sexual-stage immune response noted that mosquito infection could be enhanced as well as reduced by immune sera. For Plasmodium falciparum, these reports are scarce, and the phenomenon is generally regarded as a methodological artefact. Plasmodium transmission enhancement (TE) remains contentious, but the clinical development of transmission-blocking vaccines based on sexual-stage antigens requires that it is further studied. In this essay, we review the early literature on the sexual-stage immune response and transmission-modulating immunity. We discuss hypotheses for the mechanism of TE, suggest experiments to prove or disprove its existence, and discuss its possible implications.
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Affiliation(s)
- Will Stone
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK.
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Robert Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, UK
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37
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Pathak AK, Shiau JC, Thomas MB, Murdock CC. Cryogenically preserved RBCs support gametocytogenesis of Plasmodium falciparum in vitro and gametogenesis in mosquitoes. Malar J 2018; 17:457. [PMID: 30522507 PMCID: PMC6282341 DOI: 10.1186/s12936-018-2612-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/01/2018] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND The malaria Eradication Research Agenda (malERA) has identified human-to-mosquito transmission of Plasmodium falciparum as a major target for eradication. The cornerstone for identifying and evaluating transmission in the laboratory is standard membrane feeding assays (SMFAs) where mature gametocytes of P. falciparum generated in vitro are offered to mosquitoes as part of a blood-meal. However, propagation of "infectious" gametocytes requires 10-12 days with considerable physico-chemical demands imposed on host RBCs and thus, "fresh" RBCs that are ≤ 1-week old post-collection are generally recommended. However, in addition to the costs, physico-chemical characteristics unique to RBC donors may confound reproducibility and interpretation of SMFAs. Cryogenic storage of RBCs ("cryo-preserved RBCs") is accepted by European and US FDAs as an alternative to refrigeration (4 °C) for preserving RBC "quality" and while cryo-preserved RBCs have been used for in vitro cultures of other Plasmodia and the asexual stages of P. falciparum, none of the studies required RBCs to support parasite development for > 4 days. RESULTS Using the standard laboratory strain, P. falciparum NF54, 11 SMFAs were performed with RBCs from four separate donors to demonstrate that RBCs cryo-preserved in the gaseous phase of liquid nitrogen (- 196 °C) supported gametocytogenesis in vitro and subsequent gametogenesis in Anopheles stephensi mosquitoes. Overall levels of sporogony in the mosquito, as measured by oocyst and sporozoite prevalence, as well as oocyst burden, from each of the four donors thawed after varying intervals of cryopreservation (1, 4, 8, and 12 weeks) were comparable to using ≤ 1-week old refrigerated RBCs. Lastly, the potential for cryo-preserved RBCs to serve as a suitable alternative substrate is demonstrated for a Cambodian isolate of P. falciparum across two independent SMFAs. CONCLUSIONS Basic guidelines are presented for integrating cryo-preserved RBCs into an existing laboratory/insectary framework for P. falciparum SMFAs with significant potential for reducing running costs while achieving greater reliability. Lastly, scenarios are discussed where cryo-preserved RBCs may be especially useful in enhancing the understanding and/or providing novel insights into the patterns and processes underlying human-to-mosquito transmission.
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Affiliation(s)
- Ashutosh K Pathak
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA.
| | - Justine C Shiau
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA
| | - Matthew B Thomas
- Center for Infectious Disease Dynamics and the Department of Entomology, Pennsylvania State University, State College, PA, 16803, USA
| | - Courtney C Murdock
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, 30602, USA
- Odum School of Ecology, University of Georgia, Athens, GA, 30602, USA
- Center for Ecology of Infectious Diseases, University of Georgia, Athens, GA, 30602, USA
- Center for Tropical Emerging Global Diseases, University of Georgia, Athens, GA, 30602, USA
- Center for Vaccines and Immunology, University of Georgia, Athens, GA, 30602, USA
- Riverbasin Center, University of Georgia, Athens, GA, 30602, USA
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38
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Structural delineation of potent transmission-blocking epitope I on malaria antigen Pfs48/45. Nat Commun 2018; 9:4458. [PMID: 30367064 PMCID: PMC6203815 DOI: 10.1038/s41467-018-06742-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/17/2018] [Indexed: 12/28/2022] Open
Abstract
Interventions that can block the transmission of malaria-causing Plasmodium falciparum (Pf) between the human host and Anopheles vector have the potential to reduce the incidence of malaria. Pfs48/45 is a gametocyte surface protein critical for parasite development and transmission, and its targeting by monoclonal antibody (mAb) 85RF45.1 leads to the potent reduction of parasite transmission. Here, we reveal how the Pfs48/45 6C domain adopts a (SAG1)-related-sequence (SRS) fold. We structurally delineate potent epitope I and show how mAb 85RF45.1 recognizes an electronegative surface with nanomolar affinity. Analysis of Pfs48/45 sequences reveals that polymorphisms are rare for residues involved at the binding interface. Humanization of rat-derived mAb 85RF45.1 conserved the mode of recognition and activity of the parental antibody, while also improving its thermostability. Our work has implications for the development of transmission-blocking interventions, both through improving vaccine designs and the testing of passive delivery of mAbs in humans. Malaria protein Pfs48/45 is a promising transmission-blocking antigen targeted by antibodies. Here, the authors determine the structure of its transmission-blocking epitope I, and generate a humanized monoclonal antibody that binds Pfs48/45 with high affinity.
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39
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Lennartz F, Brod F, Dabbs R, Miura K, Mekhaiel D, Marini A, Jore MM, Søgaard MM, Jørgensen T, de Jongh WA, Sauerwein RW, Long CA, Biswas S, Higgins MK. Structural basis for recognition of the malaria vaccine candidate Pfs48/45 by a transmission blocking antibody. Nat Commun 2018; 9:3822. [PMID: 30237518 PMCID: PMC6148045 DOI: 10.1038/s41467-018-06340-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 08/29/2018] [Indexed: 11/30/2022] Open
Abstract
The quest to develop an effective malaria vaccine remains a major priority in the fight against global infectious disease. An approach with great potential is a transmission-blocking vaccine which induces antibodies that prevent establishment of a productive infection in mosquitos that feed on infected humans, thereby stopping the transmission cycle. One of the most promising targets for such a vaccine is the gamete surface protein, Pfs48/45. Here we establish a system for production of full-length Pfs48/45 and use this to raise a panel of monoclonal antibodies. We map the binding regions of these antibodies on Pfs48/45 and correlate the location of their epitopes with their transmission-blocking activity. Finally, we present the structure of the C-terminal domain of Pfs48/45 bound to the most potent transmission-blocking antibody, and provide key molecular information for future structure-guided immunogen design. Pfs48/45 is a promising component for a transmission-blocking malaria vaccine. Here, the authors develop a system to produce full-length Pfs48/45 for immunisation, characterise a panel of monoclonal antibodies and determine the structure of a potent transmission-blocking epitope.
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Affiliation(s)
- Frank Lennartz
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Florian Brod
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Rebecca Dabbs
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Kazutoyo Miura
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, 20852, MD, USA
| | - David Mekhaiel
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Arianna Marini
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, PO Box 9101, 6500 HB, The Netherlands
| | - Max M Søgaard
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Agern Alle 1, DK-2970, Horsholm, Denmark
| | - Thomas Jørgensen
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Agern Alle 1, DK-2970, Horsholm, Denmark
| | - Willem A de Jongh
- ExpreS2ion Biotechnologies, SCION-DTU Science Park, Agern Alle 1, DK-2970, Horsholm, Denmark
| | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, PO Box 9101, 6500 HB, The Netherlands
| | - Carole A Long
- Malaria Immunology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Rockville, 20852, MD, USA
| | - Sumi Biswas
- Jenner Institute, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, OX3 7DQ, UK.
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
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40
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Ouédraogo AL, Eckhoff PA, Luty AJF, Roeffen W, Sauerwein RW, Bousema T, Wenger EA. Modeling the impact of Plasmodium falciparum sexual stage immunity on the composition and dynamics of the human infectious reservoir for malaria in natural settings. PLoS Pathog 2018; 14:e1007034. [PMID: 29742161 PMCID: PMC5962096 DOI: 10.1371/journal.ppat.1007034] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 05/21/2018] [Accepted: 04/16/2018] [Indexed: 12/22/2022] Open
Abstract
Malaria transmission remains high in Sub-Saharan Africa despite large-scale implementation of malaria control interventions. A comprehensive understanding of the transmissibility of infections to mosquitoes may guide the design of more effective transmission reducing strategies. The impact of P. falciparum sexual stage immunity on the infectious reservoir for malaria has never been studied in natural settings. Repeated measurements were carried out at start-wet, peak-wet and dry season, and provided data on antibody responses against gametocyte/gamete antigens Pfs48/45 and Pfs230 as anti-gametocyte immunity. Data on high and low-density infections and their infectiousness to anopheline mosquitoes were obtained using quantitative molecular methods and mosquito feeding assays, respectively. An event-driven model for P. falciparum sexual stage immunity was developed and fit to data using an agent based malaria model infrastructure. We found that Pfs48/45 and Pfs230 antibody densities increased with increasing concurrent gametocyte densities; associated with 55–70% reduction in oocyst intensity and achieved up to 44% reduction in proportions of infected mosquitoes. We showed that P. falciparum sexual stage immunity significantly reduces transmission of microscopic (p < 0.001) but not submicroscopic (p = 0.937) gametocyte infections to mosquitoes and that incorporating sexual stage immunity into mathematical models had a considerable impact on the contribution of different age groups to the infectious reservoir of malaria. Human antibody responses to gametocyte antigens are likely to be dependent on recent and concurrent high-density gametocyte exposure and have a pronounced impact on the likelihood of onward transmission of microscopic gametocyte densities compared to low density infections. Our mathematical simulations indicate that anti-gametocyte immunity is an important factor for predicting and understanding the composition and dynamics of the human infectious reservoir for malaria. Submicroscopic gametocyte infections are efficiently transmitted from humans to mosquitoes in settings with efficient malaria vectors and may pose challenges for malaria control and elimination efforts. Our understanding of what mechanisms contribute to submicroscopic gametocytes infectiousness remains limited. Here we assess the impact of naturally acquired anti-gametocyte antibodies on malaria transmission to mosquitoes and on the age-dependent composition of the infectious reservoir and seasonal dynamics. Anti-gametocyte immunity significantly reduces the infectiousness of high gametocyte density infections, contributes to explain the age-related profiles of the infectious reservoir in the study area, whilst submicroscopic gametocyte infections that present with lower anti-Pfs48/45 and anti-Pfs230 antibody responses commonly remain transmissible to mosquitoes. Our findings indicate that sexual stage immunity needs to be incorporated in transmission models to better understand transmission dynamics. Furthermore, tools that boost sexual stage immunity may reduce transmission to mosquitoes and thus aid elimination strategies.
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Affiliation(s)
- André Lin Ouédraogo
- Institute for Disease Modeling, Intellectual Ventures, Bellevue, Washington, United States of America
- Département de Sciences Biomédicales, Centre National de Recherche et de Formation sur le Paludisme, Ouagadougou, Burkina Faso
- * E-mail:
| | - Philip A. Eckhoff
- Institute for Disease Modeling, Intellectual Ventures, Bellevue, Washington, United States of America
| | - Adrian J. F. Luty
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, HB, the Netherlands
- MERIT UMR 216/CERPAGE, Institut de Recherche pour le Développement, Cotonou, Bénin
- UMR 216, Mère et enfant face aux infections tropicales, Institut de Recherche pour le Développement, Paris, France
| | - Will Roeffen
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, HB, the Netherlands
| | - Robert W. Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, HB, the Netherlands
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, HB, the Netherlands
| | - Edward A. Wenger
- Institute for Disease Modeling, Intellectual Ventures, Bellevue, Washington, United States of America
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41
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Ippolito MM, Johnson J, Mullin C, Mallow C, Morgan N, Wallender E, Li T, Rosenthal PJ. The Relative Effects of Artemether-lumefantrine and Non-artemisinin Antimalarials on Gametocyte Carriage and Transmission of Plasmodium falciparum: A Systematic Review and Meta-analysis. Clin Infect Dis 2018; 65:486-494. [PMID: 28402391 DOI: 10.1093/cid/cix336] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/07/2017] [Indexed: 11/14/2022] Open
Abstract
Background Artemisinin-based combination therapies (ACTs) have been widely adopted as first-line agents to treat uncomplicated falciparum malaria due to their activity against multidrug resistant parasites. ACTs may also disrupt transmission through a direct antigametocyte effect, but the extent of this effect is uncertain. We assessed the evidence for and estimated the effects of the most widely-deployed ACT, artemether-lumefantrine (AL), relative to non-ACTs on gametocyte clearance and transmission interruption. Methods We searched electronic databases for randomized controlled trials comparing AL to non-ACTs that reported gametocyte counts or results of mosquito-feeding assays. Two authors working independently assessed eligibility, extracted data, and evaluated the risk of bias. We conducted meta-analyses using a random-effects model. Results We identified 22 eligible trials. The pooled odds of gametocytemia at 1 week were lower in AL- compared to non-ACT-treated participants (odds ratio [OR] 0.09; 95% confidence interval [CI], 0.06-0.15; I2 = 0.60, P < .01; 15 trials). The odds of transmission to mosquitoes were also lower in AL treatment groups (OR 0.06; 95% CI, 0.00-0.47, P < .01 at 7 days post-treatment; 1 trial; OR 0.56; 95% CI, 0.36-0.88, P = .01 at 14 days post-treatment; 1 trial). Conclusion AL is superior to non-ACTs in reducing gametocytemia, and, based on limited evidence, abating transmission to mosquitoes. The transmission-limiting benefit of AL has relevance for policymakers planning optimal utilization of control strategies, including use of ACTs for malaria treatment and chemoprevention.
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Affiliation(s)
- Matthew M Ippolito
- Department of Medicine, Johns Hopkins University School of Medicine.,Graduate Training Program in Clinical Investigation, Johns Hopkins University Bloomberg School of Public Health
| | - Julia Johnson
- Graduate Training Program in Clinical Investigation, Johns Hopkins University Bloomberg School of Public Health.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Christopher Mullin
- Department of Medicine, Johns Hopkins University School of Medicine.,Graduate Training Program in Clinical Investigation, Johns Hopkins University Bloomberg School of Public Health
| | - Christopher Mallow
- Department of Medicine, Johns Hopkins University School of Medicine.,Graduate Training Program in Clinical Investigation, Johns Hopkins University Bloomberg School of Public Health
| | - Nadia Morgan
- Department of Medicine, Johns Hopkins University School of Medicine.,Graduate Training Program in Clinical Investigation, Johns Hopkins University Bloomberg School of Public Health
| | - Erika Wallender
- Department of Medicine, University of California San Francisco
| | - Tianjing Li
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
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42
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Koepfli C, Yan G. Plasmodium Gametocytes in Field Studies: Do We Measure Commitment to Transmission or Detectability? Trends Parasitol 2018; 34:378-387. [PMID: 29544966 DOI: 10.1016/j.pt.2018.02.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/07/2018] [Accepted: 02/21/2018] [Indexed: 01/05/2023]
Abstract
The proportion of Plasmodium spp. infections carrying gametocytes, and gametocyte densities, are often reported as surrogate markers for transmission potential. It remains unclear whether parasites under natural conditions adjust commitment to transmission depending on external factors. Population-based surveys comprising mostly asymptomatic low-density infections are always impacted by the sensitivity of the assays used to diagnose infections and detect gametocytes. Asexual parasite density is an important predictor for the probability of detecting gametocytes, and in many cases it can explain patterns in gametocyte carriage without the need for an adjustment of the gametocyte conversion rate. When reporting gametocyte data, quantification of blood-stage parasitemia and its inclusion as a confounder in multivariable analyses is essential.
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Affiliation(s)
- Cristian Koepfli
- Program in Public Health, University of California, Irvine, CA, 92697, USA.
| | - Guiyun Yan
- Program in Public Health, University of California, Irvine, CA, 92697, USA
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43
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Reuling IJ, van de Schans LA, Coffeng LE, Lanke K, Meerstein-Kessel L, Graumans W, van Gemert GJ, Teelen K, Siebelink-Stoter R, van de Vegte-Bolmer M, de Mast Q, van der Ven AJ, Ivinson K, Hermsen CC, de Vlas S, Bradley J, Collins KA, Ockenhouse CF, McCarthy J, Sauerwein RW, Bousema T. A randomized feasibility trial comparing four antimalarial drug regimens to induce Plasmodium falciparum gametocytemia in the controlled human malaria infection model. eLife 2018; 7:e31549. [PMID: 29482720 PMCID: PMC5828662 DOI: 10.7554/elife.31549] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 01/14/2018] [Indexed: 12/16/2022] Open
Abstract
Background Malaria elimination strategies require a thorough understanding of parasite transmission from human to mosquito. A clinical model to induce gametocytes to understand their dynamics and evaluate transmission-blocking interventions (TBI) is currently unavailable. Here, we explore the use of the well-established Controlled Human Malaria Infection model (CHMI) to induce gametocyte carriage with different antimalarial drug regimens. Methods In a single centre, open-label randomised trial, healthy malaria-naive participants (aged 18–35 years) were infected with Plasmodium falciparum by bites of infected Anopheles mosquitoes. Participants were randomly allocated to four different treatment arms (n = 4 per arm) comprising low-dose (LD) piperaquine (PIP) or sulfadoxine-pyrimethamine (SP), followed by a curative regimen upon recrudescence. Male and female gametocyte densities were determined by molecular assays. Results Mature gametocytes were observed in all participants (16/16, 100%). Gametocytes appeared 8.5–12 days after the first detection of asexual parasites. Peak gametocyte densities and gametocyte burden was highest in the LD-PIP/SP arm, and associated with the preceding asexual parasite biomass (p=0.026). Male gametocytes had a mean estimated circulation time of 2.7 days (95% CI 1.5–3.9) compared to 5.1 days (95% CI 4.1–6.1) for female gametocytes. Exploratory mosquito feeding assays showed successful sporadic mosquito infections. There were no serious adverse events or significant differences in the occurrence and severity of adverse events between study arms (p=0.49 and p=0.28). Conclusions The early appearance of gametocytes indicates gametocyte commitment during the first wave of asexual parasites emerging from the liver. Treatment by LD-PIP followed by a curative SP regimen, results in the highest gametocyte densities and the largest number of gametocyte-positive days. This model can be used to evaluate the effect of drugs and vaccines on gametocyte dynamics, and lays the foundation for fulfilling the critical unmet need to evaluate transmission-blocking interventions against falciparum malaria for downstream selection and clinical development. Funding Funded by PATH Malaria Vaccine Initiative (MVI). Clinical trial number NCT02836002.
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Affiliation(s)
- Isaie J Reuling
- Department of Medical MicrobiologyRadboud university medical centerNijmegenNetherlands
| | | | - Luc E Coffeng
- Department of Public HealthErasmus MC, University Medical Center RotterdamRotterdamNetherlands
| | - Kjerstin Lanke
- Department of Medical MicrobiologyRadboud university medical centerNijmegenNetherlands
| | | | - Wouter Graumans
- Department of Medical MicrobiologyRadboud university medical centerNijmegenNetherlands
| | - Geert-Jan van Gemert
- Department of Medical MicrobiologyRadboud university medical centerNijmegenNetherlands
| | - Karina Teelen
- Department of Medical MicrobiologyRadboud university medical centerNijmegenNetherlands
| | | | | | - Quirijn de Mast
- Department of Internal MedicineRadboud University Medical CenterNijmegenNetherlands
| | - André J van der Ven
- Department of Internal MedicineRadboud University Medical CenterNijmegenNetherlands
| | - Karen Ivinson
- PATH Malaria Vaccine InitiativeWashingtonUnited States
| | - Cornelus C Hermsen
- Department of Medical MicrobiologyRadboud university medical centerNijmegenNetherlands
| | - Sake de Vlas
- Department of Public HealthErasmus MC, University Medical Center RotterdamRotterdamNetherlands
| | - John Bradley
- MRC Tropical Epidemiology GroupLondon School of Hygiene and Tropical MedicineLondonUnited Kingdom
| | | | | | - James McCarthy
- Clinical Tropical Medicine LaboratoryQIMR BerghoferBrisbaneAustralia
| | - Robert W Sauerwein
- Department of Medical MicrobiologyRadboud university medical centerNijmegenNetherlands
| | - Teun Bousema
- Department of Medical MicrobiologyRadboud university medical centerNijmegenNetherlands
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44
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Stone WJR, Campo JJ, Ouédraogo AL, Meerstein-Kessel L, Morlais I, Da D, Cohuet A, Nsango S, Sutherland CJ, van de Vegte-Bolmer M, Siebelink-Stoter R, van Gemert GJ, Graumans W, Lanke K, Shandling AD, Pablo JV, Teng AA, Jones S, de Jong RM, Fabra-García A, Bradley J, Roeffen W, Lasonder E, Gremo G, Schwarzer E, Janse CJ, Singh SK, Theisen M, Felgner P, Marti M, Drakeley C, Sauerwein R, Bousema T, Jore MM. Unravelling the immune signature of Plasmodium falciparum transmission-reducing immunity. Nat Commun 2018; 9:558. [PMID: 29422648 PMCID: PMC5805765 DOI: 10.1038/s41467-017-02646-2] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 12/15/2017] [Indexed: 02/02/2023] Open
Abstract
Infection with Plasmodium can elicit antibodies that inhibit parasite survival in the mosquito, when they are ingested in an infectious blood meal. Here, we determine the transmission-reducing activity (TRA) of naturally acquired antibodies from 648 malaria-exposed individuals using lab-based mosquito-feeding assays. Transmission inhibition is significantly associated with antibody responses to Pfs48/45, Pfs230, and to 43 novel gametocyte proteins assessed by protein microarray. In field-based mosquito-feeding assays the likelihood and rate of mosquito infection are significantly lower for individuals reactive to Pfs48/45, Pfs230 or to combinations of the novel TRA-associated proteins. We also show that naturally acquired purified antibodies against key transmission-blocking epitopes of Pfs48/45 and Pfs230 are mechanistically involved in TRA, whereas sera depleted of these antibodies retain high-level, complement-independent TRA. Our analysis demonstrates that host antibody responses to gametocyte proteins are associated with reduced malaria transmission efficiency from humans to mosquitoes.
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Affiliation(s)
- Will J R Stone
- Radboud Institute for Health Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands. .,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | | | | | - Lisette Meerstein-Kessel
- Radboud Institute for Health Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Isabelle Morlais
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP 288, Yaoundé, Cameroon.,Institut de Recherche pour le Développement, MIVEGEC (IRD, CNRS, Univ. Montpellier), 911 Avenue Agropolis, 34394, Montpellier, France
| | - Dari Da
- Institut de Recherche en Sciences de la Santé, 399 Avenue de la Liberté, 01 BP 545, Bobo-Dioulasso, Burkina Faso
| | - Anna Cohuet
- Institut de Recherche pour le Développement, MIVEGEC (IRD, CNRS, Univ. Montpellier), 911 Avenue Agropolis, 34394, Montpellier, France.,Institut de Recherche en Sciences de la Santé, 399 Avenue de la Liberté, 01 BP 545, Bobo-Dioulasso, Burkina Faso
| | - Sandrine Nsango
- Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP 288, Yaoundé, Cameroon.,Faculty of Medecine and Pharmaceutical Science, PO Box 2701, Douala, Cameroon
| | - Colin J Sutherland
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Marga van de Vegte-Bolmer
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Rianne Siebelink-Stoter
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Geert-Jan van Gemert
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Wouter Graumans
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Kjerstin Lanke
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | | | | | - Andy A Teng
- Antigen Discovery Inc., Irvine, CA, 92618, USA
| | - Sophie Jones
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Roos M de Jong
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Amanda Fabra-García
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - John Bradley
- Medical Research Council Tropical Epidemiology Group, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Will Roeffen
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Edwin Lasonder
- School of Biomedical and Healthcare Sciences, Plymouth University, Drakes Circus, Plymouth, PL4 8AA, UK
| | - Giuliana Gremo
- Department of Oncology, University of Torino, Via Santena 5bis, 10126, Torino, Italy
| | - Evelin Schwarzer
- Department of Oncology, University of Torino, Via Santena 5bis, 10126, Torino, Italy
| | - Chris J Janse
- Department of Parasitology, Leiden University Medical Center (LUMC), Albinusdreef 2, 2333 ZA, Leiden, The Netherlands
| | - Susheel K Singh
- Department for Congenital Diseases, Statens Serum Institut, Copenhagen, DK 2300, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, DK 2200, Denmark
| | - Michael Theisen
- Department for Congenital Diseases, Statens Serum Institut, Copenhagen, DK 2300, Denmark.,Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Copenhagen, DK 2200, Denmark
| | - Phil Felgner
- Department of Medicine, University of California Irvine, Irvine, CA, 92697, USA
| | - Matthias Marti
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, 02115, USA.,Wellcome Center for Molecular Parasitology, University of Glasgow, Glasgow, G12 8TA, UK
| | - Chris Drakeley
- Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Robert Sauerwein
- Radboud Institute for Health Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands. .,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Matthijs M Jore
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
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Eldering M, Bompard A, Miura K, Stone W, Morlais I, Cohuet A, van Gemert GJ, Brock PM, Rijpma SR, van de Vegte-Bolmer M, Graumans W, Siebelink-Stoter R, Da DF, Long CA, Morin MJ, Sauerwein RW, Churcher TS, Bousema T. Comparative assessment of An. gambiae and An. stephensi mosquitoes to determine transmission-reducing activity of antibodies against P. falciparum sexual stage antigens. Parasit Vectors 2017; 10:489. [PMID: 29041962 PMCID: PMC5646129 DOI: 10.1186/s13071-017-2414-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 10/01/2017] [Indexed: 01/08/2023] Open
Abstract
Background With the increasing interest in vaccines to interrupt malaria transmission, there is a demand for harmonization of current methods to assess Plasmodium transmission in laboratory settings. Potential vaccine candidates are currently tested in the standard membrane feeding assay (SMFA) that commonly relies on Anopheles stephensi mosquitoes. Other mosquito species including Anopheles gambiae are the dominant malaria vectors for Plasmodium falciparum in sub-Saharan Africa. Methods Using human serum and monoclonal pre-fertilization (anti-Pfs48/45) and post-fertilization (anti-Pfs25) antibodies known to effectively inhibit sporogony, we directly compared SMFA based estimates of transmission-reducing activity (TRA) for An. stephensi and An. gambiae mosquitoes. Results In the absence of transmission-reducing antibodies, average numbers of oocysts were similar between An. gambiae and An. stephensi. Antibody-mediated TRA was strongly correlated between both mosquito species, and absolute TRA estimates for pre-fertilisation monoclonal antibodies (mAb) showed no significant difference between the two species. TRA estimates for IgG of naturally exposed individuals and partially effective concentrations of anti-Pfs25 mAb were higher for An. stephensi than for An. gambiae. Conclusion Our findings support the use of An. stephensi in the SMFA for target prioritization. As a vaccine moves through product development, better estimates of TRA and transmission-blocking activity (TBA) may need to be obtained in epidemiologically relevant parasite-species combination. Electronic supplementary material The online version of this article (10.1186/s13071-017-2414-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maarten Eldering
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Anaïs Bompard
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Kazutoyo Miura
- National Institute of Allergy and Infectious Diseases, Laboratory of Malaria and Vector Research, National Institutes of Health, Rockville, MD, USA
| | - Will Stone
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Isabelle Morlais
- Institut de Recherche pour le Développement, UMR MIVEGEC UM-CNRS 5290-IRD 224, Montpellier, France
| | - Anna Cohuet
- Institut de Recherche pour le Développement, UMR MIVEGEC UM-CNRS 5290-IRD 224, Montpellier, France
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Patrick M Brock
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK.,Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Sanna R Rijpma
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | - Wouter Graumans
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Rianne Siebelink-Stoter
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dari F Da
- Institut de Recherche en Sciences de la Santé, Bobo Dioulasso, Burkina Faso
| | - Carole A Long
- National Institute of Allergy and Infectious Diseases, Laboratory of Malaria and Vector Research, National Institutes of Health, Rockville, MD, USA
| | | | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Thomas S Churcher
- MRC Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands. .,Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK.
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N-Terminal Pfs230 Domain Produced in Baculovirus as a Biological Active Transmission-Blocking Vaccine Candidate. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2017; 24:CVI.00140-17. [PMID: 28747311 PMCID: PMC5629673 DOI: 10.1128/cvi.00140-17] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/23/2017] [Indexed: 12/13/2022]
Abstract
Transmission-blocking vaccines have the potential to accelerate malaria parasite elimination by inducing antibodies that block parasite transmission from humans to mosquitoes. Pfs230, a gametocyte surface protein involved in gamete function, has long been a promising candidate. Due to the large size (3,135 amino acids), complex domains, and repeating 6-cysteine (6-Cys) motifs with a multitude of disulfide bonds, the feasibility of expression of a full-length protein has been difficult. A priority focus, therefore, has been on the generation of single domains, including N-terminal fragments. Here we utilized a heterologous expression system, baculovirus, to produce an N-terminal domain of Pfs230 (Pfs230C1). Pfs230C1 (amino acids 443 to 731) with a polyhistidine affinity tag was expressed in Super Sf9 cells. Since the native host lacks glycosylation machinery, a single N585Q mutation was made to eliminate potential N-linked glycosylation. The expressed protein, purified by nickel affinity, ion exchange, and size exclusion chromatography to >90% purity, was present in monomeric form with an observed mass of 33,510 Da (matching oxidized form). Peptide mapping and disulfide analysis confirmed the proper formation of predicted disulfide bonds. Antibodies, generated against Pfs230C1 in mice, bound to the gametocyte in an immunofluorescence assay (IFA) and demonstrated functional activity in both the standard membrane feeding assay (SMFA) and the exflagellation assay (EXA). The biochemical, biophysical, and immunological results reported herein support the continued advancement of an N-terminal Pfs230 antigen (Pfs230C1) as a component of a transmission-blocking vaccine. Our results also support the continued use of the scalable baculovirus expression system for the generation of complex Plasmodium proteins.
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Concentration of Plasmodium falciparum gametocytes in whole blood samples by magnetic cell sorting enhances parasite infection rates in mosquito feeding assays. Malar J 2017; 16:315. [PMID: 28779750 PMCID: PMC5545093 DOI: 10.1186/s12936-017-1959-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 07/28/2017] [Indexed: 01/07/2023] Open
Abstract
Background Mosquito-feeding assays are important tools to guide the development and support the evaluation of transmission-blocking interventions. These functional bioassays measure the sporogonic development of gametocytes in blood-fed mosquitoes. Measuring the infectivity of low gametocyte densities has become increasingly important in malaria elimination scenarios. This will pose challenges to the sensitivity and throughput of existing mosquito-feeding assay protocols. Here, different gametocyte concentration methods of blood samples were explored to optimize conditions for detection of positive mosquito infections. Methods Mature gametocytes of Plasmodium falciparum were diluted into whole blood samples of malaria-naïve volunteers. Standard centrifugation, Percoll gradient, magnetic cell sorting (MACS) enrichment were compared using starting blood volumes larger than the control (direct) feed. Results MACS gametocyte enrichment resulted in the highest infection intensity with statistically significant increases in mean oocyst density in 2 of 3 experiments (p = 0.0003; p ≤ 0.0001; p = 0.2348). The Percoll gradient and standard centrifugation procedures resulted in variable infectivity. A significant increase in the proportion of infected mosquitoes and oocyst density was found when larger volumes of gametocyte-infected blood were used with the MACS procedure. Conclusions The current study demonstrates that concentration methods of P. falciparum gametocyte-infected whole blood samples can enhance transmission in mosquito-feeding assays. Gametocyte purification by MACS was the most efficient method, allowing the assessment of gametocyte infectivity in low-density gametocyte infections, as can be expected in natural or experimental conditions. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-1959-9) contains supplementary material, which is available to authorized users.
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Gebru T, Ajua A, Theisen M, Esen M, Ngoa UA, Issifou S, Adegnika AA, Kremsner PG, Mordmüller B, Held J. Recognition of Plasmodium falciparum mature gametocyte-infected erythrocytes by antibodies of semi-immune adults and malaria-exposed children from Gabon. Malar J 2017; 16:176. [PMID: 28446190 PMCID: PMC5406886 DOI: 10.1186/s12936-017-1827-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 04/19/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Transmission of malaria from man to mosquito depends on the presence of gametocytes, the sexual stage of Plasmodium parasites in the infected host. Naturally acquired antibodies against gametocytes exist and may play a role in controlling transmission by limiting the gametocyte development in the circulation or by interrupting gamete development and fertilization in the mosquito following ingestion. So far, most studies on antibody responses to sexual stage antigens have focused on a subset of gametocyte-surface antigens, even though inhibitory Ab responses to other gametocyte antigens might also play a role in controlling gametocyte density and fertility. Limited information is available on natural antibody response to the surfaces of gametocyte-infected erythrocytes. METHODS Ab responses to surface antigens of erythrocytes infected by in vitro differentiated Plasmodium falciparum mature gametocytes were investigated in sera of semi-immune adults and malaria-exposed children. In addition, the effect of immunization with GMZ2, a blood stage malaria vaccine candidate, and the effect of intestinal helminth infection on the development of immunity to gametocytes of P. falciparum was evaluated in malaria-exposed children and adults from Gabon. Serum samples from two Phase I clinical trials conducted in Gabon were analysed by microscopic and flow-cytometric immunofluorescence assay. RESULTS Adults had a higher Ab response compared to children. Ab reactivity was significantly higher after fixation and permeabilization of parasitized erythrocytes. Following vaccination with the malaria vaccine candidate GMZ2, anti-gametocyte Ab concentration decreased in adults compared to baseline. Ab response to whole asexual stage antigens had a significant but weak positive correlation to anti-gametocyte Ab responses in adults, but not in children. Children infected with Ascaris lumbricoides had a significantly higher anti-gametocyte Ab response compared to non-infected children. CONCLUSION The current data suggest that antigens exposed on the gametocyte-infected red blood cells are recognized by serum antibodies from malaria-exposed children and semi-immune adults. This anti-gametocyte immune response may be influenced by natural exposure and vaccination. Modulation of the natural immune response to gametocytes by co-infecting parasites should be investigated further and may have an important impact on malaria control strategies.
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Affiliation(s)
- Tamirat Gebru
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,German Centre for Infection Research (DZIF), Partner Site Lambaréné, Gabon.,Department of Medical Laboratory Sciences, College of Medical and Health Sciences, Haramaya University, Harar, Ethiopia
| | - Anthony Ajua
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany
| | - Michael Theisen
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark.,Center for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Meral Esen
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,German Centre for Infection Research (DZIF), Partner Site Lambaréné, Gabon
| | - Ulysse Ateba Ngoa
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,German Centre for Infection Research (DZIF), Partner Site Lambaréné, Gabon.,Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Saadou Issifou
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.,Fondation pour la Recherche Scientifique (FORS), Cotonou, Benin
| | - Ayola A Adegnika
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,German Centre for Infection Research (DZIF), Partner Site Lambaréné, Gabon.,Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands
| | - Peter G Kremsner
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,German Centre for Infection Research (DZIF), Partner Site Lambaréné, Gabon
| | - Benjamin Mordmüller
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany.,German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany.,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon.,German Centre for Infection Research (DZIF), Partner Site Lambaréné, Gabon
| | - Jana Held
- Institute of Tropical Medicine, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany. .,German Centre for Infection Research (DZIF), Partner Site Tübingen, Germany. .,Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon. .,German Centre for Infection Research (DZIF), Partner Site Lambaréné, Gabon.
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Theisen M, Jore MM, Sauerwein R. Towards clinical development of a Pfs48/45-based transmission blocking malaria vaccine. Expert Rev Vaccines 2017; 16:329-336. [PMID: 28043178 DOI: 10.1080/14760584.2017.1276833] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Malaria is a devastating vector-borne disease caused by the Plasmodium parasite, resulting in almost 0.5 million casualties per year. The parasite has a complex life-cycle that includes asexual replication in human red blood cells, causing symptomatic malaria, and sexual stages which are essential for the transmission to the mosquito vector. A vaccine targeting the sexual stages of the parasite and thus blocking transmission will be instrumental for the eradication of malaria. One of the leading transmission blocking vaccine candidates is the sexual stage antigen Pfs48/45. Areas covered: PubMed was searched to review the progress and future prospects for clinical development of a Pfs48/45-based subunit vaccine. We will focus on biological function, naturally acquired immunity, functional activity of specific antibodies, sequence diversity, production of recombinant protein and preclinical studies. Expert commentary: Pfs48/45 is one of the lead-candidates for a transmission blocking vaccine and should be further explored in clinical trials.
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Affiliation(s)
- Michael Theisen
- a Department for Congenital disorders , State Serum Institute , Copenhagen , Denmark.,b Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology , University of Copenhagen , Copenhagen , Denmark.,c Department of Infectious Diseases , Copenhagen University Hospital, Rigshospitalet , Copenhagen , Denmark
| | - Matthijs M Jore
- d Department of Medical Microbiology , Radboud University Medical Center , Nijmegen , The Netherlands
| | - Robert Sauerwein
- d Department of Medical Microbiology , Radboud University Medical Center , Nijmegen , The Netherlands
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