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Ciubotariu II, Broyles BK, Xie S, Thimmapuram J, Mwenda MC, Mambwe B, Mulube C, Matoba J, Schue JL, Moss WJ, Bridges DJ, He Q, Carpi G. Diversity and selection analyses identify transmission-blocking antigens as the optimal vaccine candidates in Plasmodium falciparum. EBioMedicine 2024; 106:105227. [PMID: 39018754 DOI: 10.1016/j.ebiom.2024.105227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Revised: 06/18/2024] [Accepted: 06/18/2024] [Indexed: 07/19/2024] Open
Abstract
BACKGROUND A highly effective vaccine for malaria remains an elusive target, at least in part due to the under-appreciated natural parasite variation. This study aimed to investigate genetic and structural variation, and immune selection of leading malaria vaccine candidates across the Plasmodium falciparum's life cycle. METHODS We analysed 325 P. falciparum whole genome sequences from Zambia, in addition to 791 genomes from five other African countries available in the MalariaGEN Pf3k Database. Ten vaccine antigens spanning three life-history stages were examined for genetic and structural variations, using population genetics measures, haplotype network analysis, and 3D structure selection analysis. FINDINGS Among the ten antigens analysed, only three in the transmission-blocking vaccine category display P. falciparum 3D7 as the dominant haplotype. The antigens AMA1, CSP, MSP119 and CelTOS, are much more diverse than the other antigens, and their epitope regions are under moderate to strong balancing selection. In contrast, Rh5, a blood stage antigen, displays low diversity yet slightly stronger immune selection in the merozoite-blocking epitope region. Except for CelTOS, the transmission-blocking antigens Pfs25, Pfs48/45, Pfs230, Pfs47, and Pfs28 exhibit minimal diversity and no immune selection in epitopes that induce strain-transcending antibodies, suggesting potential effectiveness of 3D7-based vaccines in blocking transmission. INTERPRETATION These findings offer valuable insights into the selection of optimal vaccine candidates against P. falciparum. Based on our results, we recommend prioritising conserved merozoite antigens and transmission-blocking antigens. Combining these antigens in multi-stage approaches may be particularly promising for malaria vaccine development initiatives. FUNDING Purdue Department of Biological Sciences; Puskas Memorial Fellowship; National Institute of Allergy and Infectious Diseases (U19AI089680).
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Affiliation(s)
- Ilinca I Ciubotariu
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Bradley K Broyles
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
| | - Shaojun Xie
- Bioinformatics Core, Purdue University, West Lafayette, IN, USA
| | | | - Mulenga C Mwenda
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | - Brenda Mambwe
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | - Conceptor Mulube
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | | | - Jessica L Schue
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - William J Moss
- The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Qixin He
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA.
| | - Giovanna Carpi
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA; Purdue Institute of Inflammation, Immunology and Infectious Disease, West Lafayette, IN, USA.
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Ciubotariu II, Broyles BK, Xie S, Thimmapuram J, Mwenda MC, Mambwe B, Mulube C, Matoba J, Schue JL, Moss WJ, Bridges DJ, He Q, Carpi G. Diversity and selection analyses identify transmission-blocking antigens as the optimal vaccine candidates in Plasmodium falciparum. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.11.24307175. [PMID: 38766239 PMCID: PMC11100930 DOI: 10.1101/2024.05.11.24307175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Background A highly effective vaccine for malaria remains an elusive target, at least in part due to the under-appreciated natural parasite variation. This study aimed to investigate genetic and structural variation, and immune selection of leading malaria vaccine candidates across the Plasmodium falciparum's life cycle. Methods We analyzed 325 P. falciparum whole genome sequences from Zambia, in addition to 791 genomes from five other African countries available in the MalariaGEN Pf3k Rdatabase. Ten vaccine antigens spanning three life-history stages were examined for genetic and structural variations, using population genetics measures, haplotype network analysis, and 3D structure selection analysis. Findings Among the ten antigens analyzed, only three in the transmission-blocking vaccine category display P. falciparum 3D7 as the dominant haplotype. The antigens AMA1, CSP, MSP119 and CelTOS, are much more diverse than the other antigens, and their epitope regions are under moderate to strong balancing selection. In contrast, Rh5, a blood stage antigen, displays low diversity yet slightly stronger immune selection in the merozoite-blocking epitope region. Except for CelTOS, the transmission-blocking antigens Pfs25, Pfs48/45, Pfs230, Pfs47, and Pfs28 exhibit minimal diversity and no immune selection in epitopes that induce strain-transcending antibodies, suggesting potential effectiveness of 3D7-based vaccines in blocking transmission. Interpretations These findings offer valuable insights into the selection of optimal vaccine candidates against P. falciparum. Based on our results, we recommend prioritizing conserved merozoite antigens and transmission-blocking antigens. Combining these antigens in multi-stage approaches may be particularly promising for malaria vaccine development initiatives. Funding Purdue Department of Biological Sciences; Puskas Memorial Fellowship; National Institute of Allergy and Infectious Diseases (U19AI089680).
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Affiliation(s)
- Ilinca I. Ciubotariu
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Bradley K. Broyles
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Shaojun Xie
- Bioinformatics Core, Purdue University, West Lafayette, Indiana, USA
| | | | - Mulenga C. Mwenda
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | - Brenda Mambwe
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | - Conceptor Mulube
- PATH-Malaria Control and Elimination Partnership in Africa (MACEPA), National Malaria Elimination Centre, Lusaka, Zambia
| | | | - Jessica L. Schue
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - William J. Moss
- The W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | | | - Qixin He
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Giovanna Carpi
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
- Purdue Institute of Inflammation, Immunology and Infectious Disease, West Lafayette, Indiana, USA
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Alkema M, Smit MJ, Marin-Mogollon C, Totté K, Teelen K, van Gemert GJ, van de Vegte-Bolmer M, Mordmüller BG, Reimer JM, Lövgren-Bengtsson KL, Sauerwein RW, Bousema T, Plieskatt J, Theisen M, Jore MM, McCall MBB. A Pfs48/45-based vaccine to block Plasmodium falciparum transmission: phase 1, open-label, clinical trial. BMC Med 2024; 22:170. [PMID: 38649867 PMCID: PMC11036667 DOI: 10.1186/s12916-024-03379-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 04/02/2024] [Indexed: 04/25/2024] Open
Abstract
BACKGROUND The stalling global progress in malaria control highlights the need for novel tools for malaria elimination, including transmission-blocking vaccines. Transmission-blocking vaccines aim to induce human antibodies that block parasite development in the mosquito and mosquitoes becoming infectious. The Pfs48/45 protein is a leading Plasmodium falciparum transmission-blocking vaccine candidate. The R0.6C fusion protein, consisting of Pfs48/45 domain 3 (6C) and the N-terminal region of P. falciparum glutamate-rich protein (R0), has previously been produced in Lactococcus lactis and elicited functional antibodies in rodents. Here, we assess the safety and transmission-reducing efficacy of R0.6C adsorbed to aluminium hydroxide with and without Matrix-M™ adjuvant in humans. METHODS In this first-in-human, open-label clinical trial, malaria-naïve adults, aged 18-55 years, were recruited at the Radboudumc in Nijmegen, the Netherlands. Participants received four intramuscular vaccinations on days 0, 28, 56 and 168 with either 30 µg or 100 µg of R0.6C and were randomised for the allocation of one of the two different adjuvant combinations: aluminium hydroxide alone, or aluminium hydroxide combined with Matrix-M1™ adjuvant. Adverse events were recorded from inclusion until 84 days after the fourth vaccination. Anti-R0.6C and anti-6C IgG titres were measured by enzyme-linked immunosorbent assay. Transmission-reducing activity of participants' serum and purified vaccine-specific immunoglobulin G was assessed by standard membrane feeding assays using laboratory-reared Anopheles stephensi mosquitoes and cultured P. falciparum gametocytes. RESULTS Thirty-one participants completed four vaccinations and were included in the analysis. Administration of all doses was safe and well-tolerated, with one related grade 3 adverse event (transient fever) and no serious adverse events occurring. Anti-R0.6C and anti-6C IgG titres were similar between the 30 and 100 µg R0.6C arms, but higher in Matrix-M1™ arms. Neat participant sera did not induce significant transmission-reducing activity in mosquito feeding experiments, but concentrated vaccine-specific IgGs purified from sera collected two weeks after the fourth vaccination achieved up to 99% transmission-reducing activity. CONCLUSIONS R0.6C/aluminium hydroxide with or without Matrix-M1™ is safe, immunogenic and induces functional Pfs48/45-specific transmission-blocking antibodies, albeit at insufficient serum concentrations to result in transmission reduction by neat serum. Future work should focus on identifying alternative vaccine formulations or regimens that enhance functional antibody responses. TRIAL REGISTRATION The trial is registered with ClinicalTrials.gov under identifier NCT04862416.
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Affiliation(s)
- M Alkema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - M J Smit
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - C Marin-Mogollon
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - K Totté
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - K Teelen
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - G J van Gemert
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - M van de Vegte-Bolmer
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - B G Mordmüller
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | | | | | - R W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
- Present Address: TropIQ Health Sciences, Nijmegen, the Netherlands
| | - T Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - J Plieskatt
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | - M 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
| | - M M Jore
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - M B B McCall
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands.
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Ouologuem DT, Dara A, Kone A, Ouattara A, Djimde AA. Plasmodium falciparum Development from Gametocyte to Oocyst: Insight from Functional Studies. Microorganisms 2023; 11:1966. [PMID: 37630530 PMCID: PMC10460021 DOI: 10.3390/microorganisms11081966] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 07/06/2023] [Accepted: 07/14/2023] [Indexed: 08/27/2023] Open
Abstract
Malaria elimination may never succeed without the implementation of transmission-blocking strategies. The transmission of Plasmodium spp. parasites from the human host to the mosquito vector depends on circulating gametocytes in the peripheral blood of the vertebrate host. Once ingested by the mosquito during blood meals, these sexual forms undergo a series of radical morphological and metabolic changes to survive and progress from the gut to the salivary glands, where they will be waiting to be injected into the vertebrate host. The design of effective transmission-blocking strategies requires a thorough understanding of all the mechanisms that drive the development of gametocytes, gametes, sexual reproduction, and subsequent differentiation within the mosquito. The drastic changes in Plasmodium falciparum shape and function throughout its life cycle rely on the tight regulation of stage-specific gene expression. This review outlines the mechanisms involved in Plasmodium falciparum sexual stage development in both the human and mosquito vector, and zygote to oocyst differentiation. Functional studies unravel mechanisms employed by P. falciparum to orchestrate the expression of stage-specific functional products required to succeed in its complex life cycle, thus providing us with potential targets for developing new therapeutics. These mechanisms are based on studies conducted with various Plasmodium species, including predominantly P. falciparum and the rodent malaria parasites P. berghei. However, the great potential of epigenetics, genomics, transcriptomics, proteomics, and functional genetic studies to improve the understanding of malaria as a disease remains partly untapped because of limitations in studies using human malaria parasites and field isolates.
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Affiliation(s)
- Dinkorma T. Ouologuem
- Malaria Research and Training Center, Faculty of Pharmacy, Faculty of Medicine and Dentistry, University of Sciences, Techniques, and Technologies of Bamako, Bamako 1805, Mali
| | - Antoine Dara
- Malaria Research and Training Center, Faculty of Pharmacy, Faculty of Medicine and Dentistry, University of Sciences, Techniques, and Technologies of Bamako, Bamako 1805, Mali
| | - Aminatou Kone
- Malaria Research and Training Center, Faculty of Pharmacy, Faculty of Medicine and Dentistry, University of Sciences, Techniques, and Technologies of Bamako, Bamako 1805, Mali
| | - Amed Ouattara
- Malaria Research Program, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Abdoulaye A. Djimde
- Malaria Research and Training Center, Faculty of Pharmacy, Faculty of Medicine and Dentistry, University of Sciences, Techniques, and Technologies of Bamako, Bamako 1805, Mali
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Challenger JD, van Beek SW, ter Heine R, van der Boor SC, Charles GD, Smit MJ, Ockenhouse C, Aponte JJ, McCall MBB, Jore MM, Churcher TS, Bousema T. Modeling the Impact of a Highly Potent Plasmodium falciparum Transmission-Blocking Monoclonal Antibody in Areas of Seasonal Malaria Transmission. J Infect Dis 2023; 228:212-223. [PMID: 37042518 PMCID: PMC10345482 DOI: 10.1093/infdis/jiad101] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 02/06/2023] [Accepted: 04/11/2023] [Indexed: 04/13/2023] Open
Abstract
Transmission-blocking interventions can play an important role in combating malaria worldwide. Recently, a highly potent Plasmodium falciparum transmission-blocking monoclonal antibody (TB31F) was demonstrated to be safe and efficacious in malaria-naive volunteers. Here we predict the potential public health impact of large-scale implementation of TB31F alongside existing interventions. We developed a pharmaco-epidemiological model, tailored to 2 settings of differing transmission intensity with already established insecticide-treated nets and seasonal malaria chemoprevention interventions. Community-wide annual administration (at 80% coverage) of TB31F over a 3-year period was predicted to reduce clinical incidence by 54% (381 cases averted per 1000 people per year) in a high-transmission seasonal setting, and 74% (157 cases averted per 1000 people per year) in a low-transmission seasonal setting. Targeting school-aged children gave the largest reduction in terms of cases averted per dose. An annual administration of the transmission-blocking monoclonal antibody TB31F may be an effective intervention against malaria in seasonal malaria settings.
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Affiliation(s)
- Joseph D Challenger
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | | | - Rob ter Heine
- Department of Pharmacy, Radboud Institute for Health Sciences
| | - Saskia C van der Boor
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Giovanni D Charles
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Merel J Smit
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chris Ockenhouse
- PATH Center for Vaccine Innovation and Access, Washington, District of Columbia, USA
| | - John J Aponte
- PATH Center for Vaccine Innovation and Access, Geneva, Switzerland
| | - Matthew B B McCall
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Thomas S Churcher
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
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Mohammed M, Dziedziech A, Sekar V, Ernest M, Alves E Silva TL, Balan B, Emami SN, Biryukova I, Friedländer MR, Jex A, Jacobs-Lorena M, Henriksson J, Vega-Rodriguez J, Ankarklev J. Single-Cell Transcriptomics To Define Plasmodium falciparum Stage Transition in the Mosquito Midgut. Microbiol Spectr 2023; 11:e0367122. [PMID: 36847501 PMCID: PMC10100735 DOI: 10.1128/spectrum.03671-22] [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: 09/12/2022] [Accepted: 02/05/2023] [Indexed: 03/01/2023] Open
Abstract
Malaria inflicts the highest rate of morbidity and mortality among the vector-borne diseases. The dramatic bottleneck of parasite numbers that occurs in the gut of the obligatory mosquito vector provides a promising target for novel control strategies. Using single-cell transcriptomics, we analyzed Plasmodium falciparum development in the mosquito gut, from unfertilized female gametes through the first 20 h after blood feeding, including the zygote and ookinete stages. This study revealed the temporal gene expression of the ApiAP2 family of transcription factors and of parasite stress genes in response to the harsh environment of the mosquito midgut. Further, employing structural protein prediction analyses, we found several upregulated genes predicted to encode intrinsically disordered proteins (IDPs), a category of proteins known for their importance in regulation of transcription, translation, and protein-protein interactions. IDPs are known for their antigenic properties and may serve as suitable targets for antibody- or peptide-based transmission suppression strategies. In total, this study uncovers the P. falciparum transcriptome from early to late parasite development in the mosquito midgut, inside its natural vector, which provides an important resource for future malaria transmission-blocking initiatives. IMPORTANCE The malaria parasite Plasmodium falciparum causes more than half a million deaths per year. The current treatment regimen targets the symptom-causing blood stage inside the human host. However, recent incentives in the field call for novel interventions to block parasite transmission from humans to the mosquito vector. Therefore, we need to better understand the parasite biology during its development inside the mosquito, including a deeper understanding of the expression of genes controlling parasite progression during these stages. Here, we have generated single-cell transcriptome data, covering P. falciparum's development, from gamete to ookinete inside the mosquito midgut, uncovering previously untapped parasite biology, including a repertoire of novel biomarkers to be explored in future transmission-blocking efforts. We anticipate that our study provides an important resource, which can be further explored to improve our understanding of the parasite biology as well as aid in guiding future malaria intervention strategies.
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Affiliation(s)
- Mubasher Mohammed
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Alexis Dziedziech
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Vaishnovi Sekar
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Medard Ernest
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Thiago Luiz Alves E Silva
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Balu Balan
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - S. Noushin Emami
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Inna Biryukova
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Marc R. Friedländer
- Science for Life Laboratory, Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Aaron Jex
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Marcelo Jacobs-Lorena
- Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA
| | - Johan Henriksson
- Laboratory for Molecular Infection Medicine Sweden (MIMS), Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Joel Vega-Rodriguez
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, USA
| | - Johan Ankarklev
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Microbial Single Cell Genomics, Department of Cell and Molecular Biology and Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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Tottey S, Shoji Y, Mark Jones R, Musiychuk K, Chichester JA, Miura K, Zhou L, Lee SM, Plieskatt J, Wu Y, Long CA, Streatfield SJ, Yusibov V. Engineering of a plant-produced virus-like particle to improve the display of the Plasmodium falciparum Pfs25 antigen and transmission-blocking activity of the vaccine candidate. Vaccine 2023; 41:938-944. [PMID: 36585278 PMCID: PMC9888754 DOI: 10.1016/j.vaccine.2022.12.048] [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: 05/02/2022] [Revised: 12/04/2022] [Accepted: 12/19/2022] [Indexed: 12/29/2022]
Abstract
Malaria kills around 409,000 people a year, mostly children under the age of five. Malaria transmission-blocking vaccines work to reduce malaria prevalence in a community and have the potential to be part of a multifaceted approach required to eliminate the parasites causing the disease. Pfs25 is a leading malaria transmission-blocking antigen and has been successfully produced in a plant expression system as both a subunit vaccine and as a virus-like particle. This study demonstrates an improved version of the virus-like particle antigen display molecule by eliminating known protease sites from the prior A85 variant. This re-engineered molecule, termed B29, displays three times the number of Pfs25 antigens per virus-like particle compared to the original Pfs25 virus-like particle. An improved purification scheme was also developed, resulting in a substantially higher yield and improved purity. The molecule was evaluated in a mouse model and found to induce improved transmission-blocking activity at lower doses and longer durations than the original molecule.
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Affiliation(s)
- Stephen Tottey
- Fraunhofer USA Center Mid-Atlantic, Biotechnology Division, 9 Innovation Way, Newark, DE 19711, USA
| | - Yoko Shoji
- Fraunhofer USA Center Mid-Atlantic, Biotechnology Division, 9 Innovation Way, Newark, DE 19711, USA
| | - R Mark Jones
- Fraunhofer USA Center Mid-Atlantic, Biotechnology Division, 9 Innovation Way, Newark, DE 19711, USA
| | - Konstantin Musiychuk
- Fraunhofer USA Center Mid-Atlantic, Biotechnology Division, 9 Innovation Way, Newark, DE 19711, USA
| | - Jessica A Chichester
- Fraunhofer USA Center Mid-Atlantic, Biotechnology Division, 9 Innovation Way, Newark, DE 19711, 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
| | - Luwen Zhou
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Shwu-Maan Lee
- PATH's Malaria Vaccine Initiative, Washington, DC 20001, USA
| | | | - Yimin Wu
- PATH's Malaria Vaccine Initiative, Washington, DC 20001, USA
| | - Carole A Long
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Stephen J Streatfield
- Fraunhofer USA Center Mid-Atlantic, Biotechnology Division, 9 Innovation Way, Newark, DE 19711, USA.
| | - Vidadi Yusibov
- Fraunhofer USA Center Mid-Atlantic, Biotechnology Division, 9 Innovation Way, Newark, DE 19711, USA
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8
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van der Boor SC, Smit MJ, van Beek SW, Ramjith J, Teelen K, van de Vegte-Bolmer M, van Gemert GJ, Pickkers P, Wu Y, Locke E, Lee SM, Aponte J, King CR, Birkett AJ, Miura K, Ayorinde MA, Sauerwein RW, Ter Heine R, Ockenhouse CF, Bousema T, Jore MM, McCall MBB. Safety, tolerability, and Plasmodium falciparum transmission-reducing activity of monoclonal antibody TB31F: a single-centre, open-label, first-in-human, dose-escalation, phase 1 trial in healthy malaria-naive adults. THE LANCET. INFECTIOUS DISEASES 2022; 22:1596-1605. [PMID: 35963275 PMCID: PMC9605874 DOI: 10.1016/s1473-3099(22)00428-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/17/2022] [Accepted: 05/30/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Malaria elimination requires interruption of the highly efficient transmission of Plasmodium parasites by mosquitoes. TB31F is a humanised monoclonal antibody that binds the gamete surface protein Pfs48/45 and inhibits fertilisation, thereby preventing further parasite development in the mosquito midgut and onward transmission. We aimed to evaluate the safety and efficacy of TB31F in malaria-naive participants. METHODS In this open-label, first-in-human, dose-escalation, phase 1 clinical trial, healthy, malaria-naive, adult participants were administered a single intravenous dose of 0·1, 1, 3, or 10 mg/kg TB31F or a subcutaneous dose of 100 mg TB31F, and monitored until day 84 after administration at a single centre in the Netherlands. The primary outcome was the frequency and magnitude of adverse events. Additionally, TB31F serum concentrations were measured by ELISA. Transmission-reducing activity (TRA) of participant sera was assessed by standard membrane feeding assays with Anopheles stephensi mosquitoes and cultured Plasmodium falciparum gametocytes. The trial is registered with Clinicaltrials.gov, NCT04238689. FINDINGS Between Feb 17 and Dec 10, 2020, 25 participants were enrolled and sequentially assigned to each dose (n=5 per group). No serious or severe adverse events occurred. In total, 33 grade 1 and six grade 2 related adverse events occurred in 20 (80%) of 25 participants across all groups. Serum of all participants administered 1 mg/kg, 3 mg/kg, or 10 mg/kg TB31F intravenously had more than 80% TRA for 28 days or more, 56 days or more, and 84 days or more, respectively. The TB31F serum concentration reaching 80% TRA was 2·1 μg/mL (95% CI 1·9-2·3). Extrapolating the duration of TRA from antibody kinetics suggests more than 80% TRA is maintained for 160 days (95% CI 136-193) following a single intravenous 10 mg/kg dose. INTERPRETATION TB31F is a well tolerated and highly potent monoclonal antibody capable of completely blocking transmission of P falciparum parasites from humans to mosquitoes. In areas of seasonal transmission, a single dose might cover an entire malaria season. FUNDING PATH's Malaria Vaccine Initiative.
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Affiliation(s)
- Saskia C van der Boor
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Merel J Smit
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Stijn W van Beek
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Jordache Ramjith
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Department for Health Evidence, Biostatistics Section, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Karina Teelen
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Marga van de Vegte-Bolmer
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Geert-Jan van Gemert
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Peter Pickkers
- Department of Intensive Care, Radboud University Medical Center, Nijmegen, Netherlands
| | - Yimin Wu
- PATH's Malaria Vaccine Initiative, PATH, Seattle, WA, USA
| | - Emily Locke
- PATH's Malaria Vaccine Initiative, PATH, Seattle, WA, USA
| | - Shwu-Maan Lee
- PATH's Malaria Vaccine Initiative, PATH, Seattle, WA, USA
| | - John Aponte
- PATH's Malaria Vaccine Initiative, PATH, Seattle, WA, USA
| | - C Richter King
- PATH's Malaria Vaccine Initiative, PATH, Seattle, WA, USA
| | | | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | | | - Robert W Sauerwein
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands; TropIQ Health Sciences, Nijmegen, Netherlands
| | - Rob Ter Heine
- Department of Pharmacy, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Teun Bousema
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Matthijs M Jore
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Matthew B B McCall
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, Netherlands; Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands; Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany; Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon.
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9
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Kumar S, Valansi C, Haile MT, Li X, Flyak K, Dwivedy A, Abatiyow BA, Leeb AS, Kennedy SY, Camargo NM, Vaughan AM, Brukman NG, Podbilewicz B, Kappe SHI. Malaria parasites utilize two essential plasma membrane fusogens for gamete fertilization. Cell Mol Life Sci 2022; 79:549. [PMID: 36241929 PMCID: PMC9568910 DOI: 10.1007/s00018-022-04583-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 09/28/2022] [Accepted: 10/01/2022] [Indexed: 11/23/2022]
Abstract
Cell fusion of female and male gametes is the climax of sexual reproduction. In many organisms, the Hapless 2 (HAP2) family of proteins play a critical role in gamete fusion. We find that Plasmodium falciparum, the causative agent of human malaria, expresses two HAP2 proteins: PfHAP2 and PfHAP2p. These proteins are present in stage V gametocytes and localize throughout the flagellum of male gametes. Gene deletion analysis and genetic crosses show that PfHAP2 and PfHAP2p individually are essential for male fertility and thereby, parasite transmission to the mosquito. Using a cell fusion assay, we demonstrate that PfHAP2 and PfHAP2p are both authentic plasma membrane fusogens. Our results establish nonredundant essential roles for PfHAP2 and PfHAP2p in mediating gamete fusion in Plasmodium and suggest avenues in the design of novel strategies to prevent malaria parasite transmission from humans to mosquitoes.
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Affiliation(s)
- Sudhir Kumar
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Clari Valansi
- The Technion-Israel Institute of Technology, Haifa, Israel
| | - Meseret T Haile
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Xiaohui Li
- The Technion-Israel Institute of Technology, Haifa, Israel
| | - Kateryna Flyak
- The Technion-Israel Institute of Technology, Haifa, Israel
| | - Abhisek Dwivedy
- Nucleic Acids Programming Laboratory, University of Illinois Urbana Champaign, Urbana, IL, USA
| | - Biley A Abatiyow
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Amanda S Leeb
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Spencer Y Kennedy
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Nelly M Camargo
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Ashley M Vaughan
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA.,Department of Pediatrics, University of Washington, Seattle, USA
| | | | | | - Stefan H I Kappe
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA. .,Department of Pediatrics, University of Washington, Seattle, USA. .,Department of Global Health, University of Washington, Seattle, WA, USA.
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10
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Pathak AK, Shiau JC, Franke-Fayard B, Shollenberger LM, Harn DA, Kyle DE, Murdock CC. Streamlining sporozoite isolation from mosquitoes by leveraging the dynamics of migration to the salivary glands. Malar J 2022; 21:264. [PMID: 36100902 PMCID: PMC9472382 DOI: 10.1186/s12936-022-04270-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 08/12/2022] [Indexed: 12/05/2022] Open
Abstract
Background Sporozoites isolated from the salivary glands of Plasmodium-infected mosquitoes are a prerequisite for several basic and pre-clinical applications. Although salivary glands are pooled to maximize sporozoite recovery, insufficient yields pose logistical and analytical hurdles; thus, predicting yields prior to isolation would be valuable. Preceding oocyst densities in the midgut is an obvious candidate. However, it is unclear whether current understanding of its relationship with sporozoite densities can be used to maximize yields, or whether it can capture the potential density-dependence in rates of sporozoite invasion of the salivary glands. Methods This study presents a retrospective analysis of Anopheles stephensi mosquitoes infected with two strains of the rodent-specific Plasmodium berghei. Mean oocyst densities were estimated in the midguts earlier in the infection (11–15 days post-blood meal), with sporozoites pooled from the salivary glands later in the infection (17–29 days). Generalized linear mixed effects models were used to determine if (1) mean oocyst densities can predict sporozoite yields from pooled salivary glands, (2) whether these densities can capture differences in rates of sporozoite invasion of salivary glands, and (3), if the interaction between oocyst densities and time could be leveraged to boost overall yields. Results The non-linear effect of mean oocyst densities confirmed the role of density-dependent constraints in limiting yields beyond certain oocyst densities. Irrespective of oocyst densities however, the continued invasion of salivary glands by the sporozoites boosted recoveries over time (17–29 days post-blood meal) for either parasite strain. Conclusions Sporozoite invasion of the salivary glands over time can be leveraged to maximize yields for P. berghei. In general, however, invasion of the salivary glands over time is a critical fitness determinant for all Plasmodium species (extrinsic incubation period, EIP). Thus, delaying sporozoite collection could, in principle, substantially reduce dissection effort for any parasite within the genus, with the results also alluding to the potential for changes in sporozoites densities over time to modify infectivity for the next host. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04270-y.
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11
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Fontecha G, Escobar D, Ortiz B, Pinto A. A PCR-RFLP Technique to Assess the Geographic Origin of Plasmodium falciparum Strains in Central America. Trop Med Infect Dis 2022; 7:tropicalmed7080149. [PMID: 35893657 PMCID: PMC9394469 DOI: 10.3390/tropicalmed7080149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/23/2022] [Accepted: 07/25/2022] [Indexed: 11/20/2022] Open
Abstract
The elimination of malaria requires strengthening diagnosis and offering adequate and timely treatment. Imported cases of falciparum malaria represent a major challenge for pre-elimination areas, such as Central America, where chloroquine and primaquine continue to be used as first-line treatment. The pfs47 gene has been previously described as a precise molecular marker to track the geographic origin of the parasite. The aim of this study was to design a simple and low-cost technique using the polymorphic region of pfs47 to assess the geographic origin of P. falciparum strains. A PCR-RFLP technique was developed and evaluated using the MseI enzyme that proved capable of discriminating, with reasonable precision, the geographical origin of the parasites. This method could be used by national surveillance laboratories and malaria elimination programs in countries such as Honduras and Nicaragua in cases of malaria where an origin outside the Central American isthmus is suspected.
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12
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Kar S, Sinha A. Plasmodium vivax Duffy Binding Protein-Based Vaccine: a Distant Dream. Front Cell Infect Microbiol 2022; 12:916702. [PMID: 35909975 PMCID: PMC9325973 DOI: 10.3389/fcimb.2022.916702] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
The neglected but highly prevalent Plasmodium vivax in South-east Asia and South America poses a great challenge, with regards to long-term in-vitro culturing and heavily limited functional assays. Such visible challenges as well as narrowed progress in development of experimental research tools hinders development of new drugs and vaccines. The leading vaccine candidate antigen Plasmodium vivax Duffy Binding Protein (PvDBP), is essential for reticulocyte invasion by binding to its cognate receptor, the Duffy Antigen Receptor for Chemokines (DARC), on the host’s reticulocyte surface. Despite its highly polymorphic nature, the amino-terminal cysteine-rich region II of PvDBP (PvDBPII) has been considered as an attractive target for vaccine-mediated immunity and has successfully completed the clinical trial Phase 1. Although this molecule is an attractive vaccine candidate against vivax malaria, there is still a question on its viability due to recent findings, suggesting that there are still some aspects which needs to be looked into further. The highly polymorphic nature of PvDBPII and strain-specific immunity due to PvDBPII allelic variation in Bc epitopes may complicate vaccine efficacy. Emergence of various blood-stage antigens, such as PvRBP, PvEBP and supposedly many more might stand in the way of attaining full protection from PvDBPII. As a result, there is an urgent need to assess and re-assess various caveats connected to PvDBP, which might help in designing a long-term promising vaccine for P. vivax malaria. This review mainly deals with a bunch of rising concerns for validation of DBPII as a vaccine candidate antigen for P. vivax malaria.
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13
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Ramjith J, Alkema M, Bradley J, Dicko A, Drakeley C, Stone W, Bousema T. Quantifying Reductions in Plasmodium falciparum Infectivity to Mosquitos: A Sample Size Calculator to Inform Clinical Trials on Transmission-Reducing Interventions. Front Immunol 2022; 13:899615. [PMID: 35720362 PMCID: PMC9205189 DOI: 10.3389/fimmu.2022.899615] [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: 03/18/2022] [Accepted: 05/10/2022] [Indexed: 11/13/2022] Open
Abstract
Malaria transmission depends on the presence of mature Plasmodium transmission stages (gametocytes) that may render blood-feeding Anopheles mosquitos infectious. Transmission-blocking antimalarial drugs and vaccines can prevent transmission by reducing gametocyte densities or infectivity to mosquitos. Mosquito infection outcomes are thereby informative biological endpoints of clinical trials with transmission blocking interventions. Nevertheless, trials are often primarily designed to determine intervention safety; transmission blocking efficacy is difficult to incorporate in sample size considerations due to variation in infection outcomes and considerable inter-study variation. Here, we use clinical trial data from studies in malaria naive and naturally exposed study participants to present an online sample size calculator tool. This sample size calculator allows studies to be powered to detect reductions in the proportion of infected mosquitos or infection burden (oocyst density) in mosquitos. The utility of this online tool is illustrated using trial data with transmission blocking malaria drugs.
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Affiliation(s)
- Jordache Ramjith
- Radboud Institute for Molecular Life Sciences, Department of Medical Microbiology, Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
- Department for Health Evidence, Biostatistics Research Group, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Manon Alkema
- Radboud Institute for Molecular Life Sciences, Department of Medical Microbiology, Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
| | - John Bradley
- Medical Research Council (MRC) International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alassane Dicko
- Malaria Research and Training Centre, Faculty of Pharmacy and Faculty of Medicine and Dentistry, University of Science, Techniques and Technologies of Bamako, Bamako, Mali
| | - Chris Drakeley
- Medical Research Council (MRC) International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Will Stone
- Medical Research Council (MRC) International Statistics and Epidemiology Group, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Teun Bousema
- Radboud Institute for Molecular Life Sciences, Department of Medical Microbiology, Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, Netherlands
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14
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Wang PP, Jiang X, Bai J, Yang F, Yu X, Wu Y, Zheng W, Zhang Y, Cui L, Liu F, Zhu X, Cao Y. Characterization of PSOP26 as an ookinete surface antigen with improved transmission-blocking activity when fused with PSOP25. Parasit Vectors 2022; 15:175. [PMID: 35606790 PMCID: PMC9125894 DOI: 10.1186/s13071-022-05294-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 04/18/2022] [Indexed: 11/26/2022] Open
Abstract
Background The Plasmodium zygote-to-ookinete developmental transition is an essential step for establishing an infection in the mosquito vector, and antigens expressed during this stage are potential targets for transmission-blocking vaccines (TBVs). The secreted ookinete protein 26 (PSOP26) is a newly identified ookinete surface protein. The anti-PSOP26 serum has moderate transmission-blocking activity, indicating the benefit of further investigating this protein as a target for TBVs. Methods The function of psop26 was analyzed by targeted gene disruption. A chimeric PSOP25-PSOP26 protein was expressed in the Escherichia coli system. The PSOP25-PSOP26 fusion protein, along with mixed (PSOP25 + PSOP26) or single proteins (PSOP26 or PSOP25), were used for the immunization of mice. The antibody titers and immunogenicity of individual sera were analyzed by enzyme-linked immunoassay (ELISA), indirect immunofluorescence assay (IFA), and Western blot. The transmission-blocking activity of sera from different immunization schemes was assessed using in vitro and in vivo assays. Results PSOP26 is a surface protein expressed in Plasmodium gametes and ookinetes. The protein is dispensable for asexual blood-stage development, gametogenesis, and zygote formation, but is essential for the zygote-to-ookinete developmental transition. Specifically, both the prevalence of infections and oocyst densities were decreased in mosquitoes fed on psop26-null mutants. Mixtures of individual PSOP25 and PSOP26 fragments (PSOP25 + PSOP26), as well as chimeras (PSOP25-PSOP26), elicited high antibody levels in mice, with no immunological interference. Antisera against the mixed and fusion proteins elicited higher transmission-reducing activity (TRA) than antisera against the single PSOP26 antigen, but comparable to antisera against PSOP25 antigen alone. Conclusions PSOP26 plays a critical role in the zygote-to-ookinete developmental transition. PSOP25 is a promising TBV candidate that could be used alone to target the ookinete stage. Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05294-8.
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Affiliation(s)
- Peng-Peng Wang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.,Department of Laboratory Medicine, Shengjing Hospital of China Medical University, Shenyang, 110004, China
| | - Xuefeng Jiang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Jie Bai
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Fan Yang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Xinxin Yu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Yudi Wu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Wenqi Zheng
- Department of Clinical Laboratory, Affiliated Hospital of Inner Mongolian Medical University, Inner Mongolia, Huhhot, 150000, China
| | - Yongzhe Zhang
- Department of Pathogen Biology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.,Department of Nephrology, Shengjing Hospital of China Medical University, Shenyang, 110004, Liaoning, China
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612-9415, USA
| | - Fei Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
| | - Xiaotong Zhu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
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15
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Yu S, Wang J, Luo X, Zheng H, Wang L, Yang X, Wang Y. Transmission-Blocking Strategies Against Malaria Parasites During Their Mosquito Stages. Front Cell Infect Microbiol 2022; 12:820650. [PMID: 35252033 PMCID: PMC8889032 DOI: 10.3389/fcimb.2022.820650] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 01/31/2022] [Indexed: 11/24/2022] Open
Abstract
Malaria is still the most widespread parasitic disease and causes the most infections globally. Owing to improvements in sanitary conditions and various intervention measures, including the use of antimalarial drugs, the malaria epidemic in many regions of the world has improved significantly in the past 10 years. However, people living in certain underdeveloped areas are still under threat. Even in some well-controlled areas, the decline in malaria infection rates has stagnated or the rates have rebounded because of the emergence and spread of drug-resistant malaria parasites. Thus, new malaria control methods must be developed. As the spread of the Plasmodium parasite is dependent on the part of its life cycle that occurs in mosquitoes, to eliminate the possibility of malaria infections, transmission-blocking strategies against the mosquito stage should be the first choice. In fact, after the gametocyte enters the mosquito body, it undergoes a series of transformation processes over a short period, thus providing numerous potential blocking targets. Many research groups have carried out studies based on targeting the blocking of transmission during the mosquito phase and have achieved excellent results. Meanwhile, the direct killing of mosquitoes could also significantly reduce the probability of malaria infections. Microorganisms that display complex interactions with Plasmodium, such as Wolbachia and gut flora, have shown observable transmission-blocking potential. These could be used as a biological control strategy and play an important part in blocking the transmission of malaria.
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Affiliation(s)
- Shasha Yu
- Department of Tropical Medicine, College of Military Preventive Medicine, Army Medical University, Chongqing, China
| | - Jing Wang
- Department of Tropical Medicine, College of Military Preventive Medicine, Army Medical University, Chongqing, China
| | - Xue Luo
- Department of Tropical Medicine, College of Military Preventive Medicine, Army Medical University, Chongqing, China
| | - Hong Zheng
- Department of Thoracic Surgery, Xinqiao Hospital, Army Medical University, Chongqing, China
| | - Luhan Wang
- Department of Tropical Medicine, College of Military Preventive Medicine, Army Medical University, Chongqing, China
| | - Xuesen Yang
- Department of Tropical Medicine, College of Military Preventive Medicine, Army Medical University, Chongqing, China
| | - Ying Wang
- Department of Tropical Medicine, College of Military Preventive Medicine, Army Medical University, Chongqing, China
- *Correspondence: Ying Wang,
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16
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Timinao L, Vinit R, Katusele M, Koleala T, Nate E, Czeher C, Burkot TR, Schofield L, Felger I, Mueller I, Laman M, Robinson LJ, Karl S. Infectivity of Symptomatic Malaria Patients to Anopheles farauti Colony Mosquitoes in Papua New Guinea. Front Cell Infect Microbiol 2022; 11:771233. [PMID: 35004348 PMCID: PMC8729879 DOI: 10.3389/fcimb.2021.771233] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/29/2021] [Indexed: 11/23/2022] Open
Abstract
Plasmodium transmission from humans to mosquitoes is an understudied bottleneck in the transmission of malaria. Direct membrane feeding assays (DMFA) allow detailed malaria transmission studies from humans to mosquitoes. Especially for Plasmodium vivax, which cannot be cultured long-term under laboratory conditions, implementation of DMFAs requires proximity to P. vivax endemic areas. In this study, we investigated the infectivity of symptomatic Plasmodium infections to Anopheles farauti colony mosquitoes in Papua New Guinea (PNG). A total of 182 DMFAs were performed with venous blood collected from rapid diagnostic test (RDT) positive symptomatic malaria patients and subsequently analysed by light microscopy and quantitative real time polymerase chain reaction (qPCR). DMFAs resulted in mosquito infections in 20.9% (38/182) of cases. By light microscopy and qPCR, 10 – 11% of P. falciparum and 32 – 44% of P. vivax positive individuals infected An. farauti. Fifty-eight percent of P. vivax and 15% of P. falciparum gametocytaemic infections infected An farauti.
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Affiliation(s)
- Lincoln Timinao
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.,Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, Australia
| | - Rebecca Vinit
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Michelle Katusele
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Tamarah Koleala
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Elma Nate
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Cyrille Czeher
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Thomas R Burkot
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, Australia
| | - Louis Schofield
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, Australia
| | - Ingrid Felger
- Molecular Diagnostics Unit, Swiss Tropical and Public Health Institute, Basel, Switzerland.,Department Biozentrum, University of Basel, Basel, Switzerland
| | - Ivo Mueller
- Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia.,Malaria Parasites and Hosts Unit, Department of Parasites & Insect Vectors, Institut Pasteur, Paris, France
| | - Moses Laman
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Leanne J Robinson
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.,Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC, Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, VIC, Australia.,Vector-Borne Diseases and Tropical Public Health Division, Burnet Institute, Melbourne, VIC, Australia
| | - Stephan Karl
- Vector-borne Diseases Unit, Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.,Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD, Australia
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17
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Ahmad A, Soumare HM, Camara MM, Jadama L, Gaye PM, Bittaye H, Bradley J, Achan J, Bousema T, D'Alessandro U, Drakeley C, Moreno M. Infectivity of patent Plasmodium falciparum gametocyte carriers to mosquitoes: establishing capacity to investigate the infectious reservoir of malaria in a low-transmission setting in The Gambia. Trans R Soc Trop Med Hyg 2021; 115:1462-1467. [PMID: 34107048 PMCID: PMC8643495 DOI: 10.1093/trstmh/trab087] [Citation(s) in RCA: 3] [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: 11/27/2020] [Revised: 04/30/2021] [Accepted: 05/21/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Understanding the human malaria infectious reservoir is important for elimination initiatives. Here, we implemented mosquito membrane feeding experiments to prepare for larger studies to quantify the transmission potential and relative contribution of the human infectious reservoir. METHODS Patients with clinical malaria attending four health facilities with at least 16 Plasmodium falciparum gametocytes per μL were recruited during the 2018 transmission season. Infectiousness to mosquitoes was assessed by direct membrane feeding assay (DMFA). We compared our results with a Bayesian predictive model to investigate the relationship between infectiousness and gametocyte density and explore the impact of fever on gametocyte infectivity. RESULTS A total of 3177 suspected malaria cases were screened; 43.3% (1376) had microscopically patent P. falciparum parasites and 3.6% (114) of them had gametocytes. Out of 68 DMFAs, 38 (55.9%) resulted in at least one infected mosquito, with a total of 15.4% (1178/7667) of mosquitoes infected with 1-475 oocysts per gut. The relationship between mosquito infection prevalence and gametocytaemia was similar to other African settings and negatively associated with fever (OR: 0.188, 95% CI 0.0603 to 0.585, p=0.0039). CONCLUSIONS Among symptomatic malaria patients, fever is strongly associated with transmission failure. Future studies can use DMFA to better understand the human malaria reservoir in settings of low endemicity in The Gambia and inform malaria elimination initiatives.
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Affiliation(s)
- Abdullahi Ahmad
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, PO Box 273, Banjul, The Gambia
- Global Health Institute, Faculty of Medicine and Health Sciences, University of Antwerp, Doornstraat 331, 2610, Wilrijk, Belgium
| | - Harouna M Soumare
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, PO Box 273, Banjul, The Gambia
| | - Muhammed M Camara
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, PO Box 273, Banjul, The Gambia
| | - Lamin Jadama
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, PO Box 273, Banjul, The Gambia
| | - Pa Modou Gaye
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, PO Box 273, Banjul, The Gambia
| | - Haddy Bittaye
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, PO Box 273, Banjul, The Gambia
| | - John Bradley
- MRC International Statistics and Epidemiology Group, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK
| | - Jane Achan
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, PO Box 273, Banjul, The Gambia
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, 6525 GA, Nijmegen, The Netherlands
| | - Umberto D'Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Atlantic Boulevard, Fajara, PO Box 273, Banjul, The Gambia
| | - Chris Drakeley
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK
| | - Marta Moreno
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, Keppel Street, WC1E 7HT, London, UK
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18
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de Jong RM, Meerstein-Kessel L, Da DF, Nsango S, Challenger JD, van de Vegte-Bolmer M, van Gemert GJ, Duarte E, Teyssier N, Sauerwein RW, Churcher TS, Dabire RK, Morlais I, Locke E, Huynen MA, Bousema T, Jore MM. Monoclonal antibodies block transmission of genetically diverse Plasmodium falciparum strains to mosquitoes. NPJ Vaccines 2021; 6:101. [PMID: 34385463 PMCID: PMC8361195 DOI: 10.1038/s41541-021-00366-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/29/2021] [Indexed: 11/09/2022] Open
Abstract
Malaria parasite transmission to mosquitoes relies on the uptake of sexual stage parasites during a blood meal and subsequent formation of oocysts on the mosquito midgut wall. Transmission-blocking vaccines (TBVs) and monoclonal antibodies (mAbs) target sexual stage antigens to interrupt human-to-mosquito transmission and may form important tools for malaria elimination. Although most epitopes of these antigens are considered highly conserved, little is known about the impact of natural genetic diversity on the functional activity of transmission-blocking antibodies. Here we measured the efficacy of three mAbs against leading TBV candidates (Pfs48/45, Pfs25 and Pfs230) in transmission assays with parasites from naturally infected donors compared to their efficacy against the strain they were raised against (NF54). Transmission-reducing activity (TRA) was measured as reduction in mean oocyst intensity. mAb 45.1 (α-Pfs48/45) and mAb 4B7 (α-Pfs25) reduced transmission of field parasites from almost all donors with IC80 values similar to NF54. Sequencing of oocysts that survived high mAb concentrations did not suggest enrichment of escape genotypes. mAb 2A2 (α-Pfs230) only reduced transmission of parasites from a minority of the donors, suggesting that it targets a non-conserved epitope. Using six laboratory-adapted strains, we revealed that mutations in one Pfs230 domain correlate with mAb gamete surface binding and functional TRA. Our findings demonstrate that, despite the conserved nature of sexual stage antigens, minor sequence variation can significantly impact the efficacy of transmission-blocking mAbs. Since mAb 45.1 shows high potency against genetically diverse strains, our findings support its further clinical development and may inform Pfs48/45 vaccine design.
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Affiliation(s)
- Roos M de Jong
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lisette Meerstein-Kessel
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
- Center for Molecular and Biomolecular Informatics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dari F Da
- Institut de Recherche en Sciences de la Santé, Direction Régionale, Bobo Dioulasso, Burkina Faso
| | - Sandrine Nsango
- Malaria Research Laboratory, OCEAC, Yaoundé, Cameroon
- Faculty of Medicine and Pharmaceutical Sciences, University of Douala, Douala, Cameroon
| | - Joseph D Challenger
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Marga van de Vegte-Bolmer
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Geert-Jan van Gemert
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Elias Duarte
- EPPIcenter Research Program, Division of HIV, ID, and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Noam Teyssier
- EPPIcenter Research Program, Division of HIV, ID, and Global Medicine, Department of Medicine, University of California, San Francisco, CA, USA
| | - Robert W Sauerwein
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands
- TropIQ Health Sciences, Nijmegen, Netherlands
| | - Thomas S Churcher
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, UK
| | - Roch K Dabire
- Institut de Recherche en Sciences de la Santé, Direction Régionale, Bobo Dioulasso, Burkina Faso
| | - Isabelle Morlais
- Malaria Research Laboratory, OCEAC, Yaoundé, Cameroon
- MIVEGEC, Université Montpellier, IRD, CNRS, Montpellier, France
| | - Emily Locke
- PATH's Malaria Vaccine Initiative, Washington, DC, USA
| | - Martijn A Huynen
- Center for Molecular and Biomolecular Informatics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Teun Bousema
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands.
| | - Matthijs M Jore
- Department of Medical Microbiology and Radboud Center for Infectious Diseases, Radboud University Medical Center, Nijmegen, The Netherlands.
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19
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Abstract
Almost 20 years have passed since the first reference genome assemblies were published for Plasmodium falciparum, the deadliest malaria parasite, and Anopheles gambiae, the most important mosquito vector of malaria in sub-Saharan Africa. Reference genomes now exist for all human malaria parasites and nearly half of the ~40 important vectors around the world. As a foundation for genetic diversity studies, these reference genomes have helped advance our understanding of basic disease biology and drug and insecticide resistance, and have informed vaccine development efforts. Population genomic data are increasingly being used to guide our understanding of malaria epidemiology, for example by assessing connectivity between populations and the efficacy of parasite and vector interventions. The potential value of these applications to malaria control strategies, together with the increasing diversity of genomic data types and contexts in which data are being generated, raise both opportunities and challenges in the field. This Review discusses advances in malaria genomics and explores how population genomic data could be harnessed to further support global disease control efforts.
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Affiliation(s)
- Daniel E Neafsey
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, MA, USA.
| | - Aimee R Taylor
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Bronwyn L MacInnis
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, MA, USA.
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20
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Timinao L, Vinit R, Katusele M, Schofield L, Burkot TR, Karl S. Optimization of the feeding rate of Anopheles farauti s.s. colony mosquitoes in direct membrane feeding assays. Parasit Vectors 2021; 14:356. [PMID: 34233734 PMCID: PMC8261992 DOI: 10.1186/s13071-021-04842-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 06/11/2021] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Direct membrane feeding assays (DMFA) are an important tool to study parasite transmission to mosquitoes. Mosquito feeding rates in these artificial systems require optimization, as there are a number of factors that potentially influence the feeding rates and there are no standardized methods that apply to all anopheline species. METHODS A range of parameters prior to and during direct membrane feeding (DMF) were evaluated for their impact on Anopheles farauti sensu stricto feeding rates, including the starving conditions and duration of starving prior to feeding, membrane type, DMF exposure time, mosquito age, feeding in the light versus the dark, blood volume, mosquito density and temperature of water bath. RESULTS The average successful DMFA feeding rate for An. farauti s.s. colony mosquitoes increased from 50 to 85% when assay parameters were varied. Overnight starvation and Baudruche membrane yielded the highest feeding rates but rates were also affected by blood volume in the feeder and the mosquito density in the feeding cups. Availability of water during the pre-feed starvation period did not significantly impact feeding rates, nor did the exposure duration to blood in membrane feeders, the age of mosquitoes (3, 5 and 7 days post-emergence), feeding in the light versus the dark, or the temperature (34 °C, 38 °C, 42 °C and 46 °C) of the water bath. CONCLUSION Optimal feeding conditions in An. farauti s.s. DMFA were to offer 50 female mosquitoes in a cup (with a total surface area of ~ 340 cm2 with 1 mosquito/6.8 cm2) that were starved overnight 350-500 µL of blood (collected in heparin-coated Vacutainer tubes) per feeder in feeders with a surface area ~ 5 cm2 (with a maximum capacity of 1.5 mL of blood) via a Baudruche membrane, for at least 10-20 min.
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Affiliation(s)
- Lincoln Timinao
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4870 Australia
| | - Rebecca Vinit
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Michelle Katusele
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Louis Schofield
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4870 Australia
| | - Thomas R. Burkot
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4870 Australia
| | - Stephan Karl
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Australian Institute of Tropical Health and Medicine, James Cook University, Smithfield, QLD 4870 Australia
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21
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Yang F, Liu F, Yu X, Zheng W, Wu Y, Qiu Y, Jin Y, Cui L, Cao Y. Evaluation of two sexual-stage antigens as bivalent transmission-blocking vaccines in rodent malaria. Parasit Vectors 2021; 14:241. [PMID: 33962671 PMCID: PMC8103607 DOI: 10.1186/s13071-021-04743-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 04/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Transmission-blocking vaccine (TBV) is a promising strategy for malaria elimination. It is hypothesized that mixing or fusing two antigens targeting different stages of sexual development may provide higher transmission-blocking activity than these antigens used individually. METHODS A chimeric protein composed of fragments of Pbg37 and PSOP25 was designed and expressed the recombinant protein in Escherichia coli Rosetta-gami B (DE3). After immunizing mice with individual recombinant proteins Pbg37 and PSOP25, mixed proteins (Pbg37+PSOP25), or the fusion protein (Pbg37-PSOP25), the antibody titers of individual sera were analyzed by ELISA. IFA and Western blot were performed to test the reactivity of the antisera with the native proteins in the parasite. The transmission-blocking activity of the different immunization schemes was assessed using in vitro and in vivo assays. RESULTS When Pbg37 and PSOP25 were co-administered in a mixture or as a fusion protein, they elicited similar antibody responses in mice as single antigens without causing immunological interference with each other. Antibodies against the mixed or fused antigens recognized the target proteins in the gametocyte, gamete, zygote, and ookinete stages. The mixed proteins or the fusion protein induced antibodies with significantly stronger transmission-reducing activities in vitro and in vivo than individual antigens. CONCLUSIONS There was no immunological interference between Pbg37 and PSOP25. The bivalent vaccines, which expand the portion of the sexual development during which the transmission-blocking antibodies act, produced significantly stronger transmission-reducing activities than single antigens. Altogether, these data provide the theoretical basis for the development of combination TBVs targeting different sexual stages.
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Affiliation(s)
- Fan Yang
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Fei Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Xinxin Yu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Wenqi Zheng
- Department of Laboratory Medicine, The Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China
| | - Yudi Wu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China
| | - Yue Qiu
- The First Affiliated Hospital of China Medical University, 155 Nanjing North Street, Heping District, Shenyang, 110001, Liaoning, China
| | - Ying Jin
- Liaoning Research Institute of Family Planning, Shenyang, 110031, China
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, 110122, Liaoning, China.
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22
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Challenger JD, Olivera Mesa D, Da DF, Yerbanga RS, Lefèvre T, Cohuet A, Churcher TS. Predicting the public health impact of a malaria transmission-blocking vaccine. Nat Commun 2021; 12:1494. [PMID: 33686061 PMCID: PMC7940395 DOI: 10.1038/s41467-021-21775-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 02/11/2021] [Indexed: 11/24/2022] Open
Abstract
Transmission-blocking vaccines that interrupt malaria transmission from humans to mosquitoes are being tested in early clinical trials. The activity of such a vaccine is commonly evaluated using membrane-feeding assays. Understanding the field efficacy of such a vaccine requires knowledge of how heavily infected wild, naturally blood-fed mosquitoes are, as this indicates how difficult it will be to block transmission. Here we use data on naturally infected mosquitoes collected in Burkina Faso to translate the laboratory-estimated activity into an estimated activity in the field. A transmission dynamics model is then utilised to predict a transmission-blocking vaccine's public health impact alongside existing interventions. The model suggests that school-aged children are an attractive population to target for vaccination. Benefits of vaccination are distributed across the population, averting the greatest number of cases in younger children. Utilising a transmission-blocking vaccine alongside existing interventions could have a substantial impact against malaria.
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Affiliation(s)
- Joseph D Challenger
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom.
| | - Daniela Olivera Mesa
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | - Dari F Da
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
| | - R Serge Yerbanga
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso
- Institut des Sciences et Techniques, Bobo-Dioulasso, Burkina Faso
| | - Thierry Lefèvre
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France
- Centre de Recherche en Écologie et Évolution de la Santé (CREES), Montpellier, France
| | - Anna Cohuet
- MIVEGEC, University of Montpellier, CNRS, IRD, Montpellier, France
| | - Thomas S Churcher
- Medical Research Council Centre for Global Infections Disease Analysis, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
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23
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Mathematical assessment of the impact of human-antibodies on sporogony during the within-mosquito dynamics of Plasmodium falciparum parasites. J Theor Biol 2020; 515:110562. [PMID: 33359209 DOI: 10.1016/j.jtbi.2020.110562] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 11/25/2020] [Accepted: 12/14/2020] [Indexed: 11/23/2022]
Abstract
We develop and analyze a deterministic ordinary differential equation mathematical model for the within-mosquito dynamics of the Plasmodium falciparum malaria parasite. Our model takes into account the action and effect of blood resident human-antibodies, ingested by the mosquito during a blood meal from humans, in inhibiting gamete fertilization. The model also captures subsequent developmental processes that lead to the different forms of the parasite within the mosquito. Continuous functions are used to model the switching transition from oocyst to sporozoites as well as human antibody density variations within the mosquito gut are proposed and used. In sum, our model integrates the developmental stages of the parasite within the mosquito such as gametogenesis, fertilization and sporogenesis culminating in the formation of sporozoites. Quantitative and qualitative analyses including a sensitivity analysis for influential parameters are performed. We quantify the average sporozoite load produced at the end of the within-mosquito malaria parasite's developmental stages. Our analysis shows that an increase in the efficiency of the ingested human antibodies in inhibiting fertilization within the mosquito's gut results in lowering the density of oocysts and hence sporozoites that are eventually produced by each mosquito vector. So, it is possible to control and limit oocysts development and hence sporozoites development within a mosquito by boosting the efficiency of antibodies as a pathway to the development of transmission-blocking vaccines which could potentially reduce oocysts prevalence among mosquitoes and hence reduce the transmission potential from mosquitoes to human.
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24
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Yenkoidiok-Douti L, Canepa GE, Barletta ABF, Barillas-Mury C. In vivo Characterization of Plasmodium berghei P47 (Pbs47) as a Malaria Transmission-Blocking Vaccine Target. Front Microbiol 2020; 11:1496. [PMID: 32719666 PMCID: PMC7348136 DOI: 10.3389/fmicb.2020.01496] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/08/2020] [Indexed: 01/08/2023] Open
Abstract
An effective vaccine to reduce malaria transmission is central to control and ultimately achieve disease eradication. Recently, we demonstrated that antibodies targeting the Plasmodium falciparum surface protein P47 (Pfs47) reduce parasite transmission to Anopheles gambiae mosquitoes. Here, Plasmodium berghei (Pb) was used as a model to assess the in vivo efficacy of a P47-targeted transmission blocking vaccine (Pbs47). Mice were immunized following a prime/boost regimen and infected with P. berghei. The effect of immunization on infectivity to mosquitoes was evaluated by direct feeding on P. berghei-infected mice. The key region in Pbs47 where antibody binding confers protection was mapped, and the immunogenicity of this protective antigen was enhanced by conjugation to a virus-like particle. Passive immunization with 100 and 50 μg/mL of anti-Pbs47 IgG reduced oocyst density by 77 and 67%, respectively. Furthermore, affinity purified Pbs47-specific IgG significantly reduced oocyst density by 88 and 77%, respectively at doses as low as 10 and 1 μg/mL. These studies suggest that P47 is a promising transmission blocking target and show that antibodies to the same specific region in Pfs47 and Pbs47 confer protection.
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Affiliation(s)
- Lampouguin Yenkoidiok-Douti
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Rockville, MD, United States
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Gaspar E. Canepa
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Rockville, MD, United States
| | - Ana Beatriz F. Barletta
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Rockville, MD, United States
| | - Carolina Barillas-Mury
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health, Rockville, MD, United States
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25
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Dantzler KW, Ma S, Ngotho P, Stone WJR, Tao D, Rijpma S, De Niz M, Nilsson Bark SK, Jore MM, Raaijmakers TK, Early AM, Ubaida-Mohien C, Lemgruber L, Campo JJ, Teng AA, Le TQ, Walker CL, Hermand P, Deterre P, Davies DH, Felgner P, Morlais I, Wirth DF, Neafsey DE, Dinglasan RR, Laufer M, Huttenhower C, Seydel K, Taylor T, Bousema T, Marti M. Naturally acquired immunity against immature Plasmodium falciparum gametocytes. Sci Transl Med 2020; 11:11/495/eaav3963. [PMID: 31167926 DOI: 10.1126/scitranslmed.aav3963] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 04/05/2019] [Indexed: 12/11/2022]
Abstract
The recent decline in global malaria burden has stimulated efforts toward Plasmodium falciparum elimination. Understanding the biology of malaria transmission stages may provide opportunities to reduce or prevent onward transmission to mosquitoes. Immature P. falciparum transmission stages, termed stages I to IV gametocytes, sequester in human bone marrow before release into the circulation as mature stage V gametocytes. This process likely involves interactions between host receptors and potentially immunogenic adhesins on the infected red blood cell (iRBC) surface. Here, we developed a flow cytometry assay to examine immune recognition of live gametocytes of different developmental stages by naturally exposed Malawians. We identified strong antibody recognition of the earliest immature gametocyte-iRBCs (giRBCs) but not mature stage V giRBCs. Candidate surface antigens (n = 30), most of them shared between asexual- and gametocyte-iRBCs, were identified by mass spectrometry and mouse immunizations, as well as correlations between responses by protein microarray and flow cytometry. Naturally acquired responses to a subset of candidate antigens were associated with reduced asexual and gametocyte density, and plasma samples from malaria-infected individuals were able to induce immune clearance of giRBCs in vitro. Infected RBC surface expression of select candidate antigens was validated using specific antibodies, and genetic analysis revealed a subset with minimal variation across strains. Our data demonstrate that humoral immune responses to immature giRBCs and shared iRBC antigens are naturally acquired after malaria exposure. These humoral immune responses may have consequences for malaria transmission potential by clearing developing gametocytes, which could be leveraged for malaria intervention.
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Affiliation(s)
- Kathleen W Dantzler
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA.,Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Siyuan Ma
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Priscilla Ngotho
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Will J R Stone
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands.,Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Dingyin Tao
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and the Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Sanna Rijpma
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands
| | - Mariana De Niz
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | - Sandra K Nilsson Bark
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Matthijs M Jore
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands
| | - Tonke K Raaijmakers
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands
| | | | | | - Leandro Lemgruber
- Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
| | | | | | | | | | - Patricia Hermand
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), UMR 1135, ERL CNRS 8255, F-75013 Paris, France
| | - Philippe Deterre
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, Centre d'Immunologie et des Maladies Infectieuses (CIMI-Paris), UMR 1135, ERL CNRS 8255, F-75013 Paris, France
| | - D Huw Davies
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine, CA, USA
| | - Phil Felgner
- Division of Infectious Diseases, Department of Medicine, University of California, Irvine, CA, USA
| | - Isabelle Morlais
- UMR MIVEGEC UM1-CNRS 5290-IRD 224, Institut de Recherche pour le Développement, Montpellier Cedex, France
| | - Dyann F Wirth
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Rhoel R Dinglasan
- W. Harry Feinstone Department of Molecular Microbiology and Immunology and the Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Emerging Pathogens Institute, Department of Infectious Diseases and Immunology, University of Florida College of Veterinary Medicine, Gainesville, FL, USA
| | - Miriam Laufer
- Division of Malaria Research, Institute for Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Curtis Huttenhower
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Karl Seydel
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA.,Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Terrie Taylor
- Department of Osteopathic Medical Specialties, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, USA.,Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | - Teun Bousema
- Radboud Institute for Health Sciences, Radboud University Medical Center, Netherlands. .,Immunology and Infection Department, London School of Hygiene and Tropical Medicine, London, UK
| | - Matthias Marti
- Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, USA. .,Wellcome Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, UK
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26
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Qiu Y, Zhao Y, Liu F, Ye B, Zhao Z, Thongpoon S, Roobsoong W, Sattabongkot J, Cui L, Fan Q, Cao Y. Evaluation of Plasmodium vivax HAP2 as a transmission-blocking vaccine candidate. Vaccine 2020; 38:2841-2848. [PMID: 32093983 DOI: 10.1016/j.vaccine.2020.02.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 01/31/2020] [Accepted: 02/05/2020] [Indexed: 12/23/2022]
Abstract
Transmission-blocking vaccine (TBV) is a promising strategy to interfere with the transmission of malaria. To date, only limited TBV candidate antigens have been identified for Plasmodium vivax. HAP2 is a gamete membrane fusion protein, with homology to the class II viral fusion proteins. Herein we reported the characterization of the PvHAP2 for its potential as a TBV candidate for P. vivax. The HAP2/GCS1 domain of PvHAP2 was expressed in the baculovirus expression system and the recombinant protein was used to raise antibodies in rabbits. Indirect immunofluorescence assays showed that anti-PvHAP2 antibodies reacted only with the male gametocytes on blood smears. Direct membrane feeding assays were conducted using four field P. vivax isolates in Anopheles dirus. At a mean infection intensity of 72.4, 70.7, 51.3, and 15.6 oocysts/midgut with the control antibodies, anti-PvHAP2 antibodies significantly reduced the midgut oocyst intensity by 40.3, 44.4, 61.9, and 89.7%. Whereas the anti-PvHAP2 antibodies were not effective in reducing the infection prevalence at higher parasite exposure (51.3-72.4 oocysts/midgut in the control group), the anti-PvHAP2 antibodies reduced infection prevalence by 50% at a low challenge (15.6 oocysts/midgut). Multiple sequence alignment showed 100% identity among these Thai P. vivax isolates, suggesting that polymorphism may not be an impediment for the utilization of PvHAP2 as a TBV antigen. In conclusion, our results suggest that PvHAP2 could serve as a TBV candidate for P. vivax, and further optimization and evaluation are warranted.
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Affiliation(s)
- Yue Qiu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning 110122, China
| | - Yan Zhao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning 110122, China
| | - Fei Liu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning 110122, China
| | - Bo Ye
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Zhenjun Zhao
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Sataporn Thongpoon
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Wanlapa Roobsoong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Thailand
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL 33612, USA
| | - Qi Fan
- Dalian Institute of Biotechnology, Dalian, Liaoning, China
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, Liaoning 110122, China.
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27
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Ararat-Sarria M, Prado CC, Camargo M, Ospina LT, Camargo PA, Curtidor H, Patarroyo MA. Sexual forms obtained in a continuous in vitro cultured Colombian strain of Plasmodium falciparum (FCB2). Malar J 2020; 19:57. [PMID: 32014000 PMCID: PMC6998264 DOI: 10.1186/s12936-020-3142-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 01/25/2020] [Indexed: 12/03/2022] Open
Abstract
Background The epidemiological control of malaria has been hampered by the appearance of parasite resistance to anti-malarial drugs and by the resistance of mosquito vectors to control measures. This has also been associated with weak transmission control, mostly due to poor control of asymptomatic patients associated with host-vector transmission. This highlights the importance of studying the parasite’s sexual forms (gametocytes) which are involved in this phase of the parasite’s life-cycle. Some African and Asian strains of Plasmodium falciparum have been fully characterized regarding sexual forms’ production; however, few Latin-American strains have been so characterized. This study was aimed at characterizing the Colombian FCB2 strain as a gametocyte producer able to infect mosquitoes. Methods Gametocyte production was induced in in vitro cultured P. falciparum FCB2 and 3D7 strains. Pfap2g and Pfs25 gene expression was detected in FCB2 strain gametocyte culture by RT-PCR. Comparative analysis of gametocytes obtained from both strains was made (counts and morphological changes). In vitro zygote formation from FCB2 gametocytes was induced by incubating a gametocyte culture sample at 27 °C for 20 min. A controlled Anopheles albimanus infection was made using an artificial feed system with cultured FCB2 gametocytes (14–15 days old). Mosquito midgut dissection was then carried out for analyzing oocysts. Results The FCB2 strain expressed Pfap2g, Pfs16, Pfg27/25 and Pfs25 sexual differentiation-related genes after in vitro sexual differentiation induction, producing gametocytes that conserved the expected morphological features. The amount of FCB2 gametocytes produced was similar to that from the 3D7 strain. FCB2 gametocytes were differentiated into zygotes and ookinetes after an in vitro low-temperature stimulus and infected An. albimanus mosquitoes, developing to oocyst stage. Conclusions Even with the history of long-term FCB2 strain in vitro culture maintenance, it has retained its sexual differentiation ability. The gametocytes produced here preserved these parasite forms’ usual characteristics and An. albimanus infection capability, thus enabling its use as a tool for studying sexual form biology, An. albimanus infection comparative analysis and anti-malarial drug and vaccine development.
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Affiliation(s)
- Monica Ararat-Sarria
- Receptor-Ligand Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia.,PhD Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Cesar Camilo Prado
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Milena Camargo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Laura Tatiana Ospina
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Paola Andrea Camargo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia
| | - Hernando Curtidor
- Receptor-Ligand Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia.,Animal Science Faculty, Universidad de Ciencias Aplicadas y Ambientales (U.D.C.A), Bogotá, Colombia
| | - Manuel Alfonso Patarroyo
- Molecular Biology and Immunology Department, Fundación Instituto de Inmunología de Colombia (FIDIC), Bogotá, Colombia. .,School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia.
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28
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Angrisano F, Sala KA, Tapanelli S, Christophides GK, Blagborough AM. Male-Specific Protein Disulphide Isomerase Function is Essential for Plasmodium Transmission and a Vulnerable Target for Intervention. Sci Rep 2019; 9:18300. [PMID: 31797966 PMCID: PMC6892906 DOI: 10.1038/s41598-019-54613-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 11/11/2019] [Indexed: 11/10/2022] Open
Abstract
Inhibiting transmission of Plasmodium is an essential strategy in malaria eradication, and the biological process of gamete fusion during fertilization is a proven target for this approach. Lack of knowledge of the mechanisms underlying fertilization have been a hindrance in the development of transmission-blocking interventions. Here we describe a protein disulphide isomerase essential for malarial transmission (PDI-Trans/PBANKA_0820300) to the mosquito. We show that PDI-Trans activity is male-specific, surface-expressed, essential for fertilization/transmission, and exhibits disulphide isomerase activity which is up-regulated post-gamete activation. We demonstrate that PDI-Trans is a viable anti-malarial drug and vaccine target blocking malarial transmission with the use of PDI inhibitor bacitracin (98.21%/92.48% reduction in intensity/prevalence), and anti-PDI-Trans antibodies (66.22%/33.16% reduction in intensity/prevalence). To our knowledge, these results provide the first evidence that PDI function is essential for malarial transmission, and emphasize the potential of anti-PDI agents to act as anti-malarials, facilitating the future development of novel transmission-blocking interventions.
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Affiliation(s)
- Fiona Angrisano
- Division of Microbiology and Parasitology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, United Kingdom
| | - Katarzyna A Sala
- Department of Life Sciences, Imperial College of Science, Technology and Medicine, London, SW7 2AZ, United Kingdom
| | - Sofia Tapanelli
- Department of Life Sciences, Imperial College of Science, Technology and Medicine, London, SW7 2AZ, United Kingdom
| | - George K Christophides
- Department of Life Sciences, Imperial College of Science, Technology and Medicine, London, SW7 2AZ, United Kingdom
| | - Andrew M Blagborough
- Division of Microbiology and Parasitology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, United Kingdom. .,Department of Life Sciences, Imperial College of Science, Technology and Medicine, London, SW7 2AZ, United Kingdom.
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29
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Abstract
The scientific community worldwide has realized that malaria elimination will not be possible without development of safe and effective transmission-blocking interventions. Primaquine, the only WHO recommended transmission-blocking drug, is not extensively utilized because of the toxicity issues in G6PD deficient individuals. Therefore, there is an urgent need to develop novel therapeutic interventions that can target malaria parasites and effectively block transmission. But at first, it is imperative to unravel the existing portfolio of transmission-blocking drugs. This review highlights transmission-blocking potential of current antimalarial drugs and drugs that are in various stages of clinical development. The collective analysis of the relationships between the structure and the activity of transmission-blocking drugs is expected to help in the design of new transmission-blocking antimalarials.
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30
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Antonelli LR, Junqueira C, Vinetz JM, Golenbock DT, Ferreira MU, Gazzinelli RT. The immunology of Plasmodium vivax malaria. Immunol Rev 2019; 293:163-189. [PMID: 31642531 DOI: 10.1111/imr.12816] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 09/10/2019] [Indexed: 12/13/2022]
Abstract
Plasmodium vivax infection, the predominant cause of malaria in Asia and Latin America, affects ~14 million individuals annually, with considerable adverse effects on wellbeing and socioeconomic development. A clinical hallmark of Plasmodium infection, the paroxysm, is driven by pyrogenic cytokines produced during the immune response. Here, we review studies on the role of specific immune cell types, cognate innate immune receptors, and inflammatory cytokines on parasite control and disease symptoms. This review also summarizes studies on recurrent infections in individuals living in endemic regions as well as asymptomatic infections, a serious barrier to eliminating this disease. We propose potential mechanisms behind these repeated and subclinical infections, such as poor induction of immunological memory cells and inefficient T effector cells. We address the role of antibody-mediated resistance to P. vivax infection and discuss current progress in vaccine development. Finally, we review immunoregulatory mechanisms, such as inhibitory receptors, T regulatory cells, and the anti-inflammatory cytokine, IL-10, that antagonizes both innate and acquired immune responses, interfering with the development of protective immunity and parasite clearance. These studies provide new insights for the clinical management of symptomatic as well as asymptomatic individuals and the development of an efficacious vaccine for vivax malaria.
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Affiliation(s)
- Lis R Antonelli
- Instituto de Pesquisas Rene Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
| | - Caroline Junqueira
- Instituto de Pesquisas Rene Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
| | - Joseph M Vinetz
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA
| | - Douglas T Golenbock
- Division of Infectious Disease and immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Marcelo U Ferreira
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Ricardo T Gazzinelli
- Instituto de Pesquisas Rene Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil.,Division of Infectious Disease and immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA.,Plataforma de Medicina Translacional, Fundação Oswaldo Cruz, Ribeirão Preto, Brazil
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31
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Liu F, Liu Q, Yu C, Zhao Y, Wu Y, Min H, Qiu Y, Jin Y, Miao J, Cui L, Cao Y. An MFS-Domain Protein Pb115 Plays a Critical Role in Gamete Fertilization of the Malaria Parasite Plasmodium berghei. Front Microbiol 2019; 10:2193. [PMID: 31616399 PMCID: PMC6764285 DOI: 10.3389/fmicb.2019.02193] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Accepted: 09/06/2019] [Indexed: 12/20/2022] Open
Abstract
Sexual reproduction is an essential process in the Plasmodium life cycle and a vulnerable step for blocking transmission from the human host to mosquitoes. In this study, we characterized the functions of a conserved cell membrane protein P115 in the rodent malaria parasite Plasmodium berghei ANKA. Pb115 was expressed in both asexual stages (schizonts) and sexual stages (gametocytes, gametes, and ookinetes), and was localized on the plasma membrane of gametes and ookinetes. In P. berghei, genetic deletion of Pb115 (Δpb115) did not affect asexual multiplication, nor did it affect gametocyte development or exflagellation of the male gametocytes. However, mosquitoes fed on Δpb115-infected mice showed 74% reduction in the prevalence of infection and 96.5% reduction in oocyst density compared to those fed on wild-type P. berghei-infected mice. The Δpb115 parasites showed significant defects in the interactions between the male and female gametes, and as a result, very few zygotes were formed in ookinete cultures. Cross fertilization with the male-defective Δpbs48/45 line and the female-defective Δpfs47 line further indicated that the fertilization defects of the Δpb115 lines were present in both male and female gametes. We evaluated the transmission-blocking potential of Pb115 by immunization of mice with a recombinant Pb115 fragment. In vivo mosquito feeding assay showed Pb115 immunization conferred modest, but significant transmission reducing activity with 44% reduction in infection prevalence and 39% reduction in oocyst density. Our results described functional characterization of a conserved membrane protein as a fertility factor in Plasmodium and demonstrated transmission-blocking potential of this antigen.
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Affiliation(s)
- Fei Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Qingyang Liu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Chunyun Yu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Yan Zhao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Yudi Wu
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
| | - Hui Min
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Tampa, FL, United States
| | - Yue Qiu
- The First Hospital of China Medical University, Shenyang, China
| | - Ying Jin
- Liaoning Research Institute of Family Planning, Shenyang, China
| | - Jun Miao
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Tampa, FL, United States
| | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, Tampa, FL, United States
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Sciences, China Medical University, Shenyang, China
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32
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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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33
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Chaves LB, Perce-da-Silva DDS, Totino PRR, Riccio EKP, Baptista BDO, de Souza ABL, Rodrigues-da-Silva RN, Machado RLD, de Souza RM, Daniel-Ribeiro CT, Banic DM, Pratt-Riccio LR, Lima-Junior JDC. Plasmodium vivax ookinete surface protein (Pvs25) is highly conserved among field isolates from five different regions of the Brazilian Amazon. INFECTION GENETICS AND EVOLUTION 2019; 73:287-294. [DOI: 10.1016/j.meegid.2019.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 05/03/2019] [Accepted: 05/04/2019] [Indexed: 12/29/2022]
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34
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Julien JP, Wardemann H. Antibodies against Plasmodium falciparum malaria at the molecular level. Nat Rev Immunol 2019; 19:761-775. [DOI: 10.1038/s41577-019-0209-5] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/24/2019] [Indexed: 12/11/2022]
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35
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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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36
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McCaffery JN, Fonseca JA, Singh B, Cabrera-Mora M, Bohannon C, Jacob J, Arévalo-Herrera M, Moreno A. A Multi-Stage Plasmodium vivax Malaria Vaccine Candidate Able to Induce Long-Lived Antibody Responses Against Blood Stage Parasites and Robust Transmission-Blocking Activity. Front Cell Infect Microbiol 2019; 9:135. [PMID: 31119106 PMCID: PMC6504793 DOI: 10.3389/fcimb.2019.00135] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/15/2019] [Indexed: 12/13/2022] Open
Abstract
Malaria control and interventions including long-lasting insecticide-treated nets, indoor residual spraying, and intermittent preventative treatment in pregnancy have resulted in a significant reduction in the number of Plasmodium falciparum cases. Considerable efforts have been devoted to P. falciparum vaccines development with much less to P. vivax. Transmission-blocking vaccines, which can elicit antibodies targeting Plasmodium antigens expressed during sexual stage development and interrupt transmission, offer an alternative strategy to achieve malaria control. The post-fertilization antigen P25 mediates several functions essential to ookinete survival but is poorly immunogenic in humans. Previous clinical trials targeting this antigen have suggested that conjugation to a carrier protein could improve the immunogenicity of P25. Here we report the production, and characterization of a vaccine candidate composed of a chimeric P. vivax Merozoite Surface Protein 1 (cPvMSP1) genetically fused to P. vivax P25 (Pvs25) designed to enhance CD4+ T cell responses and its assessment in a murine model. We demonstrate that antibodies elicited by immunization with this chimeric protein recognize both the erythrocytic and sexual stages and are able to block the transmission of P. vivax field isolates in direct membrane-feeding assays. These findings provide support for the continued development of multi-stage transmission blocking vaccines targeting the life-cycle stage responsible for clinical disease and the sexual-stage development accountable for disease transmission simultaneously.
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Affiliation(s)
- Jessica N. McCaffery
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Jairo A. Fonseca
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, United States
| | - Balwan Singh
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Monica Cabrera-Mora
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Caitlin Bohannon
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Joshy Jacob
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
- Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, United States
| | - Myriam Arévalo-Herrera
- Caucaseco Scientific Research Center, Malaria Vaccine and Drug Development Center, Cali, Colombia
| | - Alberto Moreno
- Emory Vaccine Center, Yerkes National Primate Research Center, Emory University, Atlanta, GA, United States
- Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, GA, United States
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37
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Tan J, Piccoli L, Lanzavecchia A. The Antibody Response to Plasmodium falciparum: Cues for Vaccine Design and the Discovery of Receptor-Based Antibodies. Annu Rev Immunol 2018; 37:225-246. [PMID: 30566366 DOI: 10.1146/annurev-immunol-042617-053301] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Plasmodium falciparum remains a serious public health problem and a continuous challenge for the immune system due to the complexity and diversity of the pathogen. Recent advances from several laboratories in the characterization of the antibody response to the parasite have led to the identification of critical targets for protection and revealed a new mechanism of diversification based on the insertion of host receptors into immunoglobulin genes, leading to the production of receptor-based antibodies. These advances have opened new possibilities for vaccine design and passive antibody therapies to provide sterilizing immunity and control blood-stage parasites.
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Affiliation(s)
- Joshua Tan
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland; .,Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, United Kingdom.,Current affiliation: National Institute of Allergy and Infectious Diseases, Rockville, Maryland 20852, USA
| | - Luca Piccoli
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland;
| | - Antonio Lanzavecchia
- Institute for Research in Biomedicine, Università della Svizzera italiana, 6500 Bellinzona, Switzerland; .,VIR Biotechnology, San Francisco, California 94158, USA
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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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Antimalarial Transmission-Blocking Interventions: Past, Present, and Future. Trends Parasitol 2018; 34:735-746. [PMID: 30082147 DOI: 10.1016/j.pt.2018.07.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/14/2018] [Accepted: 07/02/2018] [Indexed: 12/17/2022]
Abstract
Malaria remains a major global health challenge. Appropriate use of current antimalarial tools has reduced the disease burden, but morbidity and mortality remain unacceptably high. It is widely accepted that, to achieve long-term control/eradication, it will be necessary to use interventions that inhibit the transmission of parasites to mosquitoes - these tools are termed transmission-blocking interventions (TBIs). This article aims to outline the rationale for the development of TBIs, with a focus on transmission-blocking drugs and (parasite-derived) transmission-blocking vaccines. We describe and summarise the current status of each of these intervention classes and attempt to identify future requirements in development, with a focus on the challenges of establishing each method within an integrated malarial control programme in the future.
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40
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Targeting the Conserved Fusion Loop of HAP2 Inhibits the Transmission of Plasmodium berghei and falciparum. Cell Rep 2018; 21:2868-2878. [PMID: 29212032 PMCID: PMC5732318 DOI: 10.1016/j.celrep.2017.11.024] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 10/05/2017] [Accepted: 11/02/2017] [Indexed: 01/01/2023] Open
Abstract
Inhibiting transmission of Plasmodium is a central strategy in malarial eradication, and the biological process of gamete fusion during fertilization is a proven target for this approach. The lack of a structure or known molecular function of current anti-malarial vaccine targets has previously been a hindrance in the development of transmission-blocking vaccines. Structure/function studies have indicated that the conserved gamete membrane fusion protein HAP2 is a class II viral fusion protein. Here, we demonstrate that targeting a function-critical site of the fusion/cd loop with species-specific antibodies reduces Plasmodium berghei transmission in vivo by 58.9% and in vitro fertilization by up to 89.9%. A corresponding reduction in P. falciparum transmission (75.5%/36.4% reductions in intensity/prevalence) is observed in complimentary field studies. These results emphasize conserved mechanisms of fusion in Apicomplexa, while highlighting an approach to design future anti-malarial transmission-blocking vaccines. Plasmodium HAP2 is a class II fusion protein Class II proteins are targetable to inhibit fertilization/transmission A short synthetically generated peptide can induce transmission-blocking immunity
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41
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Abstract
Malaria is the major cause of mortality and morbidity in tropical countries. The causative agent, Plasmodium sp., has a complex life cycle and is armed with various mechanisms which ensure its continuous transmission. Gametocytes represent the sexual stage of the parasite and are indispensable for the transmission of the parasite from the human host to the mosquito. Despite its vital role in the parasite's success, it is the least understood stage in the parasite's life cycle. The presence of gametocytes in asymptomatic populations and induction of gametocytogenesis by most antimalarial drugs warrants further investigation into its biology. With a renewed focus on malaria elimination and advent of modern technology available to biologists today, the field of gametocyte biology has developed swiftly, providing crucial insights into the molecular mechanisms driving sexual commitment. This review will summarise key current findings in the field of gametocyte biology and address the associated challenges faced in malaria detection, control and elimination.
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42
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Swihart BJ, Fay MP, Miura K. Statistical Methods for Standard Membrane-Feeding Assays to Measure Transmission Blocking or Reducing Activity in Malaria. J Am Stat Assoc 2018; 113:534-545. [PMID: 31007315 DOI: 10.1080/01621459.2017.1356313] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Transmission blocking vaccines for malaria are not designed to directly protect vaccinated people from malaria disease, but to reduce the probability of infecting other people by interfering with the growth of the malaria parasite in mosquitoes. Standard membrane-feeding assays compare the growth of parasites in mosquitoes from a test sample (using antibodies from a vaccinated person) compared to a control sample. There is debate about whether to estimate the transmission reducing activity (TRA) which compares the mean number of parasites between test and control samples, or transmission blocking activity (TBA) which compares the proportion of infected mosquitoes. TBA appears biologically more important since each mosquito with any parasites is potentially infective; however, TBA is less reproducible and may be an overly strict criterion for screening vaccine candidates. Through a statistical model, we show that the TBA estimand depends on μ c , the mean number of parasites in the control mosquitoes, a parameter not easily experimentally controlled. We develop a standardized TBA estimator based on the model and a given target value for μ c which has better mean squared error than alternative methods. We discuss types of statistical inference needed for using these assays for vaccine development.
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Affiliation(s)
| | - Michael P Fay
- Biostatistics Research Branch, NIAID, NIH, Rockville, MD
| | - Kazutoyo Miura
- National Institute of Allergy and Infectious Diseases, Laboratory of Malaria and Vector Research, National Institutes of Health, Rockville, MD
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43
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Famakinde DO. Mosquitoes and the Lymphatic Filarial Parasites: Research Trends and Budding Roadmaps to Future Disease Eradication. Trop Med Infect Dis 2018; 3:E4. [PMID: 30274403 PMCID: PMC6136629 DOI: 10.3390/tropicalmed3010004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 12/26/2017] [Accepted: 12/27/2017] [Indexed: 11/17/2022] Open
Abstract
The mosquito-borne lymphatic filariasis (LF) is a parasitic, neglected tropical disease that imposes an unbearable human scourge. Despite the unprecedented efforts in mass drug administration (MDA) and morbidity management, achieving the global LF elimination slated for the year 2020 has been thwarted by limited MDA coverage and ineffectiveness in the chemotherapeutic intervention. Moreover, successful and sustainable elimination of mosquito-vectored diseases is often encumbered by reintroduction and resurgence emanating from human residual or new infections being widely disseminated by the vectors even when chemotherapy proves effective, but especially in the absence of effective vaccines. This created impetus for strengthening the current defective mosquito control approach, and profound research in vector⁻pathogen systems and vector biology has been pushing the boundaries of ideas towards developing refined vector-harnessed control strategies. Eventual implementation of these emerging concepts will offer a synergistic approach that will not only accelerate LF elimination, but also augurs well for its future eradication. This brief review focuses on advances in mosquito⁻filaria research and considers the emerging prospects for future eradication of LF.
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Affiliation(s)
- Damilare O Famakinde
- Department of Medical Microbiology and Parasitology, College of Medicine of the University of Lagos, Idi-Araba, Lagos 100254, Nigeria.
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44
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Molina-Cruz A, Canepa GE, Barillas-Mury C. Plasmodium P47: a key gene for malaria transmission by mosquito vectors. Curr Opin Microbiol 2017; 40:168-174. [PMID: 29229188 PMCID: PMC5739336 DOI: 10.1016/j.mib.2017.11.029] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 11/27/2017] [Accepted: 11/28/2017] [Indexed: 11/16/2022]
Abstract
Malaria is caused by infection with Plasmodium parasites that have a complex life cycle. The parasite protein P47 is critical for disease transmission. P47 mediates mosquito immune evasion in both Plasmodium berghei (Pbs47) and Plasmodium falciparum (Pfs47), and has been shown to be important for optimal female gamete fertility in P. berghei. Pfs47 presents strong geographic structure in natural P. falciparum populations, consistent with natural selection of Pfs47 haplotypes by the mosquito immune system as the parasite adapted to new vector species worldwide. These key functions make Plasmodium P47 an attractive target to disrupt malaria transmission.
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Affiliation(s)
- Alvaro Molina-Cruz
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, United States.
| | - Gaspar E Canepa
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, United States
| | - Carolina Barillas-Mury
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, United States.
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45
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Molecular definition of multiple sites of antibody inhibition of malaria transmission-blocking vaccine antigen Pfs25. Nat Commun 2017; 8:1568. [PMID: 29146922 PMCID: PMC5691035 DOI: 10.1038/s41467-017-01924-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 10/25/2017] [Indexed: 01/07/2023] Open
Abstract
The Plasmodium falciparum Pfs25 protein (Pfs25) is a leading malaria transmission-blocking vaccine antigen. Pfs25 vaccination is intended to elicit antibodies that inhibit parasite development when ingested by Anopheles mosquitoes during blood meals. The Pfs25 three-dimensional structure has remained elusive, hampering a molecular understanding of its function and limiting immunogen design. We report six crystal structures of Pfs25 in complex with antibodies elicited by immunization via Pfs25 virus-like particles in human immunoglobulin loci transgenic mice. Our structural findings reveal the fine specificities associated with two distinct immunogenic sites on Pfs25. Importantly, one of these sites broadly overlaps with the epitope of the well-known 4B7 mouse antibody, which can be targeted simultaneously by antibodies that target a non-overlapping site to additively increase parasite inhibition. Our molecular characterization of inhibitory antibodies informs on the natural disposition of Pfs25 on the surface of ookinetes and provides the structural blueprints to design next-generation immunogens. Plasmodium falciparum protein Pfs25 is a promising malaria transmission blocking vaccine antigen. Here, Scally et al. determine the crystal structure of Pfs25 and identify antigenic sites that are recognized by transmission-blocking antibodies elicited in human immunoglobulin loci transgenic mice.
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46
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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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47
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Healer J, Cowman AF, Kaslow DC, Birkett AJ. Vaccines to Accelerate Malaria Elimination and Eventual Eradication. Cold Spring Harb Perspect Med 2017; 7:cshperspect.a025627. [PMID: 28490535 DOI: 10.1101/cshperspect.a025627] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Remarkable progress has been made in coordinated malaria control efforts with substantial reductions in malaria-associated deaths and morbidity achieved through mass administration of drugs and vector control measures including distribution of long-lasting insecticide-impregnated bednets and indoor residual spraying. However, emerging resistance poses a significant threat to the sustainability of these interventions. In this light, the malaria research community has been charged with the development of a highly efficacious vaccine to complement existing malaria elimination measures. As the past 40 years of investment in this goal attests, this is no small feat. The malaria parasite is a highly complex organism, exquisitely adapted for survival under hostile conditions within human and mosquito hosts. Here we review current vaccine strategies to accelerate elimination and the potential for novel and innovative approaches to vaccine design through a better understanding of the host-parasite interaction.
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Affiliation(s)
- Julie Healer
- Walter & Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
| | - Alan F Cowman
- Walter & Eliza Hall Institute of Medical Research, Melbourne, Victoria 3052, Australia
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48
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Sandeu MM, Bayibéki AN, Tchioffo MT, Abate L, Gimonneau G, Awono-Ambéné PH, Nsango SE, Diallo D, Berry A, Texier G, Morlais I. Do the venous blood samples replicate malaria parasite densities found in capillary blood? A field study performed in naturally-infected asymptomatic children in Cameroon. Malar J 2017; 16:345. [PMID: 28818084 PMCID: PMC5561596 DOI: 10.1186/s12936-017-1978-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 08/07/2017] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The measure of new drug- or vaccine-based approaches for malaria control is based on direct membrane feeding assays (DMFAs) where gametocyte-infected blood samples are offered to mosquitoes through an artificial feeder system. Gametocyte donors are identified by the microscopic detection and quantification of malaria blood stages on blood films prepared using either capillary or venous blood. However, parasites are known to sequester in the microvasculature and this phenomenon may alter accurate detection of parasites in blood films. The blood source may then impact the success of mosquito feeding experiments and investigations are needed for the implementation of DMFAs under natural conditions. METHODS Thick blood smears were prepared from blood obtained from asymptomatic children attending primary schools in the vicinity of Mfou (Cameroon) over four transmission seasons. Parasite densities were determined microscopically from capillary and venous blood for 137 naturally-infected gametocyte carriers. The effect of the blood source on gametocyte and asexual stage densities was then assessed by fitting cumulative link mixed models (CLMM). DMFAs were performed to compare the infectiousness of gametocytes from the different blood sources to mosquitoes. RESULTS Prevalence of Plasmodium falciparum asexual stages among asymptomatic children aged from 4 to 15 years was 51.8% (2116/4087). The overall prevalence of P. falciparum gametocyte carriage was 8.9% and varied from one school to another. No difference in the density of gametocyte and asexual stages was found between capillary and venous blood. Attempts to perform DMFAs with capillary blood failed. CONCLUSIONS Plasmodium falciparum malaria parasite densities do not differ between capillary and venous blood in asymptomatic subjects for both gametocyte and trophozoite stages. This finding suggests that the blood source should not interfere with transmission efficiency in DMFAs.
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Affiliation(s)
- Maurice M. Sandeu
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP288, Yaoundé, Cameroon
| | - Albert N. Bayibéki
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP288, Yaoundé, Cameroon
| | - Majoline T. Tchioffo
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP288, Yaoundé, Cameroon
- UMR MIVEGEC, Institut de Recherche pour le Développement, 911 Avenue Agropolis, BP64501, 34394 Montpellier Cedex, France
| | - Luc Abate
- UMR MIVEGEC, Institut de Recherche pour le Développement, 911 Avenue Agropolis, BP64501, 34394 Montpellier Cedex, France
| | - Geoffrey Gimonneau
- UMR MIVEGEC, Institut de Recherche pour le Développement, 911 Avenue Agropolis, BP64501, 34394 Montpellier Cedex, France
| | - Parfait H. Awono-Ambéné
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP288, Yaoundé, Cameroon
| | - Sandrine E. Nsango
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP288, Yaoundé, Cameroon
- Université de Douala, Faculté de Médecine et des Sciences Pharmaceutiques, BP2701 Douala, Cameroon
| | - Diadier Diallo
- PATH Malaria Vaccine Initiative, Washington, DC 20001 USA
| | - Antoine Berry
- Centre de Physiopathologie de Toulouse Purpan, INSERM U1043, CNRS, UMR5282, Université de Toulouse III, BP 3028, 31024 Toulouse Cedex 03, France
- Centre Hospitalier Universitaire de Toulouse, TSA 40031, 31059 Toulouse, France
| | - Gaétan Texier
- Centre d’épidémiologie et de santé publique des armées, 111 avenue de la Corse, BP40026, 13568 Marseille Cedex 02, France
- UMR 912-SESSTIM-INSERM/IRD, Université Aix-Marseille, 27 bd Jean Moulin, 13385 Marseille Cedex 05, France
| | - Isabelle Morlais
- Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, BP288, Yaoundé, Cameroon
- UMR MIVEGEC, Institut de Recherche pour le Développement, 911 Avenue Agropolis, BP64501, 34394 Montpellier Cedex, France
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49
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Bompard A, Da DF, Yerbanga RS, Biswas S, Kapulu M, Bousema T, Lefèvre T, Cohuet A, Churcher TS. Evaluation of two lead malaria transmission blocking vaccine candidate antibodies in natural parasite-vector combinations. Sci Rep 2017; 7:6766. [PMID: 28754921 PMCID: PMC5533793 DOI: 10.1038/s41598-017-06130-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 06/08/2017] [Indexed: 12/25/2022] Open
Abstract
Transmission blocking vaccines (TBV) which aim to control malaria by inhibiting human-to-mosquito transmission show considerable promise though their utility against naturally circulating parasites remains unknown. The efficacy of two lead candidates targeting Pfs25 and Pfs230 antigens to prevent onwards transmission of naturally occurring parasites to a local mosquito strain is assessed using direct membrane feeding assays and murine antibodies in Burkina Faso. The transmission blocking activity of both candidates depends on the level of parasite exposure (as assessed by the mean number of oocysts in control mosquitoes) and antibody titers. A mathematical framework is devised to allow the efficacy of different candidates to be directly compared and determine the minimal antibody titers required to halt transmission in different settings. The increased efficacy with diminishing parasite exposure indicates that the efficacy of vaccines targeting either Pfs25 or Pfs230 may increase as malaria transmission declines. This has important implications for late-stage candidate selection and assessing how they can support the drive for malaria elimination.
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Affiliation(s)
- Anais Bompard
- MRC Centre for Outbreak Analysis and Modelling, Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, United Kingdom.
| | - Dari F Da
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.,Unité MIVEGEC, IRD 224-CNRS 5290-Université Montpellier, Montpellier, France
| | | | - Sumi Biswas
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Melissa Kapulu
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Teun Bousema
- Department of Medical Microbiology, Nijmegen, The Netherlands
| | - Thierry Lefèvre
- Institut de Recherche en Sciences de la Santé, Bobo-Dioulasso, Burkina Faso.,Unité MIVEGEC, IRD 224-CNRS 5290-Université Montpellier, Montpellier, France.,Laboratoire mixte international sur les vecteurs (LAMIVECT), Bobo Dioulasso, Burkina Faso
| | - Anna Cohuet
- Unité MIVEGEC, IRD 224-CNRS 5290-Université Montpellier, Montpellier, France
| | - Thomas S Churcher
- MRC Centre for Outbreak Analysis and Modelling, Infectious Disease Epidemiology, Imperial College London, Norfolk Place, London, W2 1PG, United Kingdom
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50
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Plasmodium berghei PIMMS2 Promotes Ookinete Invasion of the Anopheles gambiae Mosquito Midgut. Infect Immun 2017; 85:IAI.00139-17. [PMID: 28559405 PMCID: PMC5520436 DOI: 10.1128/iai.00139-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/11/2017] [Indexed: 12/21/2022] Open
Abstract
Mosquito midgut stages of the malaria parasite present an attractive biological system to study host-parasite interactions and develop interventions to block disease transmission. Mosquito infection ensues upon oocyst development that follows ookinete invasion and traversal of the mosquito midgut epithelium. Here, we report the characterization of PIMMS2 (Plasmodium invasion of mosquito midgut screen candidate 2), a Plasmodium berghei protein with structural similarities to subtilisin-like proteins. PIMMS2 orthologs are present in the genomes of all plasmodia and are mapped between the subtilisin-encoding genes SUB1 and SUB3. P. berghei PIMMS2 is specifically expressed in zygotes and ookinetes and is localized on the ookinete surface. Loss of PIMMS2 function through gene disruption by homologous recombination leads to normal development of motile ookinetes that exhibit a severely impaired capacity to traverse the mosquito midgut and transform to oocysts. Genetic complementation of the disrupted locus with a mutated PIMMS2 allele reveals that amino acid residues corresponding to the putative subtilisin-like catalytic triad are important but not essential for protein function. Our data demonstrate that PIMMS2 is a novel ookinete-specific protein that promotes parasite traversal of the mosquito midgut epithelium and establishment of mosquito infection.
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