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Ventocilla JA, Tapia LL, Ponce R, Franco A, Leelawong M, Aguiar JC, Baldeviano GC, Wilder BK. Evaluation of naturally acquired immune responses against novel pre-erythrocytic Plasmodium vivax proteins in a low endemic malaria population located in the Peruvian Amazon Basin. Malar J 2024; 23:163. [PMID: 38783317 PMCID: PMC11118720 DOI: 10.1186/s12936-024-04978-z] [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: 12/13/2023] [Accepted: 05/09/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Plasmodium vivax represents the most geographically widespread human malaria parasite affecting civilian and military populations in endemic areas. Targeting the pre-erythrocytic (PE) stage of the parasite life cycle is especially appealing for developing P. vivax vaccines as it would prevent disease and transmission. Here, naturally acquired immunity to a panel of P. vivax PE antigens was explored, which may facilitate vaccine development and lead to a better understanding of naturally acquired PE immunity. METHODS Twelve P. vivax PE antigens orthologous to a panel of P. falciparum antigens previously identified as highly immunogenic in protected subjects after immunization with radiation attenuated sporozoites (RAS) were used for evaluation of humoral and cellular immunity by ELISA and IFN-γ ELISpot. Samples from P. vivax infected individuals (n = 76) from a low endemic malaria region in the Peruvian Amazon Basin were used. RESULTS In those clinical samples, all PE antigens evaluated showed positive IgG antibody reactivity with a variable prevalence of 58-99% in recently P. vivax diagnosed patients. The magnitude of the IgG antibody response against PE antigens was lower compared with blood stage antigens MSP1 and DBP-II, although antibody levels persisted better for PE antigens (average decrease of 6% for PE antigens and 43% for MSP1, p < 0.05). Higher IgG antibodies was associated with one or more previous malaria episodes only for blood stage antigens (p < 0.001). High IgG responders across PE and blood stage antigens showed significantly lower parasitaemia compared to low IgG responders (median 1,921 vs 4,663 par/µl, p < 0.05). In a subgroup of volunteers (n = 17),positive IFN-γ T cell response by ELISPOT was observed in 35% vs 9-35% against blood stage MSP1 and PE antigens, respectively, but no correlation with IgG responses. CONCLUSIONS These results demonstrate clear humoral and T cell responses against P. vivax PE antigens in individuals naturally infected with P. vivax. These data identify novel attractive PE antigens suitable for use in the potential development and selection of new malaria vaccine candidates which can be used as a part of malaria prevention strategies in civilian and military populations living in P. vivax endemic areas.
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Affiliation(s)
- Julio A Ventocilla
- Vysnova Partners Inc., Bethesda, USA
- Universidad Peruana Cayetano Heredia, Lima, Peru
| | - L Lorena Tapia
- U.S. Naval Medical Research Unit South, Lima-Peru (NAMRU SOUTH), Bellavista, Peru
| | | | | | - Mindy Leelawong
- U.S. Naval Medical Research Unit South, Lima-Peru (NAMRU SOUTH), Bellavista, Peru
- NYC Department of Health and Mental Hygiene, Long Island City, USA
| | | | - G Christian Baldeviano
- U.S. Naval Medical Research Unit South, Lima-Peru (NAMRU SOUTH), Bellavista, Peru
- Bluebird Bio, Inc, Somerville, USA
| | - Brandon K Wilder
- U.S. Naval Medical Research Unit South, Lima-Peru (NAMRU SOUTH), Bellavista, Peru.
- Oregon Health & Science University, Portland, USA.
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2
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Martinez FJ, White M, Guillotte-Blisnick M, Huon C, Boucharlat A, Agou F, England P, Popovici J, Hou MM, Silk SE, Barrett JR, Nielsen CM, Reimer JM, Mukherjee P, Chauhan VS, Minassian AM, Draper SJ, Chitnis CE. PvDBPII elicits multiple antibody-mediated mechanisms that reduce growth in a Plasmodium vivax challenge trial. NPJ Vaccines 2024; 9:10. [PMID: 38184681 PMCID: PMC10771494 DOI: 10.1038/s41541-023-00796-7] [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: 08/17/2023] [Accepted: 12/07/2023] [Indexed: 01/08/2024] Open
Abstract
The receptor-binding domain, region II, of the Plasmodium vivax Duffy binding protein (PvDBPII) binds the Duffy antigen on the reticulocyte surface to mediate invasion. A heterologous vaccine challenge trial recently showed that a delayed dosing regimen with recombinant PvDBPII SalI variant formulated with adjuvant Matrix-MTM reduced the in vivo parasite multiplication rate (PMR) in immunized volunteers challenged with the Thai P. vivax isolate PvW1. Here, we describe extensive analysis of the polyfunctional antibody responses elicited by PvDBPII immunization and identify immune correlates for PMR reduction. A classification algorithm identified antibody features that significantly contribute to PMR reduction. These included antibody titre, receptor-binding inhibitory titre, dissociation constant of the PvDBPII-antibody interaction, complement C1q and Fc gamma receptor binding and specific IgG subclasses. These data suggest that multiple immune mechanisms elicited by PvDBPII immunization are likely to be associated with protection and the immune correlates identified could guide the development of an effective vaccine for P. vivax malaria. Importantly, all the polyfunctional antibody features that correlated with protection cross-reacted with both PvDBPII SalI and PvW1 variants, suggesting that immunization with PvDBPII should protect against diverse P. vivax isolates.
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Affiliation(s)
- Francisco J Martinez
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, Paris, France
| | - Michael White
- Infectious Disease Epidemiology and Analytics G5 Unit, Institut Pasteur, Université Paris Cité, Paris, France
| | | | - Christèle Huon
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, Paris, France
| | - Alix Boucharlat
- Chemogenomic and Biological Screening Core Facility, C2RT, Institut Pasteur, Université Paris Cité, CNRS UMR 3523, Paris, France
| | - Fabrice Agou
- Chemogenomic and Biological Screening Core Facility, C2RT, Institut Pasteur, Université Paris Cité, CNRS UMR 3523, Paris, France
| | - Patrick England
- Molecular Biophysics Facility, CNRS UMR 3528, Institut Pasteur, Paris, France
| | - Jean Popovici
- Malaria Reasearch Unit, Institut Pasteur du Cambodge, Pnom Penh, Cambodia
| | - Mimi M Hou
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, OX1 3QU, UK
| | - Sarah E Silk
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, OX1 3QU, UK
| | - Jordan R Barrett
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, OX1 3QU, UK
| | - Carolyn M Nielsen
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, OX1 3QU, UK
| | | | | | - Virander S Chauhan
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Angela M Minassian
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, OX1 3QU, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Simon J Draper
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, OX1 3QU, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Chetan E Chitnis
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, Paris, France.
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3
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Watson QD, Carias LL, Malachin A, Redinger KR, Bosch J, Bardelli M, Baldor L, Feufack-Donfack LB, Popovici J, Moon RW, Draper SJ, Zimmerman PA, King CL. Human monoclonal antibodies inhibit invasion of transgenic Plasmodium knowlesi expressing Plasmodium vivax Duffy binding protein. Malar J 2023; 22:369. [PMID: 38049801 PMCID: PMC10696754 DOI: 10.1186/s12936-023-04766-1] [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: 07/10/2023] [Accepted: 10/24/2023] [Indexed: 12/06/2023] Open
Abstract
BACKGROUND Plasmodium vivax has been more resistant to various control measures than Plasmodium falciparum malaria because of its greater transmissibility and ability to produce latent parasite forms. Therefore, developing P. vivax vaccines and therapeutic monoclonal antibodies (humAbs) remains a high priority. The Duffy antigen receptor for chemokines (DARC) expressed on erythrocytes is central to P. vivax invasion of reticulocytes. P. vivax expresses a Duffy binding protein (PvDBP) on merozoites, a DARC ligand, and the DARC: PvDBP interaction is critical for P. vivax blood stage malaria. Therefore, PvDBP is a leading vaccine candidate for P. vivax and a target for therapeutic human monoclonal antibodies (humAbs). METHODS Here, the functional activity of humAbs derived from naturally exposed and vaccinated individuals are compared for the first time using easily cultured Plasmodium knowlesi (P. knowlesi) that had been genetically modified to replace its endogenous PkDBP orthologue with PvDBP to create a transgenic parasite, PkPvDBPOR. This transgenic parasite requires DARC to invade human erythrocytes but is not reticulocyte restricted. This model was used to evaluate the invasion inhibition potential of 12 humAbs (9 naturally acquired; 3 vaccine-induced) targeting PvDBP individually and in combinations using growth inhibition assays (GIAs). RESULTS The PvDBP-specific humAbs demonstrated 70-100% inhibition of PkPvDBPOR invasion with the IC50 values ranging from 51 to 338 µg/mL for the 9 naturally acquired (NA) humAbs and 33 to 99 µg/ml for the 3 vaccine-induced (VI) humAbs. To evaluate antagonistic, additive, or synergistic effects, six pairwise combinations were performed using select humAbs. Of these combinations tested, one NA/NA (099100/094083) combination demonstrated relatively strong additive inhibition between 10 and 100 µg/mL; all combinations of NA and VI humAbs showed additive inhibition at concentrations below 25 µg/mL and antagonism at higher concentrations. None of the humAb combinations showed synergy. Invasion inhibition efficacy by some mAbs shown with PkPvDBPOR was closely replicated using P. vivax clinical isolates. CONCLUSION The PkPvDBPOR transgenic model is a robust surrogate of P. vivax to assess invasion and growth inhibition of human monoclonal Abs recognizing PvDBP individually and in combination. There was no synergistic interaction for growth inhibition with the humAbs tested here that target different epitopes or subdomains of PvDBP, suggesting little benefit in clinical trials using combinations of these humAbs.
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Affiliation(s)
- Quentin D Watson
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Lenore L Carias
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Alyssa Malachin
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Karli R Redinger
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Jürgen Bosch
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | | | - Lea Baldor
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | | | - Jean Popovici
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Robert W Moon
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Simon J Draper
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Peter A Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
| | - Christopher L King
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA.
- Veterans Affairs Medical Center, Cleveland, OH, USA.
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4
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Dickey TH, Tolia NH. Designing an effective malaria vaccine targeting Plasmodium vivax Duffy-binding protein. Trends Parasitol 2023; 39:850-858. [PMID: 37481347 PMCID: PMC11099547 DOI: 10.1016/j.pt.2023.06.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 06/26/2023] [Accepted: 06/26/2023] [Indexed: 07/24/2023]
Abstract
Malaria caused by the Plasmodium vivax parasite is a major global health burden. Immunity against blood-stage infection reduces parasitemia and disease severity. Duffy-binding protein (DBP) is the primary parasite protein responsible for the invasion of red blood cells and it is a leading subunit vaccine candidate. An effective vaccine, however, is still lacking despite decades of interest in DBP as a vaccine candidate. This review discusses the reasons for targeting DBP, the challenges associated with developing a vaccine, and modern structural vaccinology methods that could be used to create an effective DBP vaccine. Next-generation DBP vaccines have the potential to elicit a broadly protective immune response and provide durable and potent protection from P. vivax malaria.
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Affiliation(s)
- Thayne H Dickey
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20894, USA
| | - Niraj H Tolia
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20894, USA.
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5
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Tapaopong P, da Silva G, Chainarin S, Suansomjit C, Manopwisedjaroen K, Cui L, Koepfli C, Sattabongkot J, Nguitragool W. Genetic diversity and molecular evolution of Plasmodium vivax Duffy Binding Protein and Merozoite Surface Protein-1 in northwestern Thailand. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2023; 113:105467. [PMID: 37330027 PMCID: PMC10548344 DOI: 10.1016/j.meegid.2023.105467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/22/2023] [Accepted: 06/14/2023] [Indexed: 06/19/2023]
Abstract
The local diversity and population structure of malaria parasites vary across different regions of the world, reflecting variations in transmission intensity, host immunity, and vector species. This study aimed to use amplicon sequencing to investigate the genotypic patterns and population structure of P. vivax isolates from a highly endemic province of Thailand in recent years. Amplicon deep sequencing was performed on 70 samples for the 42-kDa region of pvmsp1 and domain II of pvdbp. Unique haplotypes were identified and a network constructed to illustrate genetic relatedness in northwestern Thailand. Based on this dataset of 70 samples collected between 2015 and 2021, 16 and 40 unique haplotypes were identified in pvdbpII and pvmsp142kDa, respectively. Nucleotide diversity was higher in pvmsp142kDa than in pvdbpII (π = 0.027 and 0.012), as was haplotype diversity (Hd = 0.962 and 0.849). pvmsp142kDa also showed a higher recombination rate and higher levels of genetic differentiation (Fst) in northwestern Thailand versus other regions (0.2761-0.4881). These data together suggested that the genetic diversity of P. vivax in northwestern Thailand at these two studied loci evolved under a balancing selection, most likely host immunity. The lower genetic diversity of pvdbpII may reflect its stronger functional constrain. In addition, despite the balancing selection, a decrease in genetic diversity was observed. Hd of pvdbpII decreased from 0.874 in 2015-2016 to 0.778 in 2018-2021; π of pvmsp142kDa decreased from 0.030 to 0.022 over the same period. Thus, the control activities must have had a strong impact on the parasite population size. The findings from this study provide an understanding of P. vivax population structure and the evolutionary force on vaccine candidates. They also established a new baseline for tracking future changes in P. vivax diversity in the most malarious area of Thailand.
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Affiliation(s)
- Parsakorn Tapaopong
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Gustavo da Silva
- Department of Biological Sciences, Eck Institute for Global Health, Galvin Life Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Sittinont Chainarin
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Chayanut Suansomjit
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | | | - Liwang Cui
- Division of Infectious Diseases and International Medicine, Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Cristian Koepfli
- Department of Biological Sciences, Eck Institute for Global Health, Galvin Life Sciences, University of Notre Dame, Notre Dame, IN, USA
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Wang Nguitragool
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand; Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.
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6
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Martinez FJ, Guillotte-Blisnick M, Huon C, England P, Popovici J, Laude H, Arowas L, Ungeheuer MN, Reimer JM, Carter D, Reed S, Mukherjee P, Chauhan VS, Chitnis CE. Immunogenicity of a Plasmodium vivax vaccine based on the duffy binding protein formulated using adjuvants compatible for use in humans. Sci Rep 2023; 13:13904. [PMID: 37626150 PMCID: PMC10457348 DOI: 10.1038/s41598-023-40043-6] [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: 05/02/2023] [Accepted: 08/03/2023] [Indexed: 08/27/2023] Open
Abstract
The invasion of reticulocytes by Plasmodium vivax merozoites is dependent on the interaction of the Plasmodium vivax Duffy Binding Protein (PvDBP) with the Duffy antigen receptor for chemokines (DARC). The N-terminal cysteine-rich region II of PvDBP (PvDBPII), which binds DARC, is a leading P. vivax malaria vaccine candidate. Here, we have evaluated the immunogenicity of recombinant PvDBPII formulated with the adjuvants Matrix-M and GLA-SE in mice. Analysis of the antibody responses revealed comparable ELISA recognition titres as well as similar recognition of native PvDBP in P. vivax schizonts by immunofluorescence assay. Moreover, antibodies elicited by the two adjuvant formulations had similar functional properties such as avidity, isotype profile and inhibition of PvDBPII-DARC binding. Furthermore, the anti-PvDBPII antibodies were able to block the interaction of DARC with the homologous PvDBPII SalI allele as well as the heterologous PvDBPII PvW1 allele from a Thai clinical isolate that is used for controlled human malaria infections (CHMI). The cross-reactivity of these antibodies with PvW1 suggest that immunization with the PvDBPII SalI strain should neutralize reticulocyte invasion by the challenge P. vivax strain PvW1.
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Affiliation(s)
- Francisco J Martinez
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr. Roux, 75015, Paris, France
| | - Micheline Guillotte-Blisnick
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr. Roux, 75015, Paris, France
| | - Christèle Huon
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr. Roux, 75015, Paris, France
| | - Patrick England
- Plate-Forme de Biophysique Moléculaire, CNRS UMR 3528, Institut Pasteur, Université Paris Cité, Paris, France
| | - Jean Popovici
- Malaria Research Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Hélène Laude
- Investigational Clinical Service and Access to Research Bio-Resources (ICAReB), Institut Pasteur, Paris, France
| | - Laurence Arowas
- Investigational Clinical Service and Access to Research Bio-Resources (ICAReB), Institut Pasteur, Paris, France
| | - Marie-Noëlle Ungeheuer
- Investigational Clinical Service and Access to Research Bio-Resources (ICAReB), Institut Pasteur, Paris, France
| | | | - Darrick Carter
- HDT Bio, Seattle, WA, USA
- PAI Life Sciences Inc., Seattle, WA, USA
| | | | | | - Virander S Chauhan
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Chetan E Chitnis
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr. Roux, 75015, Paris, France.
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7
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Hou MM, Barrett JR, Themistocleous Y, Rawlinson TA, Diouf A, Martinez FJ, Nielsen CM, Lias AM, King LDW, Edwards NJ, Greenwood NM, Kingham L, Poulton ID, Khozoee B, Goh C, Hodgson SH, Mac Lochlainn DJ, Salkeld J, Guillotte-Blisnick M, Huon C, Mohring F, Reimer JM, Chauhan VS, Mukherjee P, Biswas S, Taylor IJ, Lawrie AM, Cho JS, Nugent FL, Long CA, Moon RW, Miura K, Silk SE, Chitnis CE, Minassian AM, Draper SJ. Vaccination with Plasmodium vivax Duffy-binding protein inhibits parasite growth during controlled human malaria infection. Sci Transl Med 2023; 15:eadf1782. [PMID: 37437014 PMCID: PMC7615121 DOI: 10.1126/scitranslmed.adf1782] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 06/05/2023] [Indexed: 07/14/2023]
Abstract
There are no licensed vaccines against Plasmodium vivax. We conducted two phase 1/2a clinical trials to assess two vaccines targeting P. vivax Duffy-binding protein region II (PvDBPII). Recombinant viral vaccines using chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) vectors as well as a protein and adjuvant formulation (PvDBPII/Matrix-M) were tested in both a standard and a delayed dosing regimen. Volunteers underwent controlled human malaria infection (CHMI) after their last vaccination, alongside unvaccinated controls. Efficacy was assessed by comparisons of parasite multiplication rates in the blood. PvDBPII/Matrix-M, given in a delayed dosing regimen, elicited the highest antibody responses and reduced the mean parasite multiplication rate after CHMI by 51% (n = 6) compared with unvaccinated controls (n = 13), whereas no other vaccine or regimen affected parasite growth. Both viral-vectored and protein vaccines were well tolerated and elicited expected, short-lived adverse events. Together, these results support further clinical evaluation of the PvDBPII/Matrix-M P. vivax vaccine.
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Affiliation(s)
- Mimi M Hou
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Jordan R Barrett
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | | | | | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Francisco J Martinez
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Carolyn M Nielsen
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Amelia M Lias
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Lloyd D W King
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Nick J Edwards
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Lucy Kingham
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Ian D Poulton
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Cyndi Goh
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Susanne H Hodgson
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Dylan J Mac Lochlainn
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Jo Salkeld
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Micheline Guillotte-Blisnick
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Christèle Huon
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Franziska Mohring
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | | | - Virander S Chauhan
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | | | - Sumi Biswas
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Iona J Taylor
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Jee-Sun Cho
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Fay L Nugent
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
| | - Carole A Long
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Robert W Moon
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London WC1E 7HT, UK
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Sarah E Silk
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Chetan E Chitnis
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Angela M Minassian
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Simon J Draper
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK
- Jenner Institute, University of Oxford, Oxford OX3 7DQ, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
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8
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Moskovitz R, Pholcharee T, DonVito SM, Guloglu B, Lowe E, Mohring F, Moon RW, Higgins MK. Structural basis for DARC binding in reticulocyte invasion by Plasmodium vivax. Nat Commun 2023; 14:3637. [PMID: 37336887 DOI: 10.1038/s41467-023-39357-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/06/2023] [Indexed: 06/21/2023] Open
Abstract
The symptoms of malaria occur during the blood stage of infection, when the parasite replicates within human red blood cells. The human malaria parasite, Plasmodium vivax, selectively invades reticulocytes in a process which requires an interaction between the ectodomain of the human DARC receptor and the Plasmodium vivax Duffy-binding protein, PvDBP. Previous studies have revealed that a small helical peptide from DARC binds to region II of PvDBP (PvDBP-RII). However, it is also known that sulphation of tyrosine residues on DARC affects its binding to PvDBP and these residues were not observed in previous structures. We therefore present the structure of PvDBP-RII bound to sulphated DARC peptide, showing that a sulphate on tyrosine 41 binds to a charged pocket on PvDBP-RII. We use molecular dynamics simulations, affinity measurements and growth-inhibition experiments in parasites to confirm the importance of this interaction. We also reveal the epitope for vaccine-elicited growth-inhibitory antibody DB1. This provides a complete understanding of the binding of PvDBP-RII to DARC and will guide the design of vaccines and therapeutics to target this essential interaction.
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Affiliation(s)
- Re'em Moskovitz
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Tossapol Pholcharee
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Sophia M DonVito
- London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Bora Guloglu
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Edward Lowe
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
| | - Franziska Mohring
- London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Robert W Moon
- London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK
| | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
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9
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Watson QD, Carias LL, Malachin A, Redinger KR, Bosch J, Bardelli M, Moon RW, Draper SJ, Zimmerman PA, King CL. Naturally-acquired and Vaccine-induced Human Monoclonal Antibodies to Plasmodium vivax Duffy Binding Protein Inhibit Invasion of Plasmodium knowlesi (PvDBPOR) Transgenic Parasites. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.07.531647. [PMID: 36945444 PMCID: PMC10028882 DOI: 10.1101/2023.03.07.531647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
The Duffy antigen receptor for chemokines (DARC) expressed on erythrocytes is central to Plasmodium vivax (Pv) invasion of reticulocytes. Pv expresses a Duffy binding protein (PvDBP) on merozoites, a DARC ligand, and their protein-protein interaction is central to vivax blood stage malaria. Here we compared the functional activity of humAbs derived from naturally exposed and vaccinated individuals for the first time using easily cultured P. knowlesi (Pk) that had been genetically modified to replace its endogenous PkDBP orthologue with PvDBP to create a transgenic parasite, PkPvDBPOR. This transgenic parasite requires DARC to invade human erythrocytes but is not reticulocyte restricted. Using this model, we evaluated the invasion inhibition potential of 12 humAbs (9 naturally acquired; 3 vaccine-induced) targeting PvDBP individually and in combinations using growth inhibition assays (GIAs). The PvDBP-specific humAbs demonstrated 70-100% inhibition of PkPvDBPOR invasion with the IC50 values ranging from 51 to 338 μg/mL for the 9 naturally acquired (NA) humAbs and 33 to 99 μg/ml for the 3 vaccine-induced (VI) humAbs. To evaluate antagonistic, additive, or synergistic effects, six pairwise combinations were performed using select humAbs. Of these combinations tested, one NA/NA (099100/094083) combination demonstrated relatively strong additive inhibition between 10-100 μg/mL; all combinations of NA and VI humAbs showed additive inhibition at concentrations below 25 μg/mL and antagonism at higher concentrations. None of the humAb combinations showed synergy. This PkPvDBPOR model system enables efficient assessment of NA and VI humAbs individually and in combination.
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Affiliation(s)
- Quentin D. Watson
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Lenore L. Carias
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Alyssa Malachin
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Karli R. Redinger
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Jürgen Bosch
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | | | - Robert W. Moon
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Simon J. Draper
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Peter A. Zimmerman
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Christopher L. King
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Veterans Affairs Medical Center, Cleveland, OH
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10
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Torres K, Ferreira MU, Castro MC, Escalante AA, Conn JE, Villasis E, da Silva Araujo M, Almeida G, Rodrigues PT, Corder RM, Fernandes ARJ, Calil PR, Ladeia WA, Garcia-Castillo SS, Gomez J, do Valle Antonelli LR, Gazzinelli RT, Golenbock DT, Llanos-Cuentas A, Gamboa D, Vinetz JM. Malaria Resilience in South America: Epidemiology, Vector Biology, and Immunology Insights from the Amazonian International Center of Excellence in Malaria Research Network in Peru and Brazil. Am J Trop Med Hyg 2022; 107:168-181. [PMID: 36228921 PMCID: PMC9662219 DOI: 10.4269/ajtmh.22-0127] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/28/2022] [Indexed: 11/07/2022] Open
Abstract
The 1990s saw the rapid reemergence of malaria in Amazonia, where it remains an important public health priority in South America. The Amazonian International Center of Excellence in Malaria Research (ICEMR) was designed to take a multidisciplinary approach toward identifying novel malaria control and elimination strategies. Based on geographically and epidemiologically distinct sites in the Northeastern Peruvian and Western Brazilian Amazon regions, synergistic projects integrate malaria epidemiology, vector biology, and immunology. The Amazonian ICEMR's overarching goal is to understand how human behavior and other sociodemographic features of human reservoirs of transmission-predominantly asymptomatically parasitemic people-interact with the major Amazonian malaria vector, Nyssorhynchus (formerly Anopheles) darlingi, and with human immune responses to maintain malaria resilience and continued endemicity in a hypoendemic setting. Here, we will review Amazonian ICEMR's achievements on the synergies among malaria epidemiology, Plasmodium-vector interactions, and immune response, and how those provide a roadmap for further research, and, most importantly, point toward how to achieve malaria control and elimination in the Americas.
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Affiliation(s)
- Katherine Torres
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Marcia C. Castro
- Department of Global Health and Population, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Ananias A. Escalante
- Department of Biology and Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, Pennsylvania
| | - Jan E. Conn
- Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Albany, New York
- Wadsworth Center, New York State Department of Health, Albany, New York
| | - Elizabeth Villasis
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Gregorio Almeida
- Instituto de Pesquisas Rene Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Brazil
| | - Priscila T. Rodrigues
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Rodrigo M. Corder
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Anderson R. J. Fernandes
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Priscila R. Calil
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Winni A. Ladeia
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Sao Paulo, Brazil
| | - Stefano S. Garcia-Castillo
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joaquin Gomez
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - 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, Massachusetts
| | - Douglas T. Golenbock
- Division of Infectious Disease and Immunology, Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Alejandro Llanos-Cuentas
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Dionicia Gamboa
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Joseph M. Vinetz
- Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
- Laboratorios de Investigación y Desarrollo, Facultad de Ciencias y Filosofía, Universidad Peruana Cayetano Heredia, Lima, Peru
- Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, New Haven, Connecticut
- Address correspondence to Joseph M. Vinetz, Section of Infectious Diseases, Department of Internal Medicine, Yale School of Medicine, 25 York St., Winchester 403D, PO Box 802022, New Haven, CT 06520. E-mail:
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11
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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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12
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Lima BAS, Fernandes GM, Torres LM, Pires CV, Alves JRS, Moreira-Nascimento SL, Nascimento MFA, Afonso SL, Costa HL, Cerávolo IP, Sousa TN, Soares IS, Ntumngia FB, Adams JH, Carvalho LH, Kano FS. Antibody response to a new member of the DBL family (EBP2) after a brief Plasmodium vivax exposure. PLoS Negl Trop Dis 2022; 16:e0010493. [PMID: 35714097 PMCID: PMC9205486 DOI: 10.1371/journal.pntd.0010493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 05/12/2022] [Indexed: 12/03/2022] Open
Abstract
Plasmodium vivax blood-stage invasion into reticulocyte is critical for parasite development. Thus, validation of novel parasite invasion ligands is essential for malaria vaccine development. Recently, we demonstrated that EBP2, a Duffy binding protein (DBP) paralog, is antigenically distinct from DBP and could not be functionally inhibited by anti-DBP antibodies. Here, we took advantage of a small outbreak of P.vivax malaria, located in a non-malarious area of Brazil, to investigate for the first time IgM/IgG antibodies against EBP2 and DEKnull-2 (an engineering DBPII vaccine) among individuals who had their first and brief exposure to P.vivax (16 cases and 22 non-cases). Our experimental approach included 4 cross sectional surveys at 3-month interval (12-month follow-up). The results demonstrated that while a brief initial P.vivax infection was not efficient to induce IgM/ IgG antibodies to either EBP2 or DEKnull-2, IgG antibodies against DEKnull-2 (but not EBP2) were boosted by recurrent blood-stage infections following treatment. Of interest, in most recurrent P. vivax infections (4 out of 6 patients) DEKnull-2 IgG antibodies were sustained for 6 to 12 months. Polymorphisms in the ebp2 gene does not seem to explain EBP2 low immunogenicity as the ebp2 allele associated with the P.vivax outbreak presented high identity to the original EBP2 isolate used as recombinant protein. Although EBP2 antibodies were barely detectable after a primary episode of P.vivax infection, EBP2 was highly recognized by serum IgG from long-term malaria-exposed Amazonians (range from 35 to 92% according to previous malaria episodes). Taken together, the results showed that individuals with a single and brief exposure to P.vivax infection develop very low anti-EBP2 antibodies, which tend to increase after long-term malaria exposure. Finally, the findings highlighted the potential of DEKnull-2 as a vaccine candidate, as in non-immune individuals anti-DEKnull-2 IgG antibodies were boosted even after a brief exposure to P.vivax blood stages.
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Affiliation(s)
- Bárbara A. S. Lima
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Gabriela M. Fernandes
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Letícia M. Torres
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Camilla V. Pires
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Jéssica R. S. Alves
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Sâmick L. Moreira-Nascimento
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Maria Fernanda A. Nascimento
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Sofia L. Afonso
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Helena L. Costa
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Isabela P. Cerávolo
- Laboratório de Imunopatologia, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Tais N. Sousa
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Irene S. Soares
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, Brazil
| | - Francis B. Ntumngia
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - John H. Adams
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Luzia H. Carvalho
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
| | - Flora S. Kano
- Biologia Molecular e Imunologia da Malária, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
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13
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Hou MM, Barrett JR, Themistocleous Y, Rawlinson TA, Diouf A, Martinez FJ, Nielsen CM, Lias AM, King LDW, Edwards NJ, Greenwood NM, Kingham L, Poulton ID, Khozoee B, Goh C, Mac Lochlainn DJ, Salkeld J, Guilotte-Blisnick M, Huon C, Mohring F, Reimer JM, Chauhan VS, Mukherjee P, Biswas S, Taylor IJ, Lawrie AM, Cho JS, Nugent FL, Long CA, Moon RW, Miura K, Silk SE, Chitnis CE, Minassian AM, Draper SJ. Impact of a blood-stage vaccine on Plasmodium vivax malaria. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2022:2022.05.27.22275375. [PMID: 35664997 PMCID: PMC9164524 DOI: 10.1101/2022.05.27.22275375] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Background There are no licensed vaccines against Plasmodium vivax , the most common cause of malaria outside of Africa. Methods We conducted two Phase I/IIa clinical trials to assess the safety, immunogenicity and efficacy of two vaccines targeting region II of P. vivax Duffy-binding protein (PvDBPII). Recombinant viral vaccines (using ChAd63 and MVA vectors) were administered at 0, 2 months or in a delayed dosing regimen (0, 17, 19 months), whilst a protein/adjuvant formulation (PvDBPII/Matrix-M™) was administered monthly (0, 1, 2 months) or in a delayed dosing regimen (0, 1, 14 months). Delayed regimens were due to trial halts during the COVID-19 pandemic. Volunteers underwent heterologous controlled human malaria infection (CHMI) with blood-stage P. vivax parasites at 2-4 weeks following their last vaccination, alongside unvaccinated controls. Efficacy was assessed by comparison of parasite multiplication rate (PMR) in blood post-CHMI, modelled from parasitemia measured by quantitative polymerase-chain-reaction (qPCR). Results Thirty-two volunteers were enrolled and vaccinated (n=16 for each vaccine). No safety concerns were identified. PvDBPII/Matrix-M™, given in the delayed dosing regimen, elicited the highest antibody responses and reduced the mean PMR following CHMI by 51% (range 36-66%; n=6) compared to unvaccinated controls (n=13). No other vaccine or regimen impacted parasite growth. In vivo growth inhibition of blood-stage P. vivax correlated with functional antibody readouts of vaccine immunogenicity. Conclusions Vaccination of malaria-naïve adults with a delayed booster regimen of PvDBPII/ Matrix-M™ significantly reduces the growth of blood-stage P. vivax . Funded by the European Commission and Wellcome Trust; VAC069, VAC071 and VAC079 ClinicalTrials.gov numbers NCT03797989 , NCT04009096 and NCT04201431 .
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Affiliation(s)
- Mimi M Hou
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Jordan R Barrett
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | | | | | - Ababacar Diouf
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Francisco J Martinez
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Carolyn M Nielsen
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Amelia M Lias
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Lloyd D W King
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Nick J Edwards
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | | | - Lucy Kingham
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Ian D Poulton
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Baktash Khozoee
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Cyndi Goh
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Dylan J Mac Lochlainn
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Jo Salkeld
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Micheline Guilotte-Blisnick
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Christèle Huon
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Franziska Mohring
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | | | - Virander S Chauhan
- International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | | | - Sumi Biswas
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Iona J Taylor
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Alison M Lawrie
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Jee-Sun Cho
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Fay L Nugent
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Carole A Long
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Robert W Moon
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, WC1E 7HT, UK
| | - Kazutoyo Miura
- Laboratory of Malaria and Vector Research, NIAID/NIH, Rockville, MD 20852, USA
| | - Sarah E Silk
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Chetan E Chitnis
- Unité de Biologie de Plasmodium et Vaccins, Institut Pasteur, Université Paris Cité, 25-28 Rue du Dr Roux, 75015 Paris, France
| | - Angela M Minassian
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
| | - Simon J Draper
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
- The Jenner Institute, University of Oxford, Oxford, OX3 7DQ, UK
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14
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Alves JRS, de Araújo FF, Pires CV, Teixeira-Carvalho A, Lima BAS, Torres LM, Ntumngia FB, Adams JH, Kano FS, Carvalho LH. Multiplexed Microsphere-Based Flow Cytometric Assay to Assess Strain Transcending Antibodies to Plasmodium vivax Duffy Binding Protein II Reveals an Efficient Tool to Identify Binding-Inhibitory Antibody Responders. Front Immunol 2021; 12:704653. [PMID: 34675915 PMCID: PMC8523986 DOI: 10.3389/fimmu.2021.704653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/13/2021] [Indexed: 11/24/2022] Open
Abstract
Malaria remains a major public health problem worldwide, and Plasmodium vivax is the most widely distributed malaria parasite. Naturally acquired binding inhibitory antibodies (BIAbs) to region II of the Duffy binding protein (DBPII), a P. vivax ligand that is critical for reticulocyte invasion, are associated with a reduced risk of clinical malaria. Owing to methodological issues in evaluating antibodies that inhibit the DBPII-DARC interaction, a limited number of studies have investigated DBPII BIAbs in P. vivax-exposed populations. Based on the assumption that individuals with a consistent BIAb response are characterized by strain-transcending immune responses, we hypothesized that detecting broadly reactive DBPII antibodies would indicate the presence of BIAb response. By taking advantage of an engineered DBPII immunogen targeting conserved DBPII neutralizing epitopes (DEKnull-2), we standardized a multiplex flow cytometry-based serological assay to detect broadly neutralizing IgG antibodies. For this study, a standard in vitro cytoadherence assay with COS-7 cells expressing DBPII was used to test for DBPII BIAb response in long-term P. vivax-exposed Amazonian individuals. Taken together, the results demonstrate that this DBPII-based multiplex assay facilitates identifying DBPII BIAb carriers. Of relevance, the ability of the multiplex assay to identify BIAb responders was highly accurate when the positivity for all antigens was considered. In conclusion, the standardized DBPII-based flow cytometric assay confirmed that DBPII-BIAb activity was associated with the breadth rather than the magnitude of anti-DBPII antibodies. Altogether, our results suggest that multiplex detection of broadly DBPII-reactive antibodies facilitates preliminary screening of BIAb responders.
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Affiliation(s)
- Jéssica R. S. Alves
- Molecular Biology and Malaria Immunology, René Rachou Institute, Oswaldo Cruz Foundation (FIOCRUZ), Belo Horizonte, Brazil
| | - Fernanda F. de Araújo
- Integrated Research Group in Biomarkers, René Rachou Institute, Oswaldo Cruz Foundation (FIOCRUZ), Belo Horizonte, Brazil
| | - Camilla V. Pires
- Center for Global Health and Infectious Diseases Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, United States
| | - Andréa Teixeira-Carvalho
- Integrated Research Group in Biomarkers, René Rachou Institute, Oswaldo Cruz Foundation (FIOCRUZ), Belo Horizonte, Brazil
| | - Barbara A. S. Lima
- Molecular Biology and Malaria Immunology, René Rachou Institute, Oswaldo Cruz Foundation (FIOCRUZ), Belo Horizonte, Brazil
| | - Letícia M. Torres
- Molecular Biology and Malaria Immunology, René Rachou Institute, Oswaldo Cruz Foundation (FIOCRUZ), Belo Horizonte, Brazil
| | - Francis B. Ntumngia
- Center for Global Health and Infectious Diseases Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, United States
| | - John H. Adams
- Center for Global Health and Infectious Diseases Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, United States
| | - Flora S. Kano
- Molecular Biology and Malaria Immunology, René Rachou Institute, Oswaldo Cruz Foundation (FIOCRUZ), Belo Horizonte, Brazil
| | - Luzia H. Carvalho
- Molecular Biology and Malaria Immunology, René Rachou Institute, Oswaldo Cruz Foundation (FIOCRUZ), Belo Horizonte, Brazil
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Opi DH, Kurtovic L, Chan JA, Horton JL, Feng G, Beeson JG. Multi-functional antibody profiling for malaria vaccine development and evaluation. Expert Rev Vaccines 2021; 20:1257-1272. [PMID: 34530671 DOI: 10.1080/14760584.2021.1981864] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION A vaccine would greatly accelerate current global efforts toward malaria elimination. While a partially efficacious vaccine has been achieved for Plasmodium falciparum, a major bottleneck in developing highly efficacious vaccines is a lack of reliable correlates of protection, and the limited application of assays that quantify functional immune responses to evaluate and down-select vaccine candidates in pre-clinical studies and clinical trials. AREAS COVERED In this review, we describe the important role of antibodies in immunity against malaria and detail the nature and functional activities of antibodies against the malaria-causing parasite. We highlight the growing understanding of antibody effector functions against malaria and in vitro assays to measure these functional antibody responses. We discuss the application of these assays to quantify antibody functions in vaccine development and evaluation. EXPERT OPINION It is becoming increasingly clear that multiple antibody effector functions are involved in immunity to malaria. Therefore, we propose that evaluating vaccine candidates needs to move beyond individual assays or measuring IgG magnitude alone. Instead, vaccine evaluation should incorporate the full breadth of antibody response types and harness a wider range of assays measuring functional antibody responses. We propose a 3-tier approach to implementing assays to inform vaccine evaluation.
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Affiliation(s)
- D Herbert Opi
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Liriye Kurtovic
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia
| | - Jo-Anne Chan
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Jessica L Horton
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - Gaoqian Feng
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia
| | - James G Beeson
- Life Sciences, Burnet Institute, Melbourne, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, Australia.,Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, Australia.,Department of Microbiology, Monash University, Clayton, Australia
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16
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Pincelli A, Cardoso MA, Malta MB, Johansen IC, Corder RM, Nicolete VC, Soares IS, Castro MC, Ferreira MU. Low-level Plasmodium vivax exposure, maternal antibodies, and anemia in early childhood: Population-based birth cohort study in Amazonian Brazil. PLoS Negl Trop Dis 2021; 15:e0009568. [PMID: 34264946 PMCID: PMC8282015 DOI: 10.1371/journal.pntd.0009568] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Accepted: 06/16/2021] [Indexed: 11/26/2022] Open
Abstract
Background Malaria causes significant morbidity and mortality in children under 5 years of age in sub-Saharan Africa and the Asia-Pacific region. Neonates and young infants remain relatively protected from clinical disease and the transplacental transfer of maternal antibodies is hypothesized as one of the protective factors. The adverse health effects of Plasmodium vivax malaria in early childhood–traditionally viewed as a benign infection–remain largely neglected in relatively low-endemicity settings across the Amazon. Methodology/Principal findings Overall, 1,539 children participating in a birth cohort study in the main transmission hotspot of Amazonian Brazil had a questionnaire administered, and blood sampled at the two-year follow-up visit. Only 7.1% of them experienced malaria confirmed by microscopy during their first 2 years of life– 89.1% of the infections were caused by P. vivax. Young infants appear to be little exposed to, or largely protected from infection, but children >12 months of age become as vulnerable to vivax malaria as their mothers. Few (1.4%) children experienced ≥4 infections during the 2-year follow-up, accounting for 43.4% of the overall malaria burden among study participants. Antenatal malaria diagnosed by microscopy during pregnancy or by PCR at delivery emerged as a significant correlate of subsequent risk of P. vivax infection in the offspring (incidence rate ratio, 2.58; P = 0.002), after adjusting for local transmission intensity. Anti-P. vivax antibodies measured at delivery do not protect mothers from subsequent malaria; whether maternal antibodies transferred to the fetus reduce early malaria risk in children remains undetermined. Finally, recent and repeated vivax malaria episodes in early childhood are associated with increased risk of anemia at the age of 2 years in this relatively low-endemicity setting. Conclusions/Significance Antenatal infection increases the risk of vivax malaria in the offspring and repeated childhood P. vivax infections are associated with anemia at the age of 2 years. Plasmodium vivax malaria causes frequent hospital admissions of infants and toddlers in areas of intense transmission in the Asia-Pacific region, often due to severe anemia, but its epidemiology and burden have been understudied in children from other endemic settings. Here we characterize the cumulative impact of P. vivax infections in infants and toddlers exposed to relatively low levels of malaria transmission in the Brazilian Amazon. We have previously shown that vivax malaria in pregnancy is associated with increased risk of maternal anemia and impaired fetal growth in this population. Now we show that the adverse effects of malaria extend to early childhood. Children born to mothers who had one or more infections during pregnancy are at an elevated risk of P. vivax malaria in their early life, although the transfer of maternal antibodies to the fetus may provide some short-term protection. Children who are repeatedly infected with P. vivax since birth are more likely to be anemic at the age of 2 years. These findings further challenge the traditional view of vivax malaria as a relatively benign infection in pregnancy and early childhood in the Amazon.
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Affiliation(s)
- Anaclara Pincelli
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Marly A. Cardoso
- Department of Nutrition, School of Public Health, University of São Paulo, São Paulo, Brazil
| | - Maíra B. Malta
- Department of Nutrition, School of Public Health, University of São Paulo, São Paulo, Brazil
- Graduate Program in Collective Health, Catholic University of Santos, Santos, Brazil
| | - Igor C. Johansen
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rodrigo M. Corder
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Vanessa C. Nicolete
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Irene S. Soares
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Marcia C. Castro
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
| | - Marcelo U. Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail:
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Yuguchi T, Kanoi BN, Nagaoka H, Miura T, Ito D, Takeda H, Tsuboi T, Takashima E, Otsuki H. Plasmodium yoelii Erythrocyte Binding Like Protein Interacts With Basigin, an Erythrocyte Surface Protein. Front Cell Infect Microbiol 2021; 11:656620. [PMID: 33937099 PMCID: PMC8079763 DOI: 10.3389/fcimb.2021.656620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/25/2021] [Indexed: 11/30/2022] Open
Abstract
Erythrocyte recognition and invasion is critical for the intra-erythrocytic development of Plasmodium spp. parasites. The multistep invasion process involves specific interactions between parasite ligands and erythrocyte receptors. Erythrocyte-binding-like (EBL) proteins, type I integral transmembrane proteins released from the merozoite micronemes, are known to play an important role in the initiation and formation of tight junctions between the apical end of the merozoite and the erythrocyte surface. In Plasmodium yoelii EBL (PyEBL), a single amino acid substitution in the putative Duffy binding domain dramatically changes parasite growth rate and virulence. This suggests that PyEBL is important for modulating the virulence of P. yoelii parasites. Based on these observations, we sought to elucidate the receptor of PyEBL that mediates its role as an invasion ligand. Using the eukaryotic wheat germ cell-free system, we systematically developed and screened a library of mouse erythrocyte proteins against native PyEBL using AlphaScreen technology. We report that PyEBL specifically interacts with basigin, an erythrocyte surface protein. We further confirmed that the N-terminal cysteine-rich Duffy binding-like region (EBL region 2), is responsible for the interaction, and that the binding is not affected by the C351Y mutation, which was previously shown to modulate virulence of P. yoelii. The identification of basigin as the putative PyEBL receptor offers new insights into the role of this molecule and provides an important base for in-depth studies towards developing novel interventions against malaria.
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Affiliation(s)
- Takaaki Yuguchi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Bernard N Kanoi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Hikaru Nagaoka
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Toyokazu Miura
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Daisuke Ito
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
| | - Hiroyuki Takeda
- Division of Proteo-Drug-Discovery Sciences, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Eizo Takashima
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Japan
| | - Hitoshi Otsuki
- Division of Medical Zoology, Department of Microbiology and Immunology, Faculty of Medicine, Tottori University, Yonago, Japan
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18
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De SL, Ntumngia FB, Nicholas J, Adams JH. Progress towards the development of a P. vivax vaccine. Expert Rev Vaccines 2021; 20:97-112. [PMID: 33481638 PMCID: PMC7994195 DOI: 10.1080/14760584.2021.1880898] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 01/21/2021] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Plasmodium vivax causes significant public health problems in endemic regions. A vaccine to prevent disease is critical, considering the rapid spread of drug-resistant parasite strains, and the development of hypnozoites in the liver with potential for relapse. A minimally effective vaccine should prevent disease and transmission while an ideal vaccine provides sterile immunity. AREAS COVERED Despite decades of research, the complex life cycle, technical challenges and a lack of funding have hampered progress of P. vivax vaccine development. Here, we review the progress of potential P. vivax vaccine candidates from different stages of the parasite life cycle. We also highlight the challenges and important strategies for rational vaccine design. These factors can significantly increase immune effector mechanisms and improve the protective efficacy of these candidates in clinical trials to generate sustained protection over longer periods of time. EXPERT OPINION A vaccine that presents functionally-conserved epitopes from multiple antigens from various stages of the parasite life cycle is key to induce broadly neutralizing strain-transcending protective immunity to effectively disrupt parasite development and transmission.
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Affiliation(s)
- Sai Lata De
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, 3720 Spectrum Blvd, Tampa – 33612, FL
| | - Francis B. Ntumngia
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, 3720 Spectrum Blvd, Tampa – 33612, FL
| | - Justin Nicholas
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, 3720 Spectrum Blvd, Tampa – 33612, FL
| | - John H. Adams
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, 3720 Spectrum Blvd, Tampa – 33612, FL
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19
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Hotspots in Plasmodium and RBC Receptor-Ligand Interactions: Key Pieces for Inhibiting Malarial Parasite Invasion. Int J Mol Sci 2020; 21:ijms21134729. [PMID: 32630804 PMCID: PMC7370042 DOI: 10.3390/ijms21134729] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/15/2020] [Accepted: 05/24/2020] [Indexed: 11/17/2022] Open
Abstract
Protein-protein interactions (IPP) play an essential role in practically all biological processes, including those related to microorganism invasion of their host cells. It has been found that a broad repertoire of receptor-ligand interactions takes place in the binding interphase with host cells in malaria, these being vital interactions for successful parasite invasion. Several trials have been conducted for elucidating the molecular interface of interactions between some Plasmodium falciparum and Plasmodium vivax antigens with receptors on erythrocytes and/or reticulocytes. Structural information concerning these complexes is available; however, deeper analysis is required for correlating structural, functional (binding, invasion, and inhibition), and polymorphism data for elucidating new interaction hotspots to which malaria control methods can be directed. This review describes and discusses recent structural and functional details regarding three relevant interactions during erythrocyte invasion: Duffy-binding protein 1 (DBP1)–Duffy antigen receptor for chemokines (DARC); reticulocyte-binding protein homolog 5 (PfRh5)-basigin, and erythrocyte binding antigen 175 (EBA175)-glycophorin A (GPA).
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20
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Medeiros CMP, Moreira EUM, Pires CV, Torres LM, Guimarães LFF, Alves JRS, Lima BAS, Fontes CJF, Costa HL, Brito CFA, Sousa TN, Ntumngia FB, Adams JH, Kano FS, Carvalho LH. Dynamics of IgM and IgG responses to the next generation of engineered Duffy binding protein II immunogen: Strain-specific and strain-transcending immune responses over a nine-year period. PLoS One 2020; 15:e0232786. [PMID: 32379804 PMCID: PMC7205269 DOI: 10.1371/journal.pone.0232786] [Citation(s) in RCA: 4] [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: 01/27/2020] [Accepted: 04/21/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND A low proportion of P. vivax-exposed individuals acquire protective strain-transcending neutralizing IgG antibodies that are able to block the interaction between the Duffy binding protein II (DBPII) and its erythrocyte-specific invasion receptor. In a recent study, a novel surface-engineered DBPII-based vaccine termed DEKnull-2, whose antibody response target conserved DBPII epitopes, was able to induce broadly binding-inhibitory IgG antibodies (BIAbs) that inhibit P. vivax reticulocyte invasion. Toward the development of DEKnull-2 as an effective P. vivax blood-stage vaccine, we investigate the relationship between naturally acquired DBPII-specific IgM response and the profile of IgG antibodies/BIAbs activity over time. METHODOLOGY/PRINCIPAL FINDINGS A nine-year follow-up study was carried-out among long-term P. vivax-exposed Amazonian individuals and included six cross-sectional surveys at periods of high and low malaria transmission. DBPII immune responses associated with either strain-specific (Sal1, natural DBPII variant circulating in the study area) or conserved epitopes (DEKnull-2) were monitored by conventional serology (ELISA-detected IgM and IgG antibodies), with IgG BIAbs activity evaluated by functional assays (in vitro inhibition of DBPII-erythrocyte binding). The results showed a tendency of IgM antibodies toward Sal1-specific response; the profile of Sal1 over DEKnull-2 was not associated with acute malaria and sustained throughout the observation period. The low malaria incidence in two consecutive years allowed us to demonstrate that variant-specific IgG (but not IgM) antibodies waned over time, which resulted in IgG skewed to the DEKnull-2 response. A persistent DBPII-specific IgM response was not associated with the presence (or absence) of broadly neutralizing IgG antibody response. CONCLUSIONS/SIGNIFICANCE The current study demonstrates that long-term exposure to low and unstable levels of P. vivax transmission led to a sustained DBPII-specific IgM response against variant-specific epitopes, while sustained IgG responses are skewed to conserved epitopes. Further studies should investigate on the role of a stable and persistent IgM antibody response in the immune response mediated by DBPII.
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Affiliation(s)
- Camila M. P. Medeiros
- Centro de Pesquisas René Rachou/FIOCRUZ Minas, Belo Horizonte, MG, Brazil
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | - Camilla V. Pires
- Centro de Pesquisas René Rachou/FIOCRUZ Minas, Belo Horizonte, MG, Brazil
| | - Letícia M. Torres
- Centro de Pesquisas René Rachou/FIOCRUZ Minas, Belo Horizonte, MG, Brazil
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | | | | | - Bárbara A. S. Lima
- Centro de Pesquisas René Rachou/FIOCRUZ Minas, Belo Horizonte, MG, Brazil
| | - Cor J. F. Fontes
- Hospital Júlio Muller, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Helena L. Costa
- Centro de Pesquisas René Rachou/FIOCRUZ Minas, Belo Horizonte, MG, Brazil
| | | | - Tais N. Sousa
- Centro de Pesquisas René Rachou/FIOCRUZ Minas, Belo Horizonte, MG, Brazil
| | - Francis B. Ntumngia
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - John H. Adams
- Center for Global Health and Infectious Diseases Research, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Flora S. Kano
- Centro de Pesquisas René Rachou/FIOCRUZ Minas, Belo Horizonte, MG, Brazil
- * E-mail: (LHC); (FSK)
| | - Luzia H. Carvalho
- Centro de Pesquisas René Rachou/FIOCRUZ Minas, Belo Horizonte, MG, Brazil
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
- * E-mail: (LHC); (FSK)
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Imported Malaria in Countries where Malaria Is Not Endemic: a Comparison of Semi-immune and Nonimmune Travelers. Clin Microbiol Rev 2020; 33:33/2/e00104-19. [PMID: 32161068 DOI: 10.1128/cmr.00104-19] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The continuous increase in long-distance travel and recent large migratory movements have changed the epidemiological characteristics of imported malaria in countries where malaria is not endemic (here termed non-malaria-endemic countries). While malaria was primarily imported to nonendemic countries by returning travelers, the proportion of immigrants from malaria-endemic regions and travelers visiting friends and relatives (VFRs) in malaria-endemic countries has continued to increase. VFRs and immigrants from malaria-endemic countries now make up the majority of malaria patients in many nonendemic countries. Importantly, this group is characterized by various degrees of semi-immunity to malaria, resulting from repeated exposure to infection and a gradual decline of protection as a result of prolonged residence in non-malaria-endemic regions. Most studies indicate an effect of naturally acquired immunity in VFRs, leading to differences in the parasitological features, clinical manifestation, and odds for severe malaria and clinical complications between immune VFRs and nonimmune returning travelers. There are no valid data indicating evidence for differing algorithms for chemoprophylaxis or antimalarial treatment in semi-immune versus nonimmune malaria patients. So far, no robust biomarkers exist that properly reflect anti-parasite or clinical immunity. Until they are found, researchers should rigorously stratify their study results using surrogate markers, such as duration of time spent outside a malaria-endemic country.
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Amplification of Duffy binding protein-encoding gene allows Plasmodium vivax to evade host anti-DBP humoral immunity. Nat Commun 2020; 11:953. [PMID: 32075983 PMCID: PMC7031336 DOI: 10.1038/s41467-020-14574-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 01/18/2020] [Indexed: 01/02/2023] Open
Abstract
Antigenic variation, the capacity to produce a range of variable antigens, is a well-described strategy of Plasmodium and other parasites to evade host immunity. Here, we show that gene amplification is an additional evasion mechanism used by Plasmodium vivax to escape humoral immunity targeting PvDBP, the key ligand involved in reticulocyte invasion. PvDBP gene amplification leads to increased mRNA levels and protects P. vivax in vitro against invasion inhibitory human monoclonal antibodies targeting a conserved binding domain of DBP. Patient samples suggest that parasites with increased pvdbp copy number are able to infect individuals with naturally acquired antibodies highly blocking the binding of PvDBP to the Duffy receptor. These results show that gene copy number variation affect the parasite’s ability to evade anti-PvDBP humoral immunity. Duffy binding protein (DBP) of Plasmodium vivax is important for invasion and is a potential vaccine candidate. Here, the authors show that PvDBP gene amplification protects P vivax in vitro against invasion inhibitory human monoclonal antibodies and is associated to infection of patients with PvDBP binding inhibitory antibodies.
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23
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Kochayoo P, Changrob S, Wangriatisak K, Lee SK, Chootong P, Han ET. The persistence of naturally acquired antibodies and memory B cells specific to rhoptry proteins of Plasmodium vivax in patients from areas of low malaria transmission. Malar J 2019; 18:382. [PMID: 31783870 PMCID: PMC6884809 DOI: 10.1186/s12936-019-3009-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 11/16/2019] [Indexed: 01/07/2023] Open
Abstract
Background Rhoptries are the large, paired, secretory organelles located at the apical tip of the malaria merozoite that are considered important for parasite invasion processes. Plasmodium vivax rhoptry proteins have been shown to induce humoral immunity during natural infections. Therefore, these proteins may be potential novel vaccine candidates. However, there is a lack of data on the duration of antibody and memory B cell (MBC) responses. Here, the longitudinal analysis of antibody and MBC responses to the P. vivax rhoptry proteins PvRALP1-Ecto and PvRhopH2 were monitored and analysed in individuals to determine their persistence. Methods Thirty-nine samples from P. vivax-infected subjects (age 18–60 years) were recruited to explore the frequency and persistence of antibody and MBC responses against rhoptry proteins (PvRALP1-Ecto and PvRhopH2) using both cross-sectional and longitudinal cohort study designs. Antibody levels were determined by ELISA during clinical malaria, and at 3, 9 and 12 months post-infection. The frequency of MBC sub-sets and presence of rhoptry-specific MBCs in subjects 18 months after treatment were detected by flow cytometry and ELISPOT assay. Results The seroprevalence of antibodies against PvRALP1-Ecto and PvRhopH2 proteins was found to be high during acute infection, with IgG1, IgG2 and IgG3 sub-classes predominant. However, these anti-rhoptry responses were short-lived and significantly decreased at 9 months post-infection. To relate the durability of these antibody responses to MBC persistence at post-infection, 18-month post-infection peripheral blood mononuclear cells (PBMCs) samples were taken to detect rhoptry-specific MBCs and frequency of MBC sub-sets, and correlate with antibody responses. These late post-infection samples revealed that rhoptry-specific MBCs were present in about 70% of total subjects. However, the persistence of specific MBCs was not correlated with antibody responses as the majority of malaria subjects who were positive for PvRALP1-Ecto- or PvRhopH2-specific MBCs were seronegative for the rhoptry antigens. The frequencies of classical MBCs were increased after infection, whereas those of activated and atypical MBCs were decreased, indicating that MBC responses could switch from activated or atypical MBCs to classical MBCs after parasite clearance, and were maintained in blood circulating at post-infection. Conclusion The study showed that rhoptry antigens induced the development and persistence of MBC responses in P. vivax-infected subjects who lived in a region of low malaria transmission, which were not related to the longevity of antibody responses.
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Affiliation(s)
- Piyawan Kochayoo
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand
| | - Siriruk Changrob
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand
| | - Kittikorn Wangriatisak
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand
| | - Seong Kyun Lee
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea
| | - Patchanee Chootong
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand.
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea.
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24
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Hu Y, Wang L, Mbenda HGN, Soe MT, Yu C, Feng H, Kyaw MP, Cui L, Zhu X, Cao Y. Genetic diversity, natural selection and haplotype grouping of Plasmodium vivax Duffy-binding protein genes from eastern and western Myanmar borders. Parasit Vectors 2019; 12:546. [PMID: 31747970 PMCID: PMC6864963 DOI: 10.1186/s13071-019-3803-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/12/2019] [Indexed: 12/17/2022] Open
Abstract
Background Merozoite proteins of the malaria parasites involved in the invasion of red blood cells are selected by host immunity and their diversity is greatly influenced by changes in malaria epidemiology. In the Greater Mekong Subregion (GMS), malaria transmission is concentrated along the international borders and there have been major changes in malaria epidemiology with Plasmodium vivax becoming the dominant species in many regions. Here, we aimed to evaluate the genetic diversity of P. vivax Duffy-binding protein gene domain II (pvdbp-II) in isolates from the eastern and western borders of Myanmar, and compared it with that from global P. vivax populations. Methods pvdbp-II sequences were obtained from 85 and 82 clinical P. vivax isolates from the eastern and western Myanmar borders, respectively. In addition, 504 pvdbp-II sequences from nine P. vivax populations of the world were retrieved from GenBank and used for comparative analysis of genetic diversity, recombination and population structure of the parasite population. Results The nucleotide diversity of the pvdbp-II sequences from the Myanmar border parasite isolates was not uniform, with the highest diversity located between nucleotides 1078 and 1332. Western Myanmar isolates had a unique R391C mutation. Evidence of positive natural selection was detected in pvdbp-II gene in P. vivax isolates from the eastern Myanmar area. P. vivax parasite populations in the GMS, including those from the eastern, western, and central Myanmar as well as Thailand showed low-level genetic differentiation (FST, 0.000–0.099). Population genetic structure analysis of the pvdbp-II sequences showed a division of the GMS populations into four genetic clusters. A total of 60 PvDBP-II haplotypes were identified in 210 sequences from the GMS populations. Among the epitopes in PvDBP-II, high genetic diversity was found in epitopes 45 (379-SIFGT(D/G)(E/K)(K/N)AQQ(R/H)(R/C)KQ-393, π = 0.029) and Ia (416-G(N/K)F(I/M)WICK(L/I)-424], Ib [482-KSYD(Q/E)WITR-490, π = 0.028) in P. vivax populations from the eastern and western borders of Myanmar. Conclusions The pvdbp-II gene is genetically diverse in the eastern and western Myanmar border P. vivax populations. Positive natural selection and recombination occurred in pvdbp-II gene. Low-level genetic differentiation was identified, suggesting extensive gene flow of the P. vivax populations in the GMS. These results can help understand the evolution of the P. vivax populations in the course of regional malaria elimination and guide the design of PvDBP-II-based vaccine.![]()
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Affiliation(s)
- Yubing Hu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Lin Wang
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Huguette Gaelle Ngassa Mbenda
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Myat Thu Soe
- Myanmar Health Network Organization, Yangon, Myanmar
| | - Chunyun Yu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | - Hui Feng
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China
| | | | - Liwang Cui
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, 3720 Spectrum Boulevard, Suite 304, Tampa, FL, 33612, USA
| | - Xiaotong Zhu
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China.
| | - Yaming Cao
- Department of Immunology, College of Basic Medical Science, China Medical University, Shenyang, 110122, Liaoning, China.
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25
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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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26
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Ntumngia FB, Thomson-Luque R, Galusic S, Frato G, Frischmann S, Peabody DS, Chackerian B, Ferreira MU, King CL, Adams JH. Identification and Immunological Characterization of the Ligand Domain of Plasmodium vivax Reticulocyte Binding Protein 1a. J Infect Dis 2019; 218:1110-1118. [PMID: 29741629 DOI: 10.1093/infdis/jiy273] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/04/2018] [Indexed: 02/02/2023] Open
Abstract
Background Erythrocyte invasion by malaria parasites is essential for blood-stage development. Consequently, parasite proteins critically involved in erythrocyte invasion, such as the Plasmodium vivax reticulocyte binding proteins (RBPs) that mediate preferential invasion of reticulocytes, are considered potential vaccine targets. Thus, targeting the RBPs could prevent blood-stage infection and disease. The RBPs are large, and little is known about their functional domains and whether individuals naturally exposed to P. vivax acquire binding-inhibitory antibodies to these critical binding regions. This study aims to functionally and immunologically characterize Plasmodium vivax RBP1a. Methods Recombinant proteins of overlapping fragments of RBP1a were used to determine binding specificity to erythrocytes and immunogenicity in laboratory animals. The naturally acquired antibody response to these proteins was evaluated using serum samples from individuals in regions of endemicity. Results The N-terminal extracellular region, RBP1157-650 (RBP1:F8), was determined to bind both reticulocytes and normocytes, with a preference for immature reticulocytes. Antibodies elicited against rRBP1:F8 blocked binding between RBP1:F8 and erythrocytes. Naturally acquired anti-RBP1 binding-inhibitory antibodies were detected in serum specimens from P. vivax-exposed individuals from Papua New Guinea and Brazil. Conclusion Recombinant RBP1:F8 binds human erythrocytes, elicits artificially induced functional blocking antibodies, and is a target of naturally acquired binding-inhibitory antibodies.
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Affiliation(s)
- Francis B Ntumngia
- Center for Global Health and Infectious Diseases Research, University of South Florida, Tampa, FL
| | - Richard Thomson-Luque
- Center for Global Health and Infectious Diseases Research, University of South Florida, Tampa, FL
| | - Sandra Galusic
- Center for Global Health and Infectious Diseases Research, University of South Florida, Tampa, FL
| | - Gabriel Frato
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH
| | - Sarah Frischmann
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH
| | - David S Peabody
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM
| | - Bryce Chackerian
- Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM
| | - Marcelo U Ferreira
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, Brazil
| | - Christopher L King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH
| | - John H Adams
- Center for Global Health and Infectious Diseases Research, University of South Florida, Tampa, FL
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27
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Soares RR, Cunha CF, Ferraz‐Nogueira R, Marins‐dos‐Santos A, Rodrigues‐da‐Silva RN, Soares I, Lima‐Junior J, Bertho AL, Ferreira MU, Scopel KKG. Apical membrane protein 1‐specific antibody profile and temporal changes in peripheral blood B‐cell populations in
Plasmodium vivax
malaria. Parasite Immunol 2019; 41:e12662. [DOI: 10.1111/pim.12662] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 06/07/2019] [Accepted: 07/01/2019] [Indexed: 02/03/2023]
Affiliation(s)
- Roberta Reis Soares
- Department of Parasitology, Microbiology and Immunology Institute of Biological Sciences, Federal University of Juiz de Fora Juiz de Fora Brazil
| | - Clarissa F. Cunha
- Laboratory of Immunoparasitology Oswaldo Cruz Institute, FIOCRUZ Rio de Janeiro Brazil
| | - Raquel Ferraz‐Nogueira
- Laboratory of Immunoparasitology Oswaldo Cruz Institute, FIOCRUZ Rio de Janeiro Brazil
- Flow Cytometry Cell Sorting Core Facility Oswaldo Cruz Institute, FIOCRUZ Rio de Janeiro Brazil
| | | | | | - Irene Soares
- School of Pharmaceutical Sciences, Department of Clinical Analyses and Toxicology University of São Paulo Sao Paulo Brazil
| | - Josué Lima‐Junior
- Laboratory of Immunoparasitology Oswaldo Cruz Institute, FIOCRUZ Rio de Janeiro Brazil
| | - Alvaro Luiz Bertho
- Laboratory of Immunoparasitology Oswaldo Cruz Institute, FIOCRUZ Rio de Janeiro Brazil
- Flow Cytometry Cell Sorting Core Facility Oswaldo Cruz Institute, FIOCRUZ Rio de Janeiro Brazil
| | - Marcelo Urbano Ferreira
- Department of Parasitology, Institute of Biomedical Sciences University of São Paulo Sao Paulo Brazil
| | - Kézia Katiani Gorza Scopel
- Department of Parasitology, Microbiology and Immunology Institute of Biological Sciences, Federal University of Juiz de Fora Juiz de Fora Brazil
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28
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Urusova D, Carias L, Huang Y, Nicolete VC, Popovici J, Roesch C, Salinas ND, Dechavanne S, Witkowski B, Ferreira MU, Adams JH, Gross ML, King CL, Tolia NH. Structural basis for neutralization of Plasmodium vivax by naturally acquired human antibodies that target DBP. Nat Microbiol 2019; 4:1486-1496. [PMID: 31133752 PMCID: PMC6707876 DOI: 10.1038/s41564-019-0461-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 04/16/2019] [Indexed: 12/21/2022]
Abstract
The Plasmodium vivax Duffy binding protein (DBP) is a prime target of the protective immune response and a promising vaccine candidate for P. vivax malaria. Naturally acquired immunity (NAI) protects against malaria in adults residing in infection-endemic regions, and the passive transfer of malarial immunity confers protection. A vaccine that replicates NAI will effectively prevent disease. Here, we report the structures of DBP region II in complex with human-derived, neutralizing monoclonal antibodies obtained from an individual in a malaria-endemic area with naturally acquired immunity. We identified protective epitopes by X-ray crystallography, hydrogen-deuterium exchange mass spectrometry, mutational mapping, and P. vivax invasion studies. These approaches reveal that naturally-acquired human antibodies neutralize P. vivax by targeting the DARC–binding site and dimer interface of P. vivax DBP. Antibody binding is unaffected by polymorphisms in the vicinity of epitopes, suggesting the antibodies have evolved to engage multiple polymorphic variants of DBP. The human antibody epitopes are broadly conserved and are distinct from previously defined epitopes for broadly conserved murine mAbs. A library of globally conserved epitopes of neutralizing human antibodies opens new horizons for rational design of strain-transcending DBP-based vaccines and therapeutics against P. vivax.
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Affiliation(s)
- Darya Urusova
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Lenore Carias
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Yining Huang
- Department of Chemistry, Washington University in St Louis, St Louis, MO, USA.,Bioproduct Research and Development, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | | | - Jean Popovici
- Malaria Molecular Epidemiology Unit, Pasteur Institute in Cambodia, Phnom Penh, Cambodia
| | - Camille Roesch
- Malaria Molecular Epidemiology Unit, Pasteur Institute in Cambodia, Phnom Penh, Cambodia
| | - Nichole D Salinas
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Sebastien Dechavanne
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Pasteur Institute in Cambodia, Phnom Penh, Cambodia
| | | | - John H Adams
- Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St Louis, St Louis, MO, USA
| | - Christopher L King
- Center for Global Health and Diseases, Case Western Reserve University, Cleveland, OH, USA
| | - Niraj H Tolia
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, USA. .,Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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29
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Structural basis for inhibition of Plasmodium vivax invasion by a broadly neutralizing vaccine-induced human antibody. Nat Microbiol 2019; 4:1497-1507. [PMID: 31133755 PMCID: PMC6711757 DOI: 10.1038/s41564-019-0462-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 04/16/2019] [Indexed: 12/21/2022]
Abstract
The most widespread form of malaria is caused by Plasmodium vivax. To replicate, this parasite must invade immature red blood cells, through a process which requires interaction of the Plasmodium vivax Duffy binding protein, PvDBP with its human receptor, the Duffy antigen receptor for chemokines, DARC. Naturally acquired antibodies that inhibit this interaction associate with clinical immunity, suggesting PvDBP as a leading candidate for inclusion in a vaccine to prevent malaria due to Plasmodium vivax. Here, we isolated a panel of monoclonal antibodies from human volunteers immunised in a clinical vaccine trial of PvDBP. We screened their ability to prevent PvDBP from binding to DARC, and their capacity to block red blood cell invasion by a transgenic Plasmodium knowlesi parasite genetically modified to express PvDBP and to prevent reticulocyte invasion by multiple clinical isolates of Plasmodium vivax. This identified a broadly neutralising human monoclonal antibody which inhibited invasion of all tested strains of Plasmodium vivax. Finally, we determined the structure of a complex of this antibody bound to PvDBP, indicating the molecular basis for inhibition. These findings will guide future vaccine design strategies and open up possibilities for testing the prophylactic use of such an antibody.
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30
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Salinas ND, Tang WK, Tolia NH. Blood-Stage Malaria Parasite Antigens: Structure, Function, and Vaccine Potential. J Mol Biol 2019; 431:4259-4280. [PMID: 31103771 DOI: 10.1016/j.jmb.2019.05.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 04/22/2019] [Accepted: 05/08/2019] [Indexed: 10/26/2022]
Abstract
Plasmodium parasites are the causative agent of malaria, a disease that kills approximately 450,000 individuals annually, with the majority of deaths occurring in children under the age of 5 years and the development of a malaria vaccine is a global health priority. Plasmodium parasites undergo a complex life cycle requiring numerous diverse protein families. The blood stage of parasite development results in the clinical manifestation of disease. A vaccine that disrupts the blood stage is highly desired and will aid in the control of malaria. The blood stage comprises multiple steps: invasion of, asexual growth within, and egress from red blood cells. This review focuses on blood-stage antigens with emphasis on antigen structure, antigen function, neutralizing antibodies, and vaccine potential.
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Affiliation(s)
- Nichole D Salinas
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD,, 20892, USA
| | - Wai Kwan Tang
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD,, 20892, USA
| | - Niraj H Tolia
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD,, 20892, USA.
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31
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Carias LL, Dechavanne S, Nicolete VC, Sreng S, Suon S, Amaratunga C, Fairhurst RM, Dechavanne C, Barnes S, Witkowski B, Popovici J, Roesch C, Chen E, Ferreira MU, Tolia NH, Adams JH, King CL. Identification and Characterization of Functional Human Monoclonal Antibodies to Plasmodium vivax Duffy-Binding Protein. THE JOURNAL OF IMMUNOLOGY 2019; 202:2648-2660. [PMID: 30944159 DOI: 10.4049/jimmunol.1801631] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 02/22/2019] [Indexed: 01/25/2023]
Abstract
Plasmodium vivax invasion of reticulocytes relies on distinct receptor-ligand interactions between the parasite and host erythrocytes. Engagement of the highly polymorphic domain II of the P. vivax Duffy-binding protein (DBPII) with the erythrocyte's Duffy Ag receptor for chemokines (DARC) is essential. Some P. vivax-exposed individuals acquired Abs to DBPII that block DBPII-DARC interaction and inhibit P. vivax reticulocyte invasion, and Ab levels correlate with protection against P. vivax malaria. To better understand the functional characteristics and fine specificity of protective human Abs to DBPII, we sorted single DBPII-specific IgG+ memory B cells from three individuals with high blocking activity to DBPII. We identified 12 DBPII-specific human mAbs from distinct lineages that blocked DBPII-DARC binding. All mAbs were P. vivax strain transcending and targeted known binding motifs of DBPII with DARC. Eleven mAbs competed with each other for binding, indicating recognition of the same or overlapping epitopes. Naturally acquired blocking Abs to DBPII from individuals with high levels residing in different P. vivax-endemic areas worldwide competed with mAbs, suggesting broadly shared recognition sites. We also found that mAbs inhibited P. vivax entry into reticulocytes in vitro. These findings suggest that IgG+ memory B cell activity in individuals with P. vivax strain-transcending Abs to DBPII display a limited clonal response with inhibitory blocking directed against a distinct region of the molecule.
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Affiliation(s)
- Lenore L Carias
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Sebastien Dechavanne
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106
| | - Vanessa C Nicolete
- Department of Parasitology, University of Sao Paulo, 05508-000 Sao Paulo, Brazil
| | - Sokunthea Sreng
- National Center for Parasitology, Entomology and Malaria Control, 12101 Phnom Penh, Cambodia
| | - Seila Suon
- National Center for Parasitology, Entomology and Malaria Control, 12101 Phnom Penh, Cambodia
| | - Chanaki Amaratunga
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Rick M Fairhurst
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Celia Dechavanne
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106.,UMR 261-Mother and Child Facing Tropical Infections, French National Research Institute for Development, Paris Descartes University, 75006 Paris, France
| | - Samantha Barnes
- Center for Global Health and Infectious Diseases Research, Department of Global Health, University of South Florida, Tampa, FL 33612
| | - Benoit Witkowski
- Malaria Unit, Pasteur Institute in Cambodia, 12201 Phnom Penh, Cambodia
| | - Jean Popovici
- Malaria Unit, Pasteur Institute in Cambodia, 12201 Phnom Penh, Cambodia
| | - Camille Roesch
- Malaria Unit, Pasteur Institute in Cambodia, 12201 Phnom Penh, Cambodia
| | - Edwin Chen
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110.,Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO 63110
| | - Marcelo U Ferreira
- Department of Parasitology, University of Sao Paulo, 05508-000 Sao Paulo, Brazil
| | - Niraj H Tolia
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110.,Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; and
| | - John H Adams
- Center for Global Health and Infectious Diseases Research, Department of Global Health, University of South Florida, Tampa, FL 33612
| | - Christopher L King
- Center for Global Health and Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106; .,Cleveland VA Medical Center, Cleveland, OH 44106
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32
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Antibody responses to Plasmodium vivax Duffy binding and Erythrocyte binding proteins predict risk of infection and are associated with protection from clinical Malaria. PLoS Negl Trop Dis 2019; 13:e0006987. [PMID: 30768655 PMCID: PMC6400399 DOI: 10.1371/journal.pntd.0006987] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 03/05/2019] [Accepted: 11/12/2018] [Indexed: 01/05/2023] Open
Abstract
Background The Plasmodium vivax Duffy Binding Protein (PvDBP) is a key target of naturally acquired immunity. However, region II of PvDBP, which contains the receptor-binding site, is highly polymorphic. The natural acquisition of antibodies to different variants of PvDBP region II (PvDBPII), including the AH, O, P and Sal1 alleles, the central region III-V (PvDBPIII-V), and P. vivax Erythrocyte Binding Protein region II (PvEBPII) and their associations with risk of clinical P. vivax malaria are not well understood. Methodology Total IgG and IgG subclasses 1, 2, and 3 that recognize four alleles of PvDBPII (AH, O, P, and Sal1), PvDBPIII-V and PvEBPII were measured in samples collected from a cohort of 1 to 3 year old Papua New Guinean (PNG) children living in a highly endemic area of PNG. The levels of binding inhibitory antibodies (BIAbs) to PvDBPII (AH, O, and Sal1) were also tested in a subset of children. The association of presence of IgG with age, cumulative exposure (measured as the product of age and malaria infections during follow-up) and prospective risk of clinical malaria were evaluated. Results The increase in antigen-specific total IgG, IgG1, and IgG3 with age and cumulative exposure was only observed for PvDBPII AH and PvEBPII. High levels of total IgG and predominant subclass IgG3 specific for PvDBPII AH were associated with decreased incidence of clinical P. vivax episodes (aIRR = 0.56–0.68, P≤0.001–0.021). High levels of total IgG and IgG1 to PvEBPII correlated strongly with protection against clinical vivax malaria compared with IgGs against all PvDBPII variants (aIRR = 0.38, P<0.001). Antibodies to PvDBPII AH and PvEBPII showed evidence of an additive effect, with a joint protective association of 70%. Conclusion Antibodies to the key parasite invasion ligands PvDBPII and PvEBPII are good correlates of protection against P. vivax malaria in PNG. This further strengthens the rationale for inclusion of PvDBPII in a recombinant subunit vaccine for P. vivax malaria and highlights the need for further functional studies to determine the potential of PvEBPII as a component of a subunit vaccine for P. vivax malaria. Plasmodium vivax is responsible for most malaria infections outside Africa, with 13.8 million vivax malaria cases reported annually worldwide. Antibodies are a key component of the host response to P. vivax infection, and their study can assist in identifying suitable vaccine candidates and serological biomarkers for malaria surveillance. The binding of P. vivax Duffy binding protein region II (PvDBPII) to the Duffy Antigen Receptor for Chemokines (DARC) is critical for P. vivax invasion of reticulocytes. Although the binding residues for DARC are highly conserved across PvDBPII, the parasite displays high sequence diversity in non-binding residues of PvDBPII. Other regions such as PvDBPIII-V are relatively conserved. Recently, sequencing of P. vivax field isolates, identified a homologous erythrocyte-binding protein (PvEBP), which harbors a domain, region II (PvEBPII), that is homologous to PvDBPII. To date, there has been limited investigation into the naturally acquired immunity to both PvDBPIII-V and PvEBPII in human populations. Using a longitudinal cohort study, we have characterized the serological response to PvDBPII, PvDBPIII-V, and PvEBPII among 1–3 years old PNG children and investigated associations with protection against clinical malaria. This study shows that both total IgG and IgG3 to the predominant PvDBPII AH allele in PNG, and total IgG and IgG1 to PvEBPII were associated with protection from P. vivax malaria.
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33
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Pires CV, Alves JRS, Lima BAS, Paula RB, Costa HL, Torres LM, Sousa TN, Soares IS, Sanchez BAM, Fontes CJF, Ntumngia FB, Adams JH, Kano FS, Carvalho LH. Blood-stage Plasmodium vivax antibody dynamics in a low transmission setting: A nine year follow-up study in the Amazon region. PLoS One 2018; 13:e0207244. [PMID: 30419071 PMCID: PMC6231651 DOI: 10.1371/journal.pone.0207244] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 10/26/2018] [Indexed: 11/23/2022] Open
Abstract
Plasmodium vivax remains a global health problem and its ability to cause relapses and subpatent infections challenge control and elimination strategies. Even in low malaria transmission settings, such as the Amazon basin, where progress in malaria control has caused a remarkable reduction in case incidence, a recent increase in P. vivax transmission demonstrates the continued vulnerability of P.vivax-exposed populations. As part of a search for complementary approaches to P.vivax surveillance in areas in which adults are the majority of the exposed-population, here we evaluated the potential of serological markers covering a wide range of immunogenicity to estimate malaria transmission trends. For this, antibodies against leading P. vivax blood-stage vaccine candidates were assessed during a 9 year follow-up study among adults exposed to unstable malaria transmission in the Amazon rainforest. Circulating antibody levels against immunogenic P. vivax proteins, such as the Apical Membrane Antigen-1, were a sensitive measure of recent P. vivax exposure, while antibodies against less immunogenic proteins were indicative of naturally-acquired immunity, including the novel engineered Duffy binding protein II immunogen (DEKnull-2). Our results suggest that the robustness of serology to estimate trends in P.vivax malaria transmission will depend on the immunological background of the study population, and that for adult populations exposed to unstable P.vivax malaria transmission, the local heterogeneity of antibody responses should be considered when considering use of serological surveillance.
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Affiliation(s)
- Camilla V. Pires
- Instituto René Rachou/FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | | | | | - Ruth B. Paula
- Instituto René Rachou/FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Helena L. Costa
- Instituto René Rachou/FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | | | - Taís N. Sousa
- Instituto René Rachou/FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
| | - Irene S. Soares
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Bruno A. M. Sanchez
- Instituto de Ciências da Saúde, Universidade Federal de Mato Grosso, Campus Sinop, Sinop, Mato Grosso, Brazil
| | - Cor J. F. Fontes
- Hospital Júlio Muller, Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, Brazil
| | - Francis B. Ntumngia
- Center for Global Health and Infectious Diseases Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - John H. Adams
- Center for Global Health and Infectious Diseases Research, Department of Global Health, College of Public Health, University of South Florida, Tampa, Florida, United States of America
| | - Flora S. Kano
- Instituto René Rachou/FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
- * E-mail: (LHC); (FSK)
| | - Luzia H. Carvalho
- Instituto René Rachou/FIOCRUZ, Belo Horizonte, Minas Gerais, Brazil
- * E-mail: (LHC); (FSK)
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Kano FS, de Souza AM, de Menezes Torres L, Costa MA, Souza-Silva FA, Sanchez BAM, Fontes CJF, Soares IS, de Brito CFA, Carvalho LH, Sousa TN. Susceptibility to Plasmodium vivax malaria associated with DARC (Duffy antigen) polymorphisms is influenced by the time of exposure to malaria. Sci Rep 2018; 8:13851. [PMID: 30218021 PMCID: PMC6138695 DOI: 10.1038/s41598-018-32254-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/03/2018] [Indexed: 11/28/2022] Open
Abstract
Malaria has provided a major selective pressure and has modulated the genetic diversity of the human genome. The variants of the Duffy Antigen/Receptor for Chemokines (DARC) gene have probably been selected by malaria parasites, particularly the FY*O allele, which is fixed in sub-Saharan Africa and confers resistance to Plasmodium vivax infection. Here, we showed the influence of genomic ancestry on the distribution of DARC genotypes in a highly admixed Brazilian population and confirmed the decreased susceptibility of the FY*A/FY*O genotype to clinical P. vivax malaria. FY*B/FY*O individuals were associated with a greater risk of developing clinical malaria. A remarkable difference among DARC variants concerning the susceptibility to clinical malaria was more evident for individuals who were less exposed to malaria, as measured by the time of residence in the endemic area. Additionally, we found that DARC-negative and FY*A/FY*O individuals had a greater chance of acquiring high levels of antibodies against the 19-kDa C-terminal region of the P. vivax merozoite surface protein-1. Altogether, our results provide evidence that DARC polymorphisms modulate the susceptibility to clinical P. vivax malaria and influence the naturally-acquired humoral immune response to malaria blood antigens, which may interfere with the efficacy of a future vaccine against malaria.
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Affiliation(s)
- Flora Satiko Kano
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Aracele Maria de Souza
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Leticia de Menezes Torres
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Marcelo Azevedo Costa
- Departamento de Engenharia de Produção, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Flávia Alessandra Souza-Silva
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | | | | | - Irene Silva Soares
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Cristiana Ferreira Alves de Brito
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Luzia Helena Carvalho
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil
| | - Tais Nobrega Sousa
- Molecular Biology and Malaria Immunology Research Group, Instituto René Rachou, Fundação Oswaldo Cruz (FIOCRUZ), Belo Horizonte, Minas Gerais, Brazil.
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Changrob S, McHenry AM, Nyunt MH, Sattabongkot J, Han ET, Adams JH, Chootong P. Persistence of Long-lived Memory B Cells specific to Duffy Binding Protein in individuals exposed to Plasmodium vivax. Sci Rep 2018; 8:8347. [PMID: 29844379 PMCID: PMC5973932 DOI: 10.1038/s41598-018-26677-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 05/17/2018] [Indexed: 12/25/2022] Open
Abstract
The major challenge in designing a protective Duffy binding protein region II (DBPII)-based vaccine against blood-stage vivax malaria is the high number of polymorphisms in critical residues targeted by binding-inhibitory antibodies. Here, longevity of antibody and memory B cell response (MBCs) to DBL-TH variants, DBL-TH2, -TH4, -TH5, -TH6 and -TH9 were analyzed in P. vivax-exposed individuals living in a low malaria transmission area of southern Thailand. Antibody to DBL-TH variants were significantly detected during P. vivax infection and it was persisted for up to 9 months post-infection. However, DBL-TH-specific MBC responses were stably maintained longer than antibody response, at least 3 years post-infection in the absence of re-infection. Phenotyping of B cell subsets showed the expansion of activated and atypical MBCs during acute and recovery phase of infection. While the persistence of DBL-TH-specific MBCs was found in individuals who had activated and atypical MBC expansion, anti-DBL-TH antibody responses was rapidly declined in plasma. The data suggested that these two MBCs were triggered by P. vivax infection, its expansion and stability may have impact on antibody responses. Our results provided evidence for ability of DBPII variant antigens in induction of long-lasting MBCs among individuals who were living in low malaria endemicity.
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Affiliation(s)
- Siriruk Changrob
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand
| | - Amy M McHenry
- Department of Biological Sciences, Southwestern Adventist University, Keene, Texas, 76059, USA
| | - Myat Htut Nyunt
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea
| | - John H Adams
- Department of Global Health, University of South Florida, Tampa, Florida, 33612, USA
| | - Patchanee Chootong
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand.
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Min HMK, Changrob S, Soe PT, Han JH, Muh F, Lee SK, Chootong P, Han ET. Immunogenicity of the Plasmodium vivax merozoite surface protein 1 paralog in the induction of naturally acquired antibody and memory B cell responses. Malar J 2017; 16:354. [PMID: 28854974 PMCID: PMC5577667 DOI: 10.1186/s12936-017-2000-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Accepted: 08/23/2017] [Indexed: 11/17/2022] Open
Abstract
Background The Plasmodium vivax merozoite surface protein 1 paralog (PvMSP1P-19) is a glycosylphosphatidylinositol (GPI)-anchored blood-stage protein that is expressed on the merozoite surface. It is proposed as a blood-stage vaccine candidate against P. vivax because of its ability to induce immune responses upon natural P. vivax exposure and in immunized animals. This study aimed to demonstrate the presence of inhibitory antibodies and memory B cell responses to the PvMSP1P-19 antigen during acute P. vivax infection and after recovery from infection. Methods To evaluate the antibody responses to PvMSP1P-19 during and after recovery from P. vivax infection, heparinized blood was collected from P. vivax-infected patients and recovered subjects to detect the total IgG response. The seropositive samples were defined into high and low responders, according to their optical density (OD) values obtained from ELISA. High responders were the subjects who had OD values above the OD of antisera from non-exposed controls plus 4× standard deviations, whereas low responders were the subjects who had OD values less than OD of antisera from non-exposed controls plus 4× standard deviations. The plasma from high and low responders were taken for testing the inhibitory activity against PvMSP1P-19-erythrocyte binding by in vitro EBIA. The sustainability of PvMSP1P-19-specific memory B cell responses after recovery from infection was analysed by ELISPOT. Results The anti-PvMSP1P-19 antibody levels were significantly higher in acutely infected P. vivax patients compared to healthy controls (P < 0.0001). Monitoring of the anti-PvMSP1P-19 antibody titre showed that the antibody was maintained for up to 9 months after recovery. Almost all high-responder groups strongly inhibited PvMSP1P-19 binding to erythrocytes, whereas no inhibition was shown in most low-responder samples. Interestingly, the inhibitory activity of the antibodies in some individuals from high-responder samples were stable for at least 12 months. The longevity of the antibody response was associated with the presence of PvMSP1P-19-specific memory B cells at 9 months after recovery from infection. Conclusions The PvMSP1P-19 antigen has immunogenicity during the induction of the antibody response, in which both the levels and inhibitory activity are maintained after the patient recovered from P. vivax infection. The maintenance of the antibody response was associated with the response of PvMSP1P-19-specific memory B cells. Therefore, the PvMSP1P-19 antigen should also be considered as a reliable vaccine candidate to develop a blood-stage vaccine against P. vivax.
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Affiliation(s)
- Hay Man Kyaw Min
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand
| | - Siriruk Changrob
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand
| | - Phyu Thwe Soe
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand
| | - Jin Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea
| | - Fauzi Muh
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea
| | - Seong-Kyun Lee
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea
| | - Patchanee Chootong
- Department of Clinical Microbiology and Applied Technology, Faculty of Medical Technology, Mahidol University, Bangkok, 10700, Thailand.
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea.
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Natural immune response to Plasmodium vivax alpha-helical coiled coil protein motifs and its association with the risk of P. vivax malaria. PLoS One 2017. [PMID: 28651021 PMCID: PMC5484505 DOI: 10.1371/journal.pone.0179863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Protein α-helical coiled coil structures are known to induce antibodies able to block critical functions in different pathogens. In a previous study, a total of 50 proteins of Plasmodium vivax erythrocytic asexual stages containing α-helical coiled coil structural motifs were identified in silico, and the corresponding peptides were chemically synthesized. A total of 43 peptides were recognized by naturally acquired antibodies in plasma samples from both Papua New Guinea (PNG) and Colombian adult donors. In this study, the association between IgG antibodies to these peptides and clinical immunity was further explored by measuring total IgG antibody levels to 24 peptides in baseline samples from a longitudinal study of children aged 1–3 years (n = 164) followed for 16 months. Samples were reactive to all peptides tested. Eight peptides were recognized by >50% of individuals, whereas only one peptide had < 20% reactivity. Children infected at baseline were seropositive to 23/24 peptides. No significant association was observed between antibody titers and age or molecular force of infection, suggesting that antibody levels had already reached an equilibrium. There was a strong association between antibody levels to all peptides and protection against P. vivax clinical episodes during the 16 months follow-up. These results suggest that the selected coiled coil antigens might be good markers of both exposure and acquired immunity to P. vivax malaria, and further preclinical investigation should be performed to determine their potential as P. vivax vaccine antigens.
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Payne RO, Silk SE, Elias SC, Milne KH, Rawlinson TA, Llewellyn D, Shakri AR, Jin J, Labbé GM, Edwards NJ, Poulton ID, Roberts R, Farid R, Jørgensen T, Alanine DG, de Cassan SC, Higgins MK, Otto TD, McCarthy JS, de Jongh WA, Nicosia A, Moyle S, Hill AV, Berrie E, Chitnis CE, Lawrie AM, Draper SJ. Human vaccination against Plasmodium vivax Duffy-binding protein induces strain-transcending antibodies. JCI Insight 2017; 2:93683. [PMID: 28614791 PMCID: PMC5470884 DOI: 10.1172/jci.insight.93683] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 05/16/2017] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND. Plasmodium vivax is the most widespread human malaria geographically; however, no effective vaccine exists. Red blood cell invasion by the P. vivax merozoite depends on an interaction between the Duffy antigen receptor for chemokines (DARC) and region II of the parasite’s Duffy-binding protein (PvDBP_RII). Naturally acquired binding-inhibitory antibodies against this interaction associate with clinical immunity, but it is unknown whether these responses can be induced by human vaccination. METHODS. Safety and immunogenicity of replication-deficient chimpanzee adenovirus serotype 63 (ChAd63) and modified vaccinia virus Ankara (MVA) viral vectored vaccines targeting PvDBP_RII (Salvador I strain) were assessed in an open-label dose-escalation phase Ia study in 24 healthy UK adults. Vaccines were delivered by the intramuscular route in a ChAd63-MVA heterologous prime-boost regimen using an 8-week interval. RESULTS. Both vaccines were well tolerated and demonstrated a favorable safety profile in malaria-naive adults. PvDBP_RII–specific ex-vivo IFN-γ T cell, antibody-secreting cell, memory B cell, and serum IgG responses were observed after the MVA boost immunization. Vaccine-induced antibodies inhibited the binding of vaccine homologous and heterologous variants of recombinant PvDBP_RII to the DARC receptor, with median 50% binding-inhibition titers greater than 1:100. CONCLUSION. We have demonstrated for the first time to our knowledge that strain-transcending antibodies can be induced against the PvDBP_RII antigen by vaccination in humans. These vaccine candidates warrant further clinical evaluation of efficacy against the blood-stage P. vivax parasite. TRIAL REGISTRATION. Clinicaltrials.gov NCT01816113. FUNDING. Support was provided by the UK Medical Research Council, UK National Institute of Health Research Oxford Biomedical Research Centre, and the Wellcome Trust. A clinical trial of a candidate blood-stage Plasmodium vivax vaccine targeting the Duffy-binding protein demonstrates safety and immunogenicity in healthy adults and induces strain-transcending antibodies.
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Affiliation(s)
- Ruth O Payne
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Sarah E Silk
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Sean C Elias
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Kathryn H Milne
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - David Llewellyn
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - A Rushdi Shakri
- International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India
| | - Jing Jin
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | | | - Nick J Edwards
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Ian D Poulton
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Rachel Roberts
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Ryan Farid
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Thomas Jørgensen
- ExpreS2, ion Biotechnologies, SCION-DTU Science Park, Hørsholm, Denmark
| | | | | | - Matthew K Higgins
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Thomas D Otto
- Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - James S McCarthy
- QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Willem A de Jongh
- ExpreS2, ion Biotechnologies, SCION-DTU Science Park, Hørsholm, Denmark
| | - Alfredo Nicosia
- ReiThera SRL (formerly Okairòs SRL), Viale Città d'Europa, Rome, Italy.,CEINGE, Naples, Italy.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy
| | - Sarah Moyle
- Clinical Biomanufacturing Facility, University of Oxford, Oxford, United Kingdom
| | - Adrian Vs Hill
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Eleanor Berrie
- Clinical Biomanufacturing Facility, University of Oxford, Oxford, United Kingdom
| | - Chetan E Chitnis
- International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, India.,Institut Pasteur, Department of Parasites and Insect Vectors, Paris, France
| | - Alison M Lawrie
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Simon J Draper
- The Jenner Institute, University of Oxford, Oxford, United Kingdom
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Requena P, Arévalo-Herrera M, Menegon M, Martínez-Espinosa FE, Padilla N, Bôtto-Menezes C, Malheiro A, Hans D, Castellanos ME, Robinson L, Samol P, Kochar S, Kochar SK, Kochar DK, Desai M, Sanz S, Quintó L, Mayor A, Rogerson S, Mueller I, Severini C, Del Portillo HA, Bardají A, Chitnis CC, Menéndez C, Dobaño C. Naturally Acquired Binding-Inhibitory Antibodies to Plasmodium vivax Duffy Binding Protein in Pregnant Women Are Associated with Higher Birth Weight in a Multicenter Study. Front Immunol 2017; 8:163. [PMID: 28261219 PMCID: PMC5313505 DOI: 10.3389/fimmu.2017.00163] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 01/31/2017] [Indexed: 12/11/2022] Open
Abstract
A vaccine to eliminate malaria would need a multi-stage and multi-species composition to achieve robust protection, but the lack of knowledge about antigen targets and mechanisms of protection precludes the development of fully efficacious malaria vaccines, especially for Plasmodium vivax (Pv). Pregnant women constitute a risk population who would greatly benefit from a vaccine preventing the adverse events of Plasmodium infection during gestation. We hypothesized that functional immune responses against putative targets of naturally acquired immunity to malaria and vaccine candidates will be associated with protection against malaria infection and/or poor outcomes during pregnancy. We measured (i) IgG responses to a large panel of Pv and Plasmodium falciparum (Pf) antigens, (ii) the capacity of anti-Pv ligand Duffy binding protein (PvDBP) antibodies to inhibit binding to Duffy antigen, and (iii) cellular immune responses to two Pv antigens, in a subset of 1,056 pregnant women from Brazil, Colombia, Guatemala, India, and Papua New Guinea (PNG). There were significant intraspecies and interspecies correlations for most antibody responses (e.g., PfMSP119 versus PfAMA1, Spearman’s rho = 0.81). Women from PNG and Colombia had the highest levels of IgG overall. Submicroscopic infections seemed sufficient to boost antibody responses in Guatemala but not antigen-specific cellular responses in PNG. Brazil had the highest percentage of Duffy binding inhibition (p-values versus Colombia: 0.040; Guatemala: 0.047; India: 0.003, and PNG: 0.153) despite having low anti-PvDBP IgG levels. Almost all antibodies had a positive association with present infection, and coinfection with the other species increased this association. Anti-PvDBP, anti-PfMSP1, and anti-PfAMA1 IgG levels at recruitment were positively associated with infection at delivery (p-values: 0.010, 0.003, and 0.023, respectively), suggesting that they are markers of malaria exposure. Peripheral blood mononuclear cells from Pv-infected women presented fewer CD8+IFN-γ+ T cells and secreted more G-CSF and IL-4 independently of the stimulus used in vitro. Functional anti-PvDBP levels at recruitment had a positive association with birth weight (difference per doubling antibody levels: 45 g, p-value: 0.046). Thus, naturally acquired binding-inhibitory antibodies to PvDBP might confer protection against poor outcomes of Pv malaria in pregnancy.
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Affiliation(s)
- Pilar Requena
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | | | | | - Flor E Martínez-Espinosa
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Amazonas, Brazil; Instituto Leônidas e Maria Deane (ILMD/Fiocruz Amazonia), Amazonia, Brazil
| | - Norma Padilla
- Centro de Estudios en Salud, Universidad del Valle de Guatemala , Guatemala City , Guatemala
| | - Camila Bôtto-Menezes
- Instituto Leônidas e Maria Deane (ILMD/Fiocruz Amazonia), Amazonia, Brazil; Universidade do Estado do Amazonas, Manaus, Amazonas, Brazil
| | - Adriana Malheiro
- Instituto de Ciências Biológicas, Universidade Federal do Amazonas , Manaus , Brazil
| | - Dhiraj Hans
- International Center for Genetic Engineering and Biotechnology , Delhi , India
| | | | - Leanne Robinson
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea; Macfarlane Burnet Institute of Medical Research, Melbourne, VIC, Australia; Walter and Eliza Hall Institute, Parkville, VIC, Australia
| | - Paula Samol
- Papua New Guinea Institute of Medical Research , Madang , Papua New Guinea
| | - Swati Kochar
- Medical College Bikaner , Bikaner, Rajasthan , India
| | | | | | - Meghna Desai
- Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Malaria Branch , Atlanta, GA , USA
| | - Sergi Sanz
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | - Llorenç Quintó
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | - Alfredo Mayor
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | | | - Ivo Mueller
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Catalonia, Spain; Walter and Eliza Hall Institute, Parkville, VIC, Australia
| | | | - Hernando A Del Portillo
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona, Barcelona, Catalonia, Spain; ICREA, Barcelona, Spain
| | - Azucena Bardají
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | - Chetan C Chitnis
- International Center for Genetic Engineering and Biotechnology , Delhi , India
| | - Clara Menéndez
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
| | - Carlota Dobaño
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic - Universitat de Barcelona , Barcelona, Catalonia , Spain
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