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Reyes RA, Turner L, Ssewanyana I, Jagannathan P, Feeney ME, Lavstsen T, Greenhouse B, Bol S, Bunnik EM. Differences in phenotype between long-lived memory B cells against Plasmodium falciparum merozoite antigens and variant surface antigens. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.01.596978. [PMID: 38895251 PMCID: PMC11185507 DOI: 10.1101/2024.06.01.596978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Plasmodium falciparum infections elicit strong humoral immune responses to two main groups of antigens expressed by blood-stage parasites: merozoite antigens that are involved in the erythrocyte invasion process and variant surface antigens that mediate endothelial sequestration of infected erythrocytes. Long-lived B cells against both antigen classes can be detected in the circulation for years after exposure, but have not been directly compared. Here, we studied the phenotype of long-lived memory and atypical B cells to merozoite antigens (MSP1 and AMA1) and variant surface antigens (the CIDRα1 domain of PfEMP1) in Ugandan adults before and after local reduction of P. falciparum transmission. After a median of 1.7 years without P. falciparum infections, the percentage of antigen-specific activated B cells declined, but long-lived antigen-specific B cells were still detectable in all individuals. The majority of MSP1/AMA1-specific B cells were CD95+CD11c+ memory B cells, which are primed for rapid differentiation into antibody-secreting cells, and FcRL5-T-bet- atypical B cells. On the other hand, most CIDRα1-specific B cells were CD95-CD11c- memory B cells. CIDRα1-specific B cells were also enriched among a subset of atypical B cells that seem poised for antigen presentation. These results point to differences in how these antigens are recognized or processed by the immune system and how P. falciparum-specific B cells will respond upon re-infection.
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Affiliation(s)
- Raphael A Reyes
- Department of Microbiology, Immunology & Molecular Genetics, Long School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Louise Turner
- Centre for translational Medicine & Parasitology, Department of Immunology and Microbiology, University of Copenhagen, and Department of Infectious Diseases, Righospitalet, Copenhagen, Denmark
| | | | - Prasanna Jagannathan
- Department of Medicine, Division of Infectious Diseases, Stanford University, Stanford, CA, USA
- Department of Microbiology & Immunology, Stanford University, Stanford, CA, USA
| | - Margaret E. Feeney
- Department of Pediatrics, University of California San Francisco, San Francisco, CA, USA
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Thomas Lavstsen
- Centre for translational Medicine & Parasitology, Department of Immunology and Microbiology, University of Copenhagen, and Department of Infectious Diseases, Righospitalet, Copenhagen, Denmark
| | - Bryan Greenhouse
- Department of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Sebastiaan Bol
- Department of Microbiology, Immunology & Molecular Genetics, Long School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Evelien M Bunnik
- Department of Microbiology, Immunology & Molecular Genetics, Long School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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2
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Doritchamou J, Nielsen MA, Chêne A, Viebig NK, Lambert LE, Sander AF, Semblat JP, Hundt S, Orr-Gonzalez S, Janitzek CM, Spiegel AJ, Clemmensen SB, Thomas ML, Nason MC, Snow-Smith M, Barnafo EK, Shiloach J, Chen BB, Nadakal S, Highsmith K, Ouahes T, Conteh S, Sharma A, Torano H, Butler B, Reiter K, Rausch KM, Scaria PV, Anderson C, Narum DL, Salanti A, Fried M, Theander TG, Gamain B, Duffy PE. Aotus nancymaae model predicts human immune response to the placental malaria vaccine candidate VAR2CSA. Lab Anim (NY) 2023; 52:315-323. [PMID: 37932470 PMCID: PMC10689237 DOI: 10.1038/s41684-023-01274-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 09/27/2023] [Indexed: 11/08/2023]
Abstract
Placental malaria vaccines (PMVs) are being developed to prevent severe sequelae of placental malaria (PM) in pregnant women and their offspring. The leading candidate vaccine antigen VAR2CSA mediates parasite binding to placental receptor chondroitin sulfate A (CSA). Despite promising results in small animal studies, recent human trials of the first two PMV candidates (PAMVAC and PRIMVAC) generated limited cross-reactivity and cross-inhibitory activity to heterologous parasites. Here we immunized Aotus nancymaae monkeys with three PMV candidates (PAMVAC, PRIMVAC and ID1-ID2a_M1010) adjuvanted with Alhydrogel, and exploited the model to investigate boosting of functional vaccine responses during PM episodes as well as with nanoparticle antigens. PMV candidates induced high levels of antigen-specific IgG with significant cross-reactivity across PMV antigens by enzyme-linked immunosorbent assay. Conversely, PMV antibodies recognized native VAR2CSA and blocked CSA adhesion of only homologous parasites and not of heterologous parasites. PM episodes did not significantly boost VAR2CSA antibody levels or serum functional activity; nanoparticle and monomer antigens alike boosted serum reactivity but not functional activities. Overall, PMV candidates induced functional antibodies with limited heterologous activity in Aotus monkeys, similar to responses reported in humans. The Aotus model appears suitable for preclinical downselection of PMV candidates and assessment of antibody boosting by PM episodes.
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Affiliation(s)
- Justin Doritchamou
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Morten A Nielsen
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Arnaud Chêne
- Université Paris Cité and Université des Antilles, INSERM, BIGR, Paris, France
| | - Nicola K Viebig
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Heidelberg, Germany
| | - Lynn E Lambert
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Adam F Sander
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | | | - Sophia Hundt
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Heidelberg, Germany
| | - Sachy Orr-Gonzalez
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Christoph Mikkel Janitzek
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Alicia J Spiegel
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | | | - Marvin L Thomas
- Division of Veterinary Resources, Office of Research Services, National Institutes of Health, Bethesda, MD, USA
| | - Martha C Nason
- Biostatistics Research Branch, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Maryonne Snow-Smith
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Emma K Barnafo
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Joseph Shiloach
- Biotechnology Unit, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, MD, USA
| | - Beth B Chen
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Steven Nadakal
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kendrick Highsmith
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tarik Ouahes
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Solomon Conteh
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ankur Sharma
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Holly Torano
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Brandi Butler
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Karine Reiter
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Kelly M Rausch
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Puthupparampil V Scaria
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Charles Anderson
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Ali Salanti
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Thor G Theander
- Centre for Medical Parasitology at the Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
| | - Benoit Gamain
- Université Paris Cité and Université des Antilles, INSERM, BIGR, Paris, France
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
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Raghavan SSR, Dagil R, Lopez-Perez M, Conrad J, Bassi MR, Quintana MDP, Choudhary S, Gustavsson T, Wang Y, Gourdon P, Ofori MF, Christensen SB, Minja DTR, Schmiegelow C, Nielsen MA, Barfod L, Hviid L, Salanti A, Lavstsen T, Wang K. Cryo-EM reveals the conformational epitope of human monoclonal antibody PAM1.4 broadly reacting with polymorphic malarial protein VAR2CSA. PLoS Pathog 2022; 18:e1010924. [PMCID: PMC9668162 DOI: 10.1371/journal.ppat.1010924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/10/2022] [Indexed: 11/17/2022] Open
Abstract
Malaria during pregnancy is a major global health problem caused by infection with Plasmodium falciparum parasites. Severe effects arise from the accumulation of infected erythrocytes in the placenta. Here, erythrocytes infected by late blood-stage parasites adhere to placental chondroitin sulphate A (CS) via VAR2CSA-type P. falciparum erythrocyte membrane protein 1 (PfEMP1) adhesion proteins. Immunity to placental malaria is acquired through exposure and mediated through antibodies to VAR2CSA. Through evolution, the VAR2CSA proteins have diversified in sequence to escape immune recognition but retained their overall macromolecular structure to maintain CS binding affinity. This structural conservation may also have allowed development of broadly reactive antibodies to VAR2CSA in immune women. Here we show the negative stain and cryo-EM structure of the only known broadly reactive human monoclonal antibody, PAM1.4, in complex with VAR2CSA. The data shows how PAM1.4’s broad VAR2CSA reactivity is achieved through interactions with multiple conserved residues of different sub-domains forming conformational epitope distant from the CS binding site on the VAR2CSA core structure. Thus, while PAM1.4 may represent a class of antibodies mediating placental malaria immunity by inducing phagocytosis or NK cell-mediated cytotoxicity, it is likely that broadly CS binding-inhibitory antibodies target other epitopes at the CS binding site. Insights on both types of broadly reactive monoclonal antibodies may aid the development of a vaccine against placental malaria.
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Affiliation(s)
- Sai Sundar Rajan Raghavan
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Robert Dagil
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Mary Lopez-Perez
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Julian Conrad
- Swedish National Cryo-EM Facility, Science for Life Laboratories, Solna, Sweden
| | - Maria Rosaria Bassi
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Maria del Pilar Quintana
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Swati Choudhary
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Tobias Gustavsson
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Yong Wang
- Joint Research Centre for Engineering Biology, Zhejiang University-University of Edinburgh Institute, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Pontus Gourdon
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Michael Fokuo Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Sebastian Boje Christensen
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | | | - Christentze Schmiegelow
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Morten Agertoug Nielsen
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Lea Barfod
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Lars Hviid
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Ali Salanti
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Thomas Lavstsen
- Centre for Medical Parasitology at Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, and Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
- * E-mail: (TL); (KW)
| | - Kaituo Wang
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail: (TL); (KW)
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4
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Lopez-Perez M, Viwami F, Seidu Z, Jensen ATR, Doritchamou J, Ndam NT, Hviid L. PfEMP1-Specific Immunoglobulin G Reactivity Among Beninese Pregnant Women With Sickle Cell Trait. Open Forum Infect Dis 2021; 8:ofab527. [PMID: 34909438 PMCID: PMC8664683 DOI: 10.1093/ofid/ofab527] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/14/2021] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Sickle cell trait (HbAS) protects against severe Plasmodium falciparum malaria but not against placental malaria (PM). In this study, P falciparum erythrocyte membrane protein (PfEMP1)-specific antibodies were measured in HbAA and HbAS Beninese pregnant women as a proxy of exposure to specific PfEMP1 variants. METHODS Plasma samples collected at delivery from 338 HbAA and 63 HbAS women were used to measure immunoglobulin (Ig)G levels to 6 recombinant PfEMP1 proteins and 3 corresponding native proteins expressed on the infected erythrocyte (IE) surface. Immunoglobulin G-mediated inhibition of VAR2CSA+ IEs adhesion to chondroitin sulfate A (CSA) was also tested. RESULTS Levels of PfEMP1-specific IgG were similar in the 2 groups, except for native IT4VAR09 on IEs, where IgG levels were significantly higher in HbAS women. Adjusted odds ratios for women with positive IgG to HB3VAR06 and PFD1235w suggest a lower risk of infection with these virulent variants among HbAS individuals. The percentage of IEs binding to CSA did not differ between HbAA and HbAS women, but it correlated positively with levels of anti-VAR2CSA and parity. Women with PM had lower levels of anti-VAR2CSA-specific IgG and lower IgG-mediated inhibition of IE adhesion to CSA. CONCLUSIONS The findings support similar malaria exposure in HbAA and HbAS women and a lack of HbAS-dependent protection against placental infection among pregnant women.
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Affiliation(s)
- Mary Lopez-Perez
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Firmine Viwami
- UMR 261 MERIT, Université de Paris, Institut de Recherche pour le Développement, Paris, France
- Institut de Recherche Clinique du Benin, Abomey Calavi, Benin
| | - Zakaria Seidu
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
- West Africa Centre for Cell Biology of Infectious Pathogens (WACCBIP), Department of Biochemistry, Cell and Molecular Biology, University of Ghana, Accra, Ghana
| | - Anja T R Jensen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Nicaise Tuikue Ndam
- UMR 261 MERIT, Université de Paris, Institut de Recherche pour le Développement, Paris, France
- Institut de Recherche Clinique du Benin, Abomey Calavi, Benin
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Centre for Medical Parasitology, Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
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5
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Afucosylated Plasmodium falciparum-specific IgG is induced by infection but not by subunit vaccination. Nat Commun 2021; 12:5838. [PMID: 34611164 PMCID: PMC8492741 DOI: 10.1038/s41467-021-26118-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 09/11/2021] [Indexed: 01/02/2023] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family members mediate receptor- and tissue-specific sequestration of infected erythrocytes (IEs) in malaria. Antibody responses are a central component of naturally acquired malaria immunity. PfEMP1-specific IgG likely protects by inhibiting IE sequestration and through IgG-Fc Receptor (FcγR) mediated phagocytosis and killing of antibody-opsonized IEs. The affinity of afucosylated IgG to FcγRIIIa is up to 40-fold higher than fucosylated IgG, resulting in enhanced antibody-dependent cellular cytotoxicity. Most IgG in plasma is fully fucosylated, but afucosylated IgG is elicited in response to enveloped viruses and to paternal alloantigens during pregnancy. Here we show that naturally acquired PfEMP1-specific IgG is strongly afucosylated in a stable and exposure-dependent manner, and efficiently induces FcγRIIIa-dependent natural killer (NK) cell degranulation. In contrast, immunization with a subunit PfEMP1 (VAR2CSA) vaccine results in fully fucosylated specific IgG. These results have implications for understanding protective natural- and vaccine-induced immunity to malaria. Here, Larsen et al. describe differences in Fc fucosylation of P. falciparum PfEMP1-specific IgG produced in response to natural infection versus VAR2CSA-type subunit vaccination, which leads to differences in the ability to induce FcγRIIIa-dependent natural killer cell degranulation.
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Larsen MD, Lopez-Perez M, Dickson EK, Ampomah P, Tuikue Ndam N, Nouta J, Koeleman CAM, Ederveen ALH, Mordmüller B, Salanti A, Nielsen MA, Massougbodji A, van der Schoot CE, Ofori MF, Wuhrer M, Hviid L, Vidarsson G. Afucosylated Plasmodium falciparum-specific IgG is induced by infection but not by subunit vaccination. Nat Commun 2021. [PMID: 34611164 DOI: 10.1101/2021.04.23.441082v1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family members mediate receptor- and tissue-specific sequestration of infected erythrocytes (IEs) in malaria. Antibody responses are a central component of naturally acquired malaria immunity. PfEMP1-specific IgG likely protects by inhibiting IE sequestration and through IgG-Fc Receptor (FcγR) mediated phagocytosis and killing of antibody-opsonized IEs. The affinity of afucosylated IgG to FcγRIIIa is up to 40-fold higher than fucosylated IgG, resulting in enhanced antibody-dependent cellular cytotoxicity. Most IgG in plasma is fully fucosylated, but afucosylated IgG is elicited in response to enveloped viruses and to paternal alloantigens during pregnancy. Here we show that naturally acquired PfEMP1-specific IgG is strongly afucosylated in a stable and exposure-dependent manner, and efficiently induces FcγRIIIa-dependent natural killer (NK) cell degranulation. In contrast, immunization with a subunit PfEMP1 (VAR2CSA) vaccine results in fully fucosylated specific IgG. These results have implications for understanding protective natural- and vaccine-induced immunity to malaria.
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Affiliation(s)
- Mads Delbo Larsen
- Department of Experimental Immunohematology, Sanquin Research, Amsterdam, The Netherlands.,Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Mary Lopez-Perez
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emmanuel Kakra Dickson
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Paulina Ampomah
- Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana
| | | | - Jan Nouta
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
| | - Carolien A M Koeleman
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Benjamin Mordmüller
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands.,Institut für Tropenmedizin, Universitätsklinikum Tübingen, Tübingen, Germany
| | - Ali Salanti
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Morten Agertoug Nielsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Achille Massougbodji
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance (CERPAGE), Faculté des Sciences de la Santé, Université d'Abomey-Calavi, Godomey, Benin
| | - C Ellen van der Schoot
- Department of Experimental Immunohematology, Sanquin Research, Amsterdam, The Netherlands.,Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Michael F Ofori
- Department of Immunology, Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Manfred Wuhrer
- Center for Proteomics and Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
| | - Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark. .,Centre for Medical Parasitology, Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark.
| | - Gestur Vidarsson
- Department of Experimental Immunohematology, Sanquin Research, Amsterdam, The Netherlands. .,Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands.
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7
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Soares RR, Nakaie CR, Rodrigues-da-Silva RN, da Silva RL, Lima-Junior JDC, Scopel KKG. Main B-cell epitopes of PvAMA-1 and PvMSP-9 are targeted by naturally acquired antibodies and epitope-specific memory cells in acute and convalescent phases of vivax malaria. Parasite Immunol 2020; 42:e12705. [PMID: 32096238 DOI: 10.1111/pim.12705] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 01/30/2020] [Accepted: 02/11/2020] [Indexed: 01/11/2023]
Abstract
Although antibodies are considered critical for malaria protection, little is known about the mechanisms/factors that maintain humoral immunity, especially regarding the induction and maintenance of memory B cells over time. In Brazilian endemic areas, this is the first time that the profile of antibody responses and the occurrence of antigen-specific memory B cells (MBC) against P vivax were investigated during acute malaria and up to six months after parasite clearance. For this, we selected two peptides, PvAMA-1(S290-K307) and PvMSP-9(E795-A808) , which represent the apical membrane antigen-1 and merozoite surface protein-9 of P vivax, respectively. Both peptides were previously described as containing linear B-cell epitopes. Our findings were as follows: 1-both peptides were recognized by IgG antibodies at a high frequency (between 24% and 81%) in all study groups; 2-in the absence of infection, the IgG levels remained stable throughout 6 months of follow-up; and 3-PvAMA-1(S290-K307) and PvMSP-9(E795-A808) -specific MBCs were detected in all individual groups in the absence of reinfection throughout the follow-up period, suggesting long-lived MBC. However, no positive association was observed between malaria-specific antibody levels and frequency of MBCs over time. Taken together, these results suggest that peptides can be, in the future, an alternative strategy to polypeptidic vaccine formulation.
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Affiliation(s)
- Roberta Reis Soares
- Department of Parasitology, Microbiology and Immunology, Institute of Biological Sciences, Federal University of Juiz de For a, Juiz de For a, Brazil
| | - Clovis Ryuichi Nakaie
- Departament of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | | | - Rogério Lauria da Silva
- Departament of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | | | - Kézia Katiani Gorza Scopel
- Department of Parasitology, Microbiology and Immunology, Institute of Biological Sciences, Federal University of Juiz de For a, Juiz de For a, Brazil
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8
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Abstract
A single exposure to many viral and bacterial pathogens typically induces life-long immunity, however, the development of the protective immunity to Plasmodium parasites is strikingly less efficient and achieves only partial protection, with adults residing in endemic areas often experiencing asymptomatic infections. Although naturally acquired immunity to malaria requires both cell-mediated and humoral immune responses, antibodies govern the control of malarial disease caused by the blood-stage form of the parasites. A large body of epidemiological evidence described that antibodies to Plasmodium antigens are inefficiently generated and rapidly lost without continued parasite exposure, suggesting that malaria is accompanied by defects in the development of immunological B cell memory. This topic has been of focus of recent studies of malaria infection in humans and mice. This review examines the main findings to date on the processes that modulate the acquisition of memory B cell responses to malaria, and highlights the importance of closing outstanding gaps of knowledge in the field for the rational design of next generation therapeutics against malaria.
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Affiliation(s)
- Ann Ly
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Diana S Hansen
- The Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
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9
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Larsen MD, Quintana MDP, Ditlev SB, Bayarri-Olmos R, Ofori MF, Hviid L, Garred P. Evasion of Classical Complement Pathway Activation on Plasmodium falciparum-Infected Erythrocytes Opsonized by PfEMP1-Specific IgG. Front Immunol 2019; 9:3088. [PMID: 30666256 PMCID: PMC6330326 DOI: 10.3389/fimmu.2018.03088] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/13/2018] [Indexed: 01/01/2023] Open
Abstract
Members of the PfEMP1 protein family are expressed on the surface of P. falciparum-infected erythrocytes (IEs), where they contribute to the pathogenesis of malaria and are important targets of acquired immunity. Although the PfEMP1-specific antibody response is dominated by the opsonizing and complement-fixing subclasses IgG1 and IgG3, activation of the classical complement pathway by antibody-opsonized IEs does not appear to be a major immune effector mechanism. To study the molecular background for this, we used ELISA and flow cytometry to assess activation of the classical component pathway by recombinant and native PfEMP1 antigen opsonized by polyclonal and monoclonal PfEMP1-specific human IgG. Polyclonal IgG specific for VAR2CSA-type PfEMP1 purified from a pool of human immune plasma efficiently activated the classical complement pathway when bound to recombinant PfEMP1 in ELISA. In contrast, no activation of complement could be detected by flow cytometry when the same IgG preparation was used to opsonize IEs expressing the corresponding native PfEMP1 antigen. After engineering of a VAR2CSA-specific monoclonal antibody to facilitate its on-target hexamerization, complement activation was detectable in an ELISA optimized for uniform orientation of the immobilized antigen. In contrast, the antibody remained unable to activate complement when bound to native VAR2CSA on IEs. Our data suggest that the display of PfEMP1 proteins on IEs is optimized to prevent activation of the classical complement pathway, and thus represents a hitherto unappreciated parasite strategy to evade acquired immunity to malaria.
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Affiliation(s)
- Mads Delbo Larsen
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark
| | - Maria Del Pilar Quintana
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sisse Bolm Ditlev
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Rafael Bayarri-Olmos
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark
| | - Michael Fokuo Ofori
- Department of Immunology, Noguchi Memorial Institute of Medical Research, University of Ghana, Accra, Ghana
| | - Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Centre for Medical Parasitology, Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| | - Peter Garred
- Laboratory of Molecular Medicine, Department of Clinical Immunology, Rigshospitalet, Copenhagen, Denmark
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10
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IgG Responses to the Plasmodium falciparum Antigen VAR2CSA in Colombia Are Restricted to Pregnancy and Are Not Induced by Exposure to Plasmodium vivax. Infect Immun 2018; 86:IAI.00136-18. [PMID: 29784859 PMCID: PMC6056870 DOI: 10.1128/iai.00136-18] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 05/11/2018] [Indexed: 12/20/2022] Open
Abstract
Clinical immunity to malaria is associated with the acquisition of IgG specific for members of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family of clonally variant antigens on the surface of infected erythrocytes (IEs). The VAR2CSA subtype of PfEMP1 mediates IE binding in the placenta. Clinical immunity to malaria is associated with the acquisition of IgG specific for members of the Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family of clonally variant antigens on the surface of infected erythrocytes (IEs). The VAR2CSA subtype of PfEMP1 mediates IE binding in the placenta. VAR2CSA-specific IgG is normally acquired only after exposure to placental parasites. However, it was recently reported that men and children from Colombia often have high levels of functional VAR2CSA-specific IgG. This potentially undermines the current understanding of malaria immunity in pregnant women, and we thus conducted a study to assess further the levels of VAR2CSA-specific IgG in pregnant and nonpregnant Colombians. Plasma IgG against two full-length recombinant PfEMP1 proteins (one of the VAR2CSA type and one not) produced in baculovirus-transfected insect cells was detected frequently among Colombian men, children, and pregnant women with acute or previous malaria exposure. In contrast, IgG reactivity to a homologous full-length VAR2CSA-type protein expressed in Chinese hamster ovary (CHO) cells was low and infrequent among the Colombian plasma samples, as was reactivity to both corresponding native PfEMP1 proteins. Moreover, human and rabbit antibodies specific for Plasmodium vivax Duffy-binding protein (PvDBP), a protein with some homology to PfEMP1, did not react with VAR2CSA-type recombinant or native proteins, although the mouse monoclonal and PvDBP-specific antibody 3D10 was weakly reactive with recombinant proteins expressed in baculovirus-transfected insect cells. Our data indicate that the previously reported Colombian IgG reactivity to recombinant VAR2CSA is not malaria specific and that the acquisition of VAR2CSA-specific IgG is restricted to pregnancy, in Colombia and elsewhere.
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11
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Kinetics of antibody responses to PfRH5-complex antigens in Ghanaian children with Plasmodium falciparum malaria. PLoS One 2018; 13:e0198371. [PMID: 29883485 PMCID: PMC5993283 DOI: 10.1371/journal.pone.0198371] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/17/2018] [Indexed: 11/21/2022] Open
Abstract
Plasmodium falciparum PfRH5 protein binds Ripr, CyRPA and Pf113 to form a complex that is essential for merozoite invasion of erythrocytes. The inter-genomic conservation of the PfRH5 complex proteins makes them attractive blood stage vaccine candidates. However, little is known about how antibodies to PfRH5, CyRPA and Pf113 are acquired and maintained in naturally exposed populations, and the role of PfRH5 complex proteins in naturally acquired immunity. To provide such data, we studied 206 Ghanaian children between the ages of 1–12 years, who were symptomatic, asymptomatic or aparasitemic and healthy. Plasma levels of antigen-specific IgG and IgG subclasses were measured by ELISA at several time points during acute disease and convalescence. On the day of admission with acute P. falciparum malaria, the prevalence of antibodies to PfRH5-complex proteins was low compared to other merozoite antigens (EBA175, GLURP-R0 and GLURP-R2). At convalescence, the levels of RH5-complex-specific IgG were reduced, with the decay of PfRH5-specific IgG being slower than the decay of IgG specific for CyRPA and Pf113. No correlation between IgG levels and protection against P. falciparum malaria was observed for any of the PfRH5 complex proteins. From this we conclude that specific IgG was induced against proteins from the PfRH5-complex during acute P. falciparum malaria, but the prevalence was low and the IgG levels decayed rapidly after treatment. These data indicate that the levels of IgG specific for PfRH5-complex proteins in natural infections in Ghanaian children were markers of recent exposure only.
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12
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Fried M, Kurtis JD, Swihart B, Morrison R, Pond-Tor S, Barry A, Sidibe Y, Keita S, Mahamar A, Andemel N, Attaher O, Dembele AB, Cisse KB, Diarra BS, Kanoute MB, Narum DL, Dicko A, Duffy PE. Antibody levels to recombinant VAR2CSA domains vary with Plasmodium falciparum parasitaemia, gestational age, and gravidity, but do not predict pregnancy outcomes. Malar J 2018. [PMID: 29523137 PMCID: PMC5845157 DOI: 10.1186/s12936-018-2258-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Background Maternal malaria is a tropical scourge associated with poor pregnancy outcomes. Women become resistant to Plasmodium falciparum pregnancy malaria as they acquire antibodies to the variant surface antigen VAR2CSA, a leading vaccine candidate. Because malaria infection may increase VAR2CSA antibody levels and thereby confound analyses of immune protection, gravidity-dependent changes in antibody levels during and after infection, and the effect of VAR2CSA antibodies on pregnancy outcomes were evaluated. Methods Pregnant women enrolled in a longitudinal cohort study of mother-infant pairs in Ouelessebougou, Mali provided plasma samples at enrollment, gestational week 30–32, and delivery. Antibody levels to VAR2CSA domains were measured using a multiplex bead-based assay. Results Antibody levels to VAR2CSA were higher in multigravidae than primigravidae. Malaria infection was associated with increased antibody levels to VAR2CSA domains. In primigravidae but not in secundigravidae or multigravidae, antibodies levels sharply declined after an infection. A relationship between any VAR2CSA antibody specificity and protection from adverse pregnancy outcomes was not detected. Conclusions During malaria infection, primigravidae acquire short-lived antibodies. The lack of an association between VAR2CSA domain antibody reactivity and improved pregnancy outcomes suggests that the recombinant proteins may not present native epitopes targeted by protective antibodies. Electronic supplementary material The online version of this article (10.1186/s12936-018-2258-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, USA.
| | - Jonathan D Kurtis
- Center for International Health Research, Rhode Island Hospital, Brown University Medical School, Providence, RI, USA
| | - Bruce Swihart
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, USA
| | - Robert Morrison
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, USA
| | - Sunthorn Pond-Tor
- Center for International Health Research, Rhode Island Hospital, Brown University Medical School, Providence, RI, USA
| | - Amadou Barry
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Youssoufa Sidibe
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Sekouba Keita
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Almahamoudou Mahamar
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Naissem Andemel
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, USA
| | - Oumar Attaher
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Adama B Dembele
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Kadidia B Cisse
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Bacary S Diarra
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Moussa B Kanoute
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, USA
| | - Alassane Dicko
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, USA
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13
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Ubillos I, Campo JJ, Requena P, Ome-Kaius M, Hanieh S, Rose H, Samol P, Barrios D, Jiménez A, Bardají A, Mueller I, Menéndez C, Rogerson S, Moncunill G, Dobaño C. Chronic Exposure to Malaria Is Associated with Inhibitory and Activation Markers on Atypical Memory B Cells and Marginal Zone-Like B Cells. Front Immunol 2017; 8:966. [PMID: 28878766 PMCID: PMC5573441 DOI: 10.3389/fimmu.2017.00966] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 07/28/2017] [Indexed: 11/24/2022] Open
Abstract
In persistent infections that are accompanied by chronic immune activation, such as human immunodeficiency virus, hepatitis C virus, and malaria, there is an increased frequency of a phenotypically distinct subset of memory B cells lacking the classic memory marker CD27 and showing a reduced capacity to produce antibodies. However, critical knowledge gaps remain on specific B cell changes and immune adaptation in chronic infections. We hypothesized that expansion of atypical memory B cells (aMBCs) and reduction of activated peripheral marginal zone (MZ)-like B cells in constantly exposed individuals might be accompanied by phenotypic changes that would confer a tolerogenic profile, helping to establish tolerance to infections. To better understand malaria-associated phenotypic abnormalities on B cells, we analyzed peripheral blood mononuclear cells from 55 pregnant women living in a malaria-endemic area of Papua Nueva Guinea and 9 Spanish malaria-naïve individuals using four 11-color flow cytometry panels. We assessed the expression of markers of B cell specificity (IgG and IgM), activation (CD40, CD80, CD86, b220, TACI, and CD150), inhibition (PD1, CD95, and CD71), and migration (CCR3, CXCR3, and CD62l). We found higher frequencies of active and resting aMBC and marked reduction of MZ-like B cells, although changes in absolute cell counts could not be assessed. Highly exposed women had higher PD1+-, CD95+-, CD40+-, CD71+-, and CD80+-activated aMBC frequencies than non-exposed subjects. Malaria exposure increased frequencies of b220 and proapoptotic markers PD1 and CD95, and decreased expression of the activation marker TACI on MZ-like B cells. The increased frequencies of inhibitory and apoptotic markers on activated aMBCs and MZ-like B cells in malaria-exposed adults suggest an immune-homeostatic mechanism for maintaining B cell development and function while simultaneously downregulating hyperreactive B cells. This mechanism would keep the B cell activation threshold high enough to control infection but impaired enough to tolerate it, preventing systemic inflammation.
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Affiliation(s)
- Itziar Ubillos
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Joseph J. Campo
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
- Antigen Discovery Inc., Irvine, CA, United States
| | - Pilar Requena
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
- Facultad de Medicina, Universidad de Granada, Granada, Spain
| | - Maria Ome-Kaius
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Sarah Hanieh
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Honor Rose
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Paula Samol
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Diana Barrios
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Alfons Jiménez
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
- CIBER Epidemiology and Public Health (CIBERESP), Barcelona, Spain
| | - Azucena Bardají
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Ivo Mueller
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Clara Menéndez
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | | | - Gemma Moncunill
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Carlota Dobaño
- ISGlobal, Barcelona Ctr. Int. Health Res. (CRESIB), Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
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14
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McLean ARD, Boel ME, McGready R, Ataide R, Drew D, Tsuboi T, Beeson JG, Nosten F, Simpson JA, Fowkes FJI. Antibody responses to Plasmodium falciparum and Plasmodium vivax blood-stage and sporozoite antigens in the postpartum period. Sci Rep 2016; 6:32159. [PMID: 27558000 PMCID: PMC4997260 DOI: 10.1038/srep32159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/03/2016] [Indexed: 11/17/2022] Open
Abstract
During pregnancy a variety of immunological changes occur to accommodate the fetus. It is unknown whether these changes continue to affect humoral immunity postpartum or how quickly they resolve. IgG levels were measured to P. falciparum and P. vivax antigens in 201 postpartum and 201 controls over 12 weeks. Linear mixed-effects models assessed antibody maintenance over time and the effect of microscopically confirmed Plasmodium spp. infection on antibody levels, and whether this was different in postpartum women compared with control women. Postpartum women had reduced Plasmodium spp. antibody levels compared to controls at baseline. Over 12 weeks, mean antibody levels in postpartum women increased to levels observed in control women. Microscopically confirmed P. falciparum and P. vivax infections during follow-up were associated with an increase in species-specific antibodies with similar magnitudes of boosting observed in postpartum and control women. Antibodies specific for pregnancy-associated, VAR2CSA-expressing parasites did not rapidly decline postpartum and did not boost in response to infection in either postpartum or control women. After pregnancy, levels of malaria-specific antibodies were reduced, but recovered to levels seen in control women. There was no evidence of an impaired ability to mount a boosting response in postpartum women.
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Affiliation(s)
- Alistair R D McLean
- Macfarlane Burnet Institute of Medical Research, Melbourne 3004, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne 3004, Australia
| | - Machteld E Boel
- Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot 63110, Thailand
| | - Rose McGready
- Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot 63110, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX1 2JD, UK
| | - Ricardo Ataide
- Macfarlane Burnet Institute of Medical Research, Melbourne 3004, Australia
| | - Damien Drew
- Macfarlane Burnet Institute of Medical Research, Melbourne 3004, Australia
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyuma 790-8577, Japan
| | - James G Beeson
- Macfarlane Burnet Institute of Medical Research, Melbourne 3004, Australia.,Department of Microbiology, Monash University 3800, Australia
| | - François Nosten
- Shoklo Malaria Research Unit (SMRU), Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Mae Sot 63110, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX1 2JD, UK
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne 3004, Australia
| | - Freya J I Fowkes
- Macfarlane Burnet Institute of Medical Research, Melbourne 3004, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne 3004, Australia.,Department of Epidemiology and Preventative Medicine, Monash University 3800, Victoria, Australia
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15
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Abstract
Malaria is one of the most serious infectious diseases with ~250 million clinical cases annually. Most cases of severe disease are caused by Plasmodium falciparum. The blood stage of Plasmodium parasite is entirely responsible for malaria-associated pathology. Disease syndromes range from fever to more severe complications, including respiratory distress, metabolic acidosis, renal failure, pulmonary oedema and cerebral malaria. The most susceptible population to severe malaria is children under the age of 5, with low levels of immunity. It is only after many years of repeated exposure, that individuals living in endemic areas develop clinical immunity. This form of protection does not result in sterilizing immunity but prevents clinical episodes by substantially reducing parasite burden. Naturally acquired immunity predominantly targets blood-stage parasites and it is known to require antibody responses. A large body of epidemiological evidence suggests that antibodies to Plasmodium antigens are inefficiently generated and rapidly lost in the absence of ongoing exposure, which suggests a defect in the development of B cell immunological memory. This review summarizes the main findings to date contributing to our understanding on cellular processes underlying the slow acquisition of humoral immunity to malaria. Some of the key outstanding questions in the field are discussed.
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16
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Abstract
With increasing malaria control and goals of malaria elimination, many endemic areas are transitioning from high-to-low-to-no malaria transmission. Reductions in transmission will impact on the development of naturally acquired immunity to malaria, which develops after repeated exposure to Plasmodium spp. However, it is currently unclear how declining transmission and malaria exposure will affect the development and maintenance of naturally acquired immunity. Here we review the key processes which underpin this knowledge; the amount of Plasmodium spp. exposure required to generate effective immune responses, the longevity of antibody responses and the ability to mount an effective response upon re-exposure through memory responses. Lastly we identify research priorities which will increase our understanding of how changing transmission will impact on malarial immunity.
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17
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Abstract
Members of the clonally variant Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) family mediate adhesion of infected erythrocytes (IEs) to vascular receptors. PfEMP1 expression is normally confined to nanoscale knob protrusions on the IE surface membrane. To investigate the relationship between the densities of these IE surface knobs and the PfEMP1 variant expressed, we used specific antibody panning to generate three sublines of the P. falciparum clone IT4, which expresses the PfEMP1 variants IT4VAR04, IT4VAR32b, and IT4VAR60. The knob density in each subline was then determined by atomic force microscopy (AFM) and scanning electron microscopy (SEM) and compared to PfEMP1 and knob-associated histidine-rich protein (KAHRP) expression. Selection for uniform expression of IT4VAR04 produced little change in knob density, compared to unselected IEs. In contrast, selection for IT4VAR32b expression increased knob density approximately 3-fold, whereas IEs selected for IT4VAR60 expression were essentially knobless. When IT4VAR60+ IEs were subsequently selected to express IT4VAR04 or IT4VAR32b, they again displayed low and high knob densities, respectively. All sublines expressed KAHRP regardless of the PfEMP1 expressed. Our study documents for the first time that knob density is related to the PfEMP1 variant expressed. This may reflect topological requirements to ensure optimal adhesive properties of the IEs. Infections with Plasmodium falciparum malaria parasites are still responsible for many deaths, especially among children and pregnant women. New interventions are needed to reduce severe illness and deaths caused by this malaria parasite. Thus, a better understanding of the mechanisms behind the pathogenesis is essential. A main reason why Plasmodium falciparum malaria is more severe than disease caused by other malaria species is its ability to express variant antigens on the infected erythrocyte surface. These antigens are presented on membrane protrusions known as knobs. This study set out to investigate the interplay between different variant antigens on the surface of P. falciparum-infected erythrocytes and the density of the knobs on which the antigens are expressed. Such a direct analysis of this relationship has not been reported before but adds to the important understanding of the complexity of malaria antigen presentation.
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18
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Stevenson L, Laursen E, Cowan GJ, Bandoh B, Barfod L, Cavanagh DR, Andersen GR, Hviid L. α2-Macroglobulin Can Crosslink Multiple Plasmodium falciparum Erythrocyte Membrane Protein 1 (PfEMP1) Molecules and May Facilitate Adhesion of Parasitized Erythrocytes. PLoS Pathog 2015; 11:e1005022. [PMID: 26134405 PMCID: PMC4489720 DOI: 10.1371/journal.ppat.1005022] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 06/12/2015] [Indexed: 11/19/2022] Open
Abstract
Rosetting, the adhesion of Plasmodium falciparum-infected erythrocytes to uninfected erythrocytes, involves clonal variants of the parasite protein P. falciparum erythrocyte membrane protein 1 (PfEMP1) and soluble serum factors. While rosetting is a well-known phenotypic marker of parasites associated with severe malaria, the reason for this association remains unclear, as do the molecular details of the interaction between the infected erythrocyte (IE) and the adhering erythrocytes. Here, we identify for the first time a single serum factor, the abundant serum protease inhibitor α2-macroglobulin (α2M), which is both required and sufficient for rosetting mediated by the PfEMP1 protein HB3VAR06 and some other rosette-mediating PfEMP1 proteins. We map the α2M binding site to the C terminal end of HB3VAR06, and demonstrate that α2M can bind at least four HB3VAR06 proteins, plausibly augmenting their combined avidity for host receptors. IgM has previously been identified as a rosette-facilitating soluble factor that acts in a similar way, but it cannot induce rosetting on its own. This is in contrast to α2M and probably due to the more limited cross-linking potential of IgM. Nevertheless, we show that IgM works synergistically with α2M and markedly lowers the concentration of α2M required for rosetting. Finally, HB3VAR06+ IEs share the capacity to bind α2M with subsets of genotypically distinct P. falciparum isolates forming rosettes in vitro and of patient parasite isolates ex vivo. Together, our results are evidence that P. falciparum parasites exploit α2M (and IgM) to expand the repertoire of host receptors available for PfEMP1-mediated IE adhesion, such as the erythrocyte carbohydrate moieties that lead to formation of rosettes. It is likely that this mechanism also affects IE adhesion to receptors on vascular endothelium. The study opens opportunities for broad-ranging immunological interventions targeting the α2M--(and IgM-) binding domains of PfEMP1, which would be independent of the host receptor specificity of clinically important PfEMP1 antigens.
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Affiliation(s)
- Liz Stevenson
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Erik Laursen
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Graeme J. Cowan
- Institute of Immunology and Infection Research, Center for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Betty Bandoh
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | - Lea Barfod
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - David R. Cavanagh
- Institute of Immunology and Infection Research, Center for Immunity, Infection and Evolution, University of Edinburgh, Edinburgh, United Kingdom
| | - Gregers R. Andersen
- Department of Molecular Biology and Genetics, University of Aarhus, Aarhus, Denmark
| | - Lars Hviid
- Centre for Medical Parasitology, Department of Immunology and Microbiology (ISIM), Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
- * E-mail:
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19
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McLEAN ARD, ATAIDE R, SIMPSON JA, BEESON JG, FOWKES FJI. Malaria and immunity during pregnancy and postpartum: a tale of two species. Parasitology 2015; 142:999-1015. [PMID: 25731914 PMCID: PMC4453920 DOI: 10.1017/s0031182015000074] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/19/2014] [Accepted: 01/16/2015] [Indexed: 11/07/2022]
Abstract
It is well established that pregnant women are at an increased risk of Plasmodium falciparum infection when compared to non-pregnant individuals and limited epidemiological data suggest Plasmodium vivax risk also increases with pregnancy. The risk of P. falciparum declines with successive pregnancies due to the acquisition of immunity to pregnancy-specific P. falciparum variants. However, despite similar declines in P. vivax risk with successive pregnancies, there is a paucity of evidence P. vivax-specific immunity. Cross-species immunity, as well as immunological and physiological changes that occur during pregnancy may influence the susceptibility to both P. vivax and P. falciparum. The period following delivery, the postpartum period, is relatively understudied and available epidemiological data suggests that it may also be a period of increased risk of infection to Plasmodium spp. Here we review the literature and directly compare and contrast the epidemiology, clinical pathogenesis and immunological features of P. vivax and P. falciparum in pregnancy, with a particular focus on studies performed in areas co-endemic for both species. Furthermore, we review the intriguing epidemiology literature of both P. falciparum and P. vivax postpartum and relate observations to the growing literature pertaining to malaria immunology in the postpartum period.
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Affiliation(s)
- A. R. D. McLEAN
- Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Melbourne, Victoria 3004, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - R. ATAIDE
- Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Melbourne, Victoria 3004, Australia
| | - J. A. SIMPSON
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
| | - J. G. BEESON
- Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Melbourne, Victoria 3004, Australia
- Department of Microbiology, Monash University, Melbourne, Victoria, Australia
- Department of Medicine, University of Melbourne, Melbourne, Victoria, Australia
| | - F. J. I. FOWKES
- Macfarlane Burnet Institute of Medical Research, 85 Commercial Road, Melbourne, Victoria 3004, Australia
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia
- Department of Epidemiology and Preventive Medicine and Department of Infectious Diseases, Monash University, Commercial Road, Melbourne, Victoria 3004, Australia
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Abstract
INTRODUCTION Placental malaria (PM) is a major public health problem that constitutes a significant health concern for the mother, and especially for the developing fetus and offspring. Current means of prevention have limitations, including a restricted window of intervention that excludes the first trimester of pregnancy, and the fact that very few drugs can be used for this purpose. The identification of the VAR2CSA antigen, specific to PM parasites, offers an excellent opportunity to develop a vaccine against this disease. Proof of concept of a first-generation vaccine is nearing completion, and two clinical trials are underway. AREAS COVERED This review focuses on PM, which is mainly caused by Plasmodium falciparum. The review highlights recent advances and the key milestones that led to the identification of the optimal vaccine target within the large VAR2CSA protein. The paper also points out how future improvements can strengthen this process to achieve an effective vaccine in the field. EXPERT OPINION The approach taken to develop a P. falciparum erythrocyte membrane protein 1-based vaccine to protect pregnant women is very promising in view of the current difficulties of achieving a sterilizing vaccine against malaria parasite. This approach could help us to control the deleterious effect of malaria infections that characterize severe clinical forms.
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Hviid L, Barfod L, Fowkes FJI. Trying to remember: immunological B cell memory to malaria. Trends Parasitol 2015; 31:89-94. [PMID: 25596801 DOI: 10.1016/j.pt.2014.12.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 12/16/2014] [Accepted: 12/17/2014] [Indexed: 11/17/2022]
Abstract
In areas with stable transmission of Plasmodium falciparum parasites, even partially-protective immunity to malaria is acquired only after years of exposure and several infections. It has long been speculated that malaria parasites are directly able to undermine the establishment and maintenance of immunological memory, and that the often transient antibody responses to this parasite are evidence of such a dysfunction. We propose that long-lived antibody responses may not always be a prerequisite for protection, and that antibody longevity varies in an exposure- and age-dependent manner.
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Affiliation(s)
- Lars Hviid
- Centre for Medical Parasitology at Institute for Medical Microbiology and Immunology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark.
| | - Lea Barfod
- Centre for Medical Parasitology at Institute for Medical Microbiology and Immunology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Freya J I Fowkes
- Macfarlane Burnet Institute of Medical Research, Melbourne, Victoria, Australia; Centre for Epidemiology and Biostatistics, University of Melbourne, Australia; Department of Epidemiology and Preventive Medicine and Department of Infectious Diseases, Monash University, Melbourne, Australia
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Ampomah P, Stevenson L, Ofori MF, Barfod L, Hviid L. Kinetics of B cell responses to Plasmodium falciparum erythrocyte membrane protein 1 in Ghanaian women naturally exposed to malaria parasites. THE JOURNAL OF IMMUNOLOGY 2014; 192:5236-44. [PMID: 24760153 DOI: 10.4049/jimmunol.1400325] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Naturally acquired protective immunity to Plasmodium falciparum malaria takes years to develop. It relies mainly on Abs, particularly IgG specific for Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) proteins on the infected erythrocyte surface. It is only partially understood why acquisition of clinical protection takes years to develop, but it probably involves a range of immune-evasive parasite features, not least of which are PfEMP1 polymorphism and clonal variation. Parasite-induced subversion of immunological memory and expansion of "atypical" memory B cells may also contribute. In this first, to our knowledge, longitudinal study of its kind, we measured B cell subset composition, as well as PfEMP1-specific Ab levels and memory B cell frequencies, in Ghanaian women followed from early pregnancy up to 1 y after delivery. Cell phenotypes and Ag-specific B cell function were assessed three times during and after pregnancy. Levels of IgG specific for pregnancy-restricted, VAR2CSA-type PfEMP1 increased markedly during pregnancy and declined after delivery, whereas IgG levels specific for two PfEMP1 proteins not restricted to pregnancy did not. Changes in VAR2CSA-specific memory B cell frequencies showed typical primary memory induction among primigravidae and recall expansion among multigravidae, followed by contraction postpartum in all. No systematic changes in the frequencies of memory B cells specific for the two other PfEMP1 proteins were identified. The B cell subset analysis confirmed earlier reports of high atypical memory B cell frequencies among residents of P. falciparum-endemic areas, and indicated an additional effect of pregnancy. Our study provides new knowledge regarding immunity to P. falciparum malaria and underpins efforts to develop PfEMP1-based vaccines against this disease.
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Affiliation(s)
- Paulina Ampomah
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen Ø, Denmark; and
| | - Liz Stevenson
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen Ø, Denmark; and
| | - Michael F Ofori
- Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Lea Barfod
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen Ø, Denmark; and
| | - Lars Hviid
- Centre for Medical Parasitology, University of Copenhagen and Copenhagen University Hospital (Rigshospitalet), 2100 Copenhagen Ø, Denmark; and
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