1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Talundzic E, Scott S, Owino SO, Campo DS, Lucchi NW, Udhayakumar V, Moore JM, Peterson DS. Polymorphic Molecular Signatures in Variable Regions of the Plasmodium falciparum var2csa DBL3x Domain Are Associated with Virulence in Placental Malaria. Pathogens 2022; 11:520. [PMID: 35631041 PMCID: PMC9147263 DOI: 10.3390/pathogens11050520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/15/2022] [Accepted: 04/24/2022] [Indexed: 11/17/2022] Open
Abstract
The Plasmodium falciparum protein VAR2CSA allows infected erythrocytes to accumulate within the placenta, inducing pathology and poor birth outcomes. Multiple exposures to placental malaria (PM) induce partial immunity against VAR2CSA, making it a promising vaccine candidate. However, the extent to which VAR2CSA genetic diversity contributes to immune evasion and virulence remains poorly understood. The deep sequencing of the var2csa DBL3X domain in placental blood from forty-nine primigravid and multigravid women living in malaria-endemic western Kenya revealed numerous unique sequences within individuals in association with chronic PM but not gravidity. Additional analysis unveiled four distinct sequence types that were variably present in mixed proportions amongst the study population. An analysis of the abundance of each of these sequence types revealed that one was inversely related to infant gestational age, another was inversely related to placental parasitemia, and a third was associated with chronic PM. The categorization of women according to the type to which their dominant sequence belonged resulted in the segregation of types as a function of gravidity: two types predominated in multigravidae whereas the other two predominated in primigravidae. The univariate logistic regression analysis of sequence type dominance further revealed that gravidity, maternal age, placental parasitemia, and hemozoin burden (within maternal leukocytes), reported a lack of antimalarial drug use, and infant gestational age and birth weight influenced the odds of membership in one or more of these sequence predominance groups. Cumulatively, these results show that unique var2csa sequences differentially appear in women with different PM exposure histories and segregate to types independently associated with maternal factors, infection parameters, and birth outcomes. The association of some var2csa sequence types with indicators of pathogenesis should motivate vaccine efforts to further identify and target VAR2CSA epitopes associated with maternal morbidity and poor birth outcomes.
Collapse
Affiliation(s)
- Eldin Talundzic
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (E.T.); (N.W.L.); (V.U.)
| | - Stephen Scott
- Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA;
| | - Simon O. Owino
- Boehringer Ingelheim Animal Health, Athens, GA 30601, USA;
| | - David S. Campo
- Molecular Epidemiology and Bioinformatics Laboratory, Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA;
| | - Naomi W. Lucchi
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (E.T.); (N.W.L.); (V.U.)
| | - Venkatachalam Udhayakumar
- Malaria Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA 30329, USA; (E.T.); (N.W.L.); (V.U.)
| | - Julie M. Moore
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL 32611, USA
| | - David S. Peterson
- Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA;
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA 30602, USA
| |
Collapse
|
3
|
Gamain B, Dorin-Semblat D. Extraction and Immunoprecipitation of VAR2CSA, the PfEMP1 Associated with Placental Malaria. Methods Mol Biol 2022; 2470:257-271. [PMID: 35881351 DOI: 10.1007/978-1-0716-2189-9_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a key virulence factor for this human malaria parasite. During pregnancy, VAR2CSA is the only PfEMP1 variant expressed on the surface of infected erythrocytes that mediates adhesion to placenta cells and causes severe pregnancy outcomes.In this chapter, we present an optimized protocol to extract and immunoprecipitate endogenous VAR2CSA from the infected erythrocyte membrane phospholipid bilayer environment for subsequent characterization of the central role of VAR2CSA in placental malaria.
Collapse
|
4
|
Tornyigah B, d'Almeida T, Escriou G, Viwami F, Fievet N, Luty AJF, Massougbodji A, Nielsen MA, Deloron P, Tuikue Ndam N. Plasmodium falciparum VAR2CSA-Specific IgG Subclass Responses Reflect Protection Against Low Birth Weight and Pregnancy-Associated Malaria. Front Immunol 2021; 12:610305. [PMID: 33968015 PMCID: PMC8099026 DOI: 10.3389/fimmu.2021.610305] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 03/31/2021] [Indexed: 11/13/2022] Open
Abstract
Sequestration of Plasmodium falciparum-infected erythrocytes expressing the VAR2CSA antigen in the placenta results in poor pregnancy outcomes, including low birth weight and maternal anemia. Antigen-specific antibody-mediated immunity is acquired during successive pregnancies. Thus, evaluating VAR2CSA-specific IgG profiles among pregnant women will increase knowledge on the immunological mechanisms associated with protection, and help in the development of VAR2CSA-based placental malaria vaccines. Using the PAMVAC candidate vaccine antigen, we assessed anti-VAR2CSA IgG subclass responses of a cohort of pregnant Beninese, and analyzed their relationships with pregnancy outcomes. Cytophilic IgG1 and IgG3 responses were the most frequent, with prevalences ranging from 28% (IgG3) up to 50% (IgG1). Elevated levels of VAR2CSA-specific total IgG and cytophilic IgG3 during pregnancy were consistently associated with higher birth weights, whilst high levels of IgG4 were associated with a reduced risk of placental infections. This suggests that protective anti-VAR2CSA IgG responses are coordinated between both cytophilic and non-cytophilic antibodies.
Collapse
Affiliation(s)
- Bernard Tornyigah
- Université de Paris, MERIT, IRD, Paris, France.,Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Tania d'Almeida
- Université de Paris, MERIT, IRD, Paris, France.,Université Pierre et Marie Curie, Ecole doctorale 393 Pierre Louis de Santé publique, Paris, France
| | | | - Firmine Viwami
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Nadine Fievet
- Université de Paris, MERIT, IRD, Paris, France.,Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Adrian J F Luty
- Université de Paris, MERIT, IRD, Paris, France.,Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Achille Massougbodji
- Centre d'Etude et de Recherche sur le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Morten A Nielsen
- Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark
| | | | - Nicaise Tuikue Ndam
- Université de Paris, MERIT, IRD, Paris, France.,Department of Immunology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| |
Collapse
|
5
|
Gamain B, Chêne A, Viebig NK, Tuikue Ndam N, Nielsen MA. Progress and Insights Toward an Effective Placental Malaria Vaccine. Front Immunol 2021; 12:634508. [PMID: 33717176 PMCID: PMC7947914 DOI: 10.3389/fimmu.2021.634508] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/06/2021] [Indexed: 12/03/2022] Open
Abstract
In areas where Plasmodium falciparum transmission is endemic, clinical immunity against malaria is progressively acquired during childhood and adults are usually protected against the severe clinical consequences of the disease. Nevertheless, pregnant women, notably during their first pregnancies, are susceptible to placental malaria and the associated serious clinical outcomes. Placental malaria is characterized by the massive accumulation of P. falciparum infected erythrocytes and monocytes in the placental intervillous spaces leading to maternal anaemia, hypertension, stillbirth and low birth weight due to premature delivery, and foetal growth retardation. Remarkably, the prevalence of placental malaria sharply decreases with successive pregnancies. This protection is associated with the development of antibodies directed towards the surface of P. falciparum-infected erythrocytes from placental origin. Placental sequestration is mediated by the interaction between VAR2CSA, a member of the P. falciparum erythrocyte membrane protein 1 family expressed on the infected erythrocytes surface, and the placental receptor chondroitin sulfate A. VAR2CSA stands today as the leading candidate for a placental malaria vaccine. We recently reported the safety and immunogenicity of two VAR2CSA-derived placental malaria vaccines (PRIMVAC and PAMVAC), spanning the chondroitin sulfate A-binding region of VAR2CSA, in both malaria-naïve and P. falciparum-exposed non-pregnant women in two distinct Phase I clinical trials (ClinicalTrials.gov, NCT02658253 and NCT02647489). This review discusses recent advances in placental malaria vaccine development, with a focus on the recent clinical data, and discusses the next clinical steps to undertake in order to better comprehend vaccine-induced immunity and accelerate vaccine development.
Collapse
Affiliation(s)
- Benoît Gamain
- Université de Paris, Inserm, Biologie Intégrée du Globule Rouge, Paris, France.,Institut National de la Transfusion Sanguine, Paris, France
| | - Arnaud Chêne
- Université de Paris, Inserm, Biologie Intégrée du Globule Rouge, Paris, France.,Institut National de la Transfusion Sanguine, Paris, France
| | - Nicola K Viebig
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Heidelberg, Germany
| | | | - Morten A Nielsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Rigshospitalet, Copenhagen, Denmark
| |
Collapse
|
6
|
Doritchamou JYA, Suurbaar J, Tuikue Ndam N. Progress and new horizons toward a VAR2CSA-based placental malaria vaccine. Expert Rev Vaccines 2021; 20:215-226. [PMID: 33472449 DOI: 10.1080/14760584.2021.1878029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Introduction: Several malaria vaccines are under various phases of development with some promising results. In placental malaria (PM) a deliberately anti-disease approach is considered as many studies have underlined the key role of VAR2CSA protein, which therefore represents the leading vaccine candidate. However, evidence indicates that VAR2CSA antigenic polymorphism remains an obstacle to overcome.Areas covered: This review analyzes the progress made thus far in developing a VAR2CSA-based vaccine, and addresses the current issues and challenges that must be overcome to develop an effective PM vaccine.Expert opinion: Phase I trials of PAMVAC and PRIMVAC VAR2CSA vaccines have shown more or less satisfactory results with regards to safety and immunogenicity. The second generation of VAR2CSA-based vaccines could benefit from optimization approaches to broaden the activity spectrum against various placenta-binding isolates through continued advances in the structural understanding of the interaction with CSA.
Collapse
Affiliation(s)
- Justin Yai Alamou Doritchamou
- Laboratory of Malaria Immunology & Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jennifer Suurbaar
- Université de Paris, MERIT, IRD, F-75006 Paris, France.,Noguchi Memorial Institute for Medical Research, Department of Immunology, University of Ghana, Accra, Ghana
| | - Nicaise Tuikue Ndam
- Université de Paris, MERIT, IRD, F-75006 Paris, France.,Noguchi Memorial Institute for Medical Research, Department of Immunology, University of Ghana, Accra, Ghana
| |
Collapse
|
7
|
Gnidehou S, Yanow SK. VAR2CSA Antibodies in Non-Pregnant Populations. Trends Parasitol 2020; 37:65-76. [PMID: 33067131 DOI: 10.1016/j.pt.2020.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 11/18/2022]
Abstract
The Plasmodium falciparum protein VAR2CSA is a critical mediator of placental malaria, and VAR2CSA antibodies (IgGs) are important to protect pregnant women. Although infrequently detected outside pregnancy, VAR2CSA IgGs were reported in men and children from Colombia and Brazil and in select African populations. These findings raise questions about the specificity of VAR2CSA IgGs and the mechanisms by which they are acquired outside pregnancy. Here we review the data on VAR2CSA IgGs in men and children from different malaria-endemic regions. We discuss experimental factors that may affect interpretation of the serological data and consider the biological relevance of VAR2CSA IgGs in non-pregnant populations. We propose potential mechanisms for the acquisition of VARCSA IgGs outside of pregnancy. We identify knowledge gaps and research priorities.
Collapse
Affiliation(s)
- Sedami Gnidehou
- Campus Saint-Jean, University of Alberta, Edmonton, AB, Canada; Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada.
| | - Stephanie K Yanow
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada; School of Public Health, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
8
|
Mordmüller B, Sulyok M, Egger-Adam D, Resende M, de Jongh WA, Jensen MH, Smedegaard HH, Ditlev SB, Soegaard M, Poulsen L, Dyring C, Calle CL, Knoblich A, Ibáñez J, Esen M, Deloron P, Ndam N, Issifou S, Houard S, Howard RF, Reed SG, Leroy O, Luty AJF, Theander TG, Kremsner PG, Salanti A, Nielsen MA. First-in-human, Randomized, Double-blind Clinical Trial of Differentially Adjuvanted PAMVAC, A Vaccine Candidate to Prevent Pregnancy-associated Malaria. Clin Infect Dis 2020; 69:1509-1516. [PMID: 30629148 PMCID: PMC6792113 DOI: 10.1093/cid/ciy1140] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 01/03/2019] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Malaria in pregnancy has major impacts on mother and child health. To complement existing interventions, such as intermittent preventive treatment and use of impregnated bed nets, we developed a malaria vaccine candidate with the aim of reducing sequestration of asexual "blood-stage" parasites in the placenta, the major virulence mechanism. METHODS The vaccine candidate PAMVAC is based on a recombinant fragment of VAR2CSA, the Plasmodium falciparum protein responsible for binding to the placenta via chondroitin sulfate A (CSA). Healthy, adult malaria-naive volunteers were immunized with 3 intramuscular injections of 20 μg (n = 9) or 50 μg (n = 27) PAMVAC, adjuvanted with Alhydrogel or glucopyranosyl lipid adjuvant in stable emulsion (GLA-SE) or in a liposomal formulation with QS21 (GLA-LSQ). Allocation was random and double blind. The vaccine was given every 4 weeks. Volunteers were observed for 6 months following last immunization. RESULTS All PAMVAC formulations were safe and well tolerated. A total of 262 adverse events (AEs) occurred, 94 (10 grade 2 and 2 grade 3) at least possibly related to the vaccine. No serious AEs occurred. Distribution and severity of AEs were similar in all arms. PAMVAC was immunogenic in all participants. PAMVAC-specific antibody levels were highest with PAMVAC-GLA-SE. The antibodies inhibited binding of VAR2CSA expressing P. falciparum-infected erythrocytes to CSA in a standardized functional assay. CONCLUSIONS PAMVAC formulated with Alhydrogel or GLA-based adjuvants was safe, well tolerated, and induced functionally active antibodies. Next, PAMVAC will be assessed in women before first pregnancies in an endemic area. CLINICAL TRIALS REGISTRATION EudraCT 2015-001827-21; ClinicalTrials.gov NCT02647489.
Collapse
Affiliation(s)
- Benjamin Mordmüller
- Institut für Tropenmedizin, Universitätsklinikum Tübingen and Deutsches Zentrum für Infektionsforschung, Germany.,Centre de Recherches Médicales de Lambaréné, Gabon
| | - Mihály Sulyok
- Institut für Tropenmedizin, Universitätsklinikum Tübingen and Deutsches Zentrum für Infektionsforschung, Germany
| | - Diane Egger-Adam
- Institut für Tropenmedizin, Universitätsklinikum Tübingen and Deutsches Zentrum für Infektionsforschung, Germany
| | - Mafalda Resende
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital
| | | | - Mette H Jensen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital
| | - Helle Holm Smedegaard
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital
| | - Sisse B Ditlev
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital
| | | | | | | | - Carlos Lamsfus Calle
- Institut für Tropenmedizin, Universitätsklinikum Tübingen and Deutsches Zentrum für Infektionsforschung, Germany
| | - Annette Knoblich
- Institut für Tropenmedizin, Universitätsklinikum Tübingen and Deutsches Zentrum für Infektionsforschung, Germany
| | - Javier Ibáñez
- Institut für Tropenmedizin, Universitätsklinikum Tübingen and Deutsches Zentrum für Infektionsforschung, Germany
| | - Meral Esen
- Institut für Tropenmedizin, Universitätsklinikum Tübingen and Deutsches Zentrum für Infektionsforschung, Germany.,Centre de Recherches Médicales de Lambaréné, Gabon
| | - Philippe Deloron
- Mère et Enfant face aux Infections Tropicales, Institut de Recherche pour le Développement, Université Paris 5, Sorbonne Paris Cité, France
| | - Nicaise Ndam
- Mère et Enfant face aux Infections Tropicales, Institut de Recherche pour le Développement, Université Paris 5, Sorbonne Paris Cité, France
| | - Saadou Issifou
- Fondation pour la Recherche Scientifique and Institut de Recherche Clinique du Bénin, Cotonou
| | | | | | - Steven G Reed
- Infectious Disease Research Institute, Seattle, Washington
| | - Odile Leroy
- European Vaccine Initiative, Heidelberg, Germany
| | - Adrian J F Luty
- Mère et Enfant face aux Infections Tropicales, Institut de Recherche pour le Développement, Université Paris 5, Sorbonne Paris Cité, France
| | - Thor G Theander
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital
| | - Peter G Kremsner
- Institut für Tropenmedizin, Universitätsklinikum Tübingen and Deutsches Zentrum für Infektionsforschung, Germany.,Centre de Recherches Médicales de Lambaréné, Gabon
| | - Ali Salanti
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital
| | - Morten A Nielsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital
| |
Collapse
|
9
|
Salamanca DR, Gómez M, Camargo A, Cuy-Chaparro L, Molina-Franky J, Reyes C, Patarroyo MA, Patarroyo ME. Plasmodium falciparum Blood Stage Antimalarial Vaccines: An Analysis of Ongoing Clinical Trials and New Perspectives Related to Synthetic Vaccines. Front Microbiol 2019; 10:2712. [PMID: 31849871 PMCID: PMC6901501 DOI: 10.3389/fmicb.2019.02712] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 11/08/2019] [Indexed: 01/10/2023] Open
Abstract
Plasmodium falciparum malaria is a disease causing high morbidity and mortality rates worldwide, mainly in sub-Saharan Africa. Candidates have been identified for vaccines targeting the parasite's blood stage; this stage is important in the development of symptoms and clinical complications. However, no vaccine that can directly affect morbidity and mortality rates is currently available. This review analyzes the formulation, methodological design, and results of active clinical trials for merozoite-stage vaccines, regarding their safety profile, immunological response (phase Ia/Ib), and protective efficacy levels (phase II). Most vaccine candidates are in phase I trials and have had an acceptable safety profile. GMZ2 has made the greatest progress in clinical trials; its efficacy has been 14% in children aged less than 5 years in a phase IIb trial. Most of the available candidates that have shown strong immunogenicity and that have been tested for their protective efficacy have provided good results when challenged with a homologous parasite strain; however, their efficacy has dropped when they have been exposed to a heterologous strain. In view of these vaccines' unpromising results, an alternative approach for selecting new candidates is needed; such line of work should be focused on how to increase an immune response induced against the highly conserved (i.e., common to all strains), functionally relevant, protein regions that the parasite uses to invade target cells. Despite binding regions tending to be conserved, they are usually poorly antigenic and/or immunogenic, being frequently discarded as vaccine candidates when the conventional immunological approach is followed. The Fundación Instituto de Inmunología de Colombia (FIDIC) has developed a logical and rational methodology based on including conserved high-activity binding peptides (cHABPs) from the main P. falciparum biologically functional proteins involved in red blood cell (RBC) invasion. Once appropriately modified (mHABPs), these minimal, subunit-based, chemically synthesized peptides can be used in a system covering the human immune system's main genetic variables (the human leukocyte antigen HLA-DR isotype) inducing a suitable, immunogenic, and protective immune response in most of the world's populations.
Collapse
Affiliation(s)
- David Ricardo Salamanca
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Marcela Gómez
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Anny Camargo
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Laura Cuy-Chaparro
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - Jessica Molina-Franky
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia.,Medicine Programme, Health Sciences Faculty, Universidad de Boyacá, Tunja, Colombia
| | - César Reyes
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Ph.D. Programme in Biomedical and Biological Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Manuel Alfonso Patarroyo
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Basic Sciences Department, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Manuel Elkin Patarroyo
- Fundación Instituto de Inmunología de Colombia, Bogotá, Colombia.,Department of Pathology, School of Medicine, Universidad Nacional de Colombia, Boyacá, Colombia
| |
Collapse
|
10
|
Chêne A, Gangnard S, Guadall A, Ginisty H, Leroy O, Havelange N, Viebig NK, Gamain B. Preclinical immunogenicity and safety of the cGMP-grade placental malaria vaccine PRIMVAC. EBioMedicine 2019; 42:145-156. [PMID: 30885725 PMCID: PMC6491931 DOI: 10.1016/j.ebiom.2019.03.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/26/2019] [Accepted: 03/04/2019] [Indexed: 11/28/2022] Open
Abstract
Background VAR2CSA is the lead antigen for developing a vaccine that would protect pregnant women against placental malaria. A multi-system feasibility study has identified E. coli as a suitable bacterial expression platform allowing the production of recombinant VAR2CSA-DBL1x-2x (PRIMVAC) to envisage a prompt transition to current Good Manufacturing Practice (cGMP) vaccine production. Methods Extensive process developments were undertaken to produce cGMP grade PRIMVAC to permit early phase clinical trials. PRIMVAC stability upon storage was assessed over up to 3 years. A broad toxicology investigation was carried out in rats allowing meanwhile the analysis of PRIMVAC immunogenicity. Findings We describe the successful cGMP production of 4. 65 g of PRIMVAC. PRIMVAC drug product was stable and potent for up to 3 years upon storage at −20 °C and showed an absence of toxicity in rats. PRIMVAC adjuvanted with Alhydrogel® or GLA-SE was able to generate antibodies able to recognize VAR2CSA expressed at the surface of erythrocytes infected with different strains. These antibodies also inhibit the interaction of the homologous NF54-CSA strain and to a lower extend of heterologous strains to CSA. Interpretation This work paved the way for the clinical development of an easily scalable low cost effective vaccine that could protect against placental malaria and prevent an estimated 10,000 maternal and 200,000 infant deaths annually. Fund This work was supported by a grant from the Bundesministerium für Bildung und Forschung (BMBF), Germany through Kreditanstalt für Wiederaufbau (KfW) (Reference No: 202060457) and through funding from Irish Aid, Department of Foreign Affairs and Trade, Ireland.
Collapse
Affiliation(s)
- Arnaud Chêne
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge UMR_S1134, Severe Malaria Pathogenesis group, Laboratoire d'Excellence GR-Ex, Paris, France
| | - Stéphane Gangnard
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge UMR_S1134, Severe Malaria Pathogenesis group, Laboratoire d'Excellence GR-Ex, Paris, France
| | - Anna Guadall
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge UMR_S1134, Severe Malaria Pathogenesis group, Laboratoire d'Excellence GR-Ex, Paris, France
| | - Hervé Ginisty
- GTP Technology, l'Occitane, 31670 Labège, Cedex, France
| | - Odile Leroy
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Voßstraße 2, 69115 Heidelberg, Germany
| | - Nicolas Havelange
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Voßstraße 2, 69115 Heidelberg, Germany
| | - Nicola K Viebig
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Voßstraße 2, 69115 Heidelberg, Germany
| | - Benoît Gamain
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge UMR_S1134, Severe Malaria Pathogenesis group, Laboratoire d'Excellence GR-Ex, Paris, France.
| |
Collapse
|
11
|
Seitz J, Morales-Prieto DM, Favaro RR, Schneider H, Markert UR. Molecular Principles of Intrauterine Growth Restriction in Plasmodium Falciparum Infection. Front Endocrinol (Lausanne) 2019; 10:98. [PMID: 30930847 PMCID: PMC6405475 DOI: 10.3389/fendo.2019.00098] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 02/01/2019] [Indexed: 12/21/2022] Open
Abstract
Malaria in pregnancy still constitutes a particular medical challenge in tropical and subtropical regions. Of the five Plasmodium species that are pathogenic to humans, infection with Plasmodium falciparum leads to fulminant progression of the disease with massive impact on pregnancy. Severe anemia of the mother, miscarriage, stillbirth, preterm delivery and intrauterine growth restriction (IUGR) with reduced birth weight are frequent complications that lead to more than 10,000 maternal and 200,000 perinatal deaths annually in sub-Saharan Africa alone. P. falciparum can adhere to the placenta via the expression of the surface antigen VAR2CSA, which leads to sequestration of infected erythrocytes in the intervillous space. This process induces a placental inflammation with involvement of immune cells and humoral factors. Especially, monocytes get activated and change the release of soluble mediators, including a variety of cytokines. This proinflammatory environment contributes to disorders of angiogenesis, blood flow, autophagy, and nutrient transport in the placenta and erythropoiesis. Collectively, they impair placental functions and, consequently, fetal growth. The discovery that women in endemic regions develop a certain immunity against VAR2CSA-expressing parasites with increasing number of pregnancies has redefined the understanding of malaria in pregnancy and offers strategies for the development of vaccines. The following review gives an overview of molecular processes in P. falciparum infection in pregnancy which may be involved in the development of IUGR.
Collapse
Affiliation(s)
- Johanna Seitz
- Placenta Lab, Department of Obstetrics, Jena University Hospital, Jena, Germany
| | | | - Rodolfo R. Favaro
- Placenta Lab, Department of Obstetrics, Jena University Hospital, Jena, Germany
| | - Henning Schneider
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
- Department of Obstetrics and Gynecology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Udo Rudolf Markert
- Placenta Lab, Department of Obstetrics, Jena University Hospital, Jena, Germany
| |
Collapse
|
12
|
Abstract
The blood stage of the malaria parasite life cycle is responsible for all the clinical symptoms of malaria. During the blood stage, Plasmodium merozoites invade and multiply within host red blood cells (RBCs). Here, we review the progress made, challenges faced, and new strategies available for the development of blood stage malaria vaccines. We discuss our current understanding of immune responses against blood stages and the status of clinical development of various blood stage malaria vaccine candidates. We then discuss possible paths forward to develop effective blood stage malaria vaccines. This includes a discussion of protective immune mechanisms that can be elicited to target blood stage parasites, novel delivery systems, immunoassays and animal models to optimize vaccine candidates in preclinical studies, and use of challenge models to get an early readout of vaccine efficacy.
Collapse
|
13
|
Ubillos I, Jiménez A, Vidal M, Bowyer PW, Gaur D, Dutta S, Gamain B, Coppel R, Chauhan V, Lanar D, Chitnis C, Angov E, Beeson J, Cavanagh D, Campo JJ, Aguilar R, Dobaño C. Optimization of incubation conditions of Plasmodium falciparum antibody multiplex assays to measure IgG, IgG 1-4, IgM and IgE using standard and customized reference pools for sero-epidemiological and vaccine studies. Malar J 2018; 17:219. [PMID: 29859096 PMCID: PMC5984756 DOI: 10.1186/s12936-018-2369-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/28/2018] [Indexed: 12/15/2022] Open
Abstract
Background The quantitative suspension array technology (qSAT) is a useful platform for malaria immune marker discovery. However, a major challenge for large sero-epidemiological and malaria vaccine studies is the comparability across laboratories, which requires the access to standardized control reagents for assay optimization, to monitor performance and improve reproducibility. Here, the Plasmodium falciparum antibody reactivities of the newly available WHO reference reagent for anti-malaria human plasma (10/198) and of additional customized positive controls were examined with seven in-house qSAT multiplex assays measuring IgG, IgG1–4 subclasses, IgM and IgE against a panel of 40 antigens. The different positive controls were tested at different incubation times and temperatures (4 °C overnight, 37 °C 2 h, room temperature 1 h) to select the optimal conditions. Results Overall, the WHO reference reagent had low IgG2, IgG4, IgM and IgE, and also low anti-CSP antibody levels, thus this reagent was enriched with plasmas from RTS,S-vaccinated volunteers to be used as standard for CSP-based vaccine studies. For the IgM assay, another customized plasma pool prepared with samples from malaria primo-infected adults with adequate IgM levels proved to be more adequate as a positive control. The range and magnitude of IgG and IgG1–4 responses were highest when the WHO reference reagent was incubated with antigen-coupled beads at 4 °C overnight. IgG levels measured in the negative control did not vary between incubations at 37 °C 2 h and 4 °C overnight, indicating no difference in unspecific binding. Conclusions With this study, the immunogenicity profile of the WHO reference reagent, including seven immunoglobulin isotypes and subclasses, and more P. falciparum antigens, also those included in the leading RTS,S malaria vaccine, was better characterized. Overall, incubation of samples at 4 °C overnight rendered the best performance for antibody measurements against the antigens tested. Although the WHO reference reagent performed well to measure IgG to the majority of the common P. falciparum blood stage antigens tested, customized pools may need to be used as positive controls depending on the antigens (e.g. pre-erythrocytic proteins of low natural immunogenicity) and isotypes/subclasses (e.g. IgM) under study. Electronic supplementary material The online version of this article (10.1186/s12936-018-2369-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Itziar Ubillos
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain
| | - Alfons Jiménez
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain.,CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, Spain
| | - Marta Vidal
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain
| | - Paul W Bowyer
- Bacteriology Division, MHRA-NIBSC, South Mimms, Potter Bars, EN6 3QG, UK
| | - Deepak Gaur
- Laboratory of Malaria and Vaccine Research, School of Biotechnology, Jawaharlal Nehru University, New Delhi, India.,Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Sheetij Dutta
- U.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Benoit Gamain
- Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge UMR_S1134, Laboratoire d'Excellence GR-Ex, Paris, France
| | - Ross Coppel
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Virander Chauhan
- Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - David Lanar
- U.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - Chetan Chitnis
- Malaria Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Evelina Angov
- U.S. Military Malaria Vaccine Program, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | - James Beeson
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, VIC, Australia
| | - David Cavanagh
- Institute of Immunology & Infection Research and Centre for Immunity, Infection & Evolution, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, King's Buildings, Charlotte Auerbach Rd, Edinburgh, EH9 3FL, UK
| | - Joseph J Campo
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain
| | - Ruth Aguilar
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain
| | - Carlota Dobaño
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Carrer Rosselló 153 (CEK Building), 08036, Barcelona, Catalonia, Spain.
| |
Collapse
|
14
|
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.
Collapse
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
| |
Collapse
|
15
|
Abstract
One hundred and twenty-five million women in malaria-endemic areas become pregnant each year (see Dellicour et al. PLoS Med7: e1000221 [2010]) and require protection from infection to avoid disease and death for themselves and their offspring. Chloroquine prophylaxis was once a safe approach to prevention but has been abandoned because of drug-resistant parasites, and intermittent presumptive treatment with sulfadoxine-pyrimethamine, which is currently used to protect pregnant women throughout Africa, is rapidly losing its benefits for the same reason. No other drugs have yet been shown to be safe, tolerable, and effective as prevention for pregnant women, although monthly dihydroartemisinin-piperaquine has shown promise for reducing poor pregnancy outcomes. Insecticide-treated nets provide some benefits, such as reducing placental malaria and low birth weight. However, this leaves a heavy burden of maternal, fetal, and infant morbidity and mortality that could be avoided. Women naturally acquire resistance to Plasmodium falciparum over successive pregnancies as they acquire antibodies against parasitized red cells that bind chondroitin sulfate A in the placenta, suggesting that a vaccine is feasible. Pregnant women are an important reservoir of parasites in the community, and women of reproductive age must be included in any elimination effort, but several features of malaria during pregnancy will require special consideration during the implementation of elimination programs.
Collapse
Affiliation(s)
- Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD 20892
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD 20892
| |
Collapse
|
16
|
Antibody responses to the full-length VAR2CSA and its DBL domains in Cameroonian children and teenagers. Malar J 2016; 15:532. [PMID: 27814765 PMCID: PMC5097422 DOI: 10.1186/s12936-016-1585-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/28/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Antigenic variation of Plasmodium falciparum erythrocyte membrane protein 1 is a key parasite mechanism for immune evasion and parasite survival. It is assumed that the number of parasites expressing the same var gene must reach high enough numbers before the host can produce detectable levels of antibodies (Ab) to the variant. VAR2CSA is a protein coded for by one of 60 var genes that is expressed on the surface of infected erythrocytes (IE) and mediates IE binding to the placenta. The idea that Ab to VAR2CSA are pregnancy-associated was challenged when VAR2CSA-specific Ab were reported in children and men. However, the frequency and conditions under which Ab to VAR2CSA are produced outside pregnancy is unclear. This study sought to determine frequency, specificity and level of Ab to VAR2CSA produced in children and whether children with hyperparasitaemia and severe malaria are more likely to produce Ab to VAR2CSA compared to healthy children. METHODS Antibody responses to a panel of recombinant proteins consisting of multiple VAR2CSA Duffy-binding-like domains (DBL) and full-length VAR2CSA (FV2) were characterized in 193 1-15 year old children from rural Cameroonian villages and 160 children with severe malaria from the city. RESULTS Low Ab levels to VAR2CSA were detected in children; however, Ab levels to FV2 in teenagers were rare. Children preferentially recognized DBL2 (56-70%) and DBL4 (50-60%), while multigravidae produced high levels of IgG to DBL3, DBL5 and FV2. Sixty-seven percent of teenage girls (n = 16/24) recognized ID1-ID2a region of VAR2CSA. Children with severe forms of malaria had significantly higher IgG to merozoite antigens (all p < 0.05), but not to VAR2CSA (all p > 0.05) when compared to the healthy children. CONCLUSION The study suggests that children, including teenage girls acquire Ab to VAR2CSA domains and FV2, but Ab levels are much lower than those needed to protect women from placental infections and repertoire of Ab responses to DBL domains is different from those in pregnant women. Interestingly, children with severe malaria did not have higher Ab levels to VAR2CSA compared to healthy children.
Collapse
|
17
|
Chêne A, Houard S, Nielsen MA, Hundt S, D'Alessio F, Sirima SB, Luty AJF, Duffy P, Leroy O, Gamain B, Viebig NK. Clinical development of placental malaria vaccines and immunoassays harmonization: a workshop report. Malar J 2016; 15:476. [PMID: 27639691 PMCID: PMC5027113 DOI: 10.1186/s12936-016-1527-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 09/08/2016] [Indexed: 01/01/2023] Open
Abstract
Placental malaria caused by Plasmodium falciparum infection constitutes a major health problem manifesting as severe disease and anaemia in the mother, impaired fetal development, low birth weight or spontaneous abortion. Prevention of placental malaria currently relies on two key strategies that are losing efficacy due to spread of resistance: long-lasting insecticide-treated nets and intermittent preventive treatment during pregnancy. A placental malaria vaccine would be an attractive, cost-effective complement to the existing control tools. Two placental malaria vaccine candidates are currently in Phase Ia/b clinical trials. During two workshops hosted by the European Vaccine Initiative, one in Paris in April 2014 and the other in Brussels in November 2014, the main actors in placental malaria vaccine research discussed the harmonization of clinical development plans and of the immunoassays with a goal to define standards that will allow comparative assessment of different placental malaria vaccine candidates. The recommendations of these workshops should guide researchers and clinicians in the further development of placental malaria vaccines.
Collapse
Affiliation(s)
- Arnaud Chêne
- Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, Institut National de la Transfusion Sanguine, Paris, France
| | - Sophie Houard
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Voßstraße 2, 69115, Heidelberg, Germany
| | - Morten A Nielsen
- Centre for Medical Parasitology at Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Infectious Diseases, Copenhagen University Hospital (Rigshospitalet), Copenhagen, Denmark
| | - Sophia Hundt
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Voßstraße 2, 69115, Heidelberg, Germany
| | - Flavia D'Alessio
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Voßstraße 2, 69115, Heidelberg, Germany
| | - Sodiomon B Sirima
- Centre National de Recherche et de Formation sur le Paludisme, 01 BP 2208, Ouagadougou 01, Burkina Faso
| | - Adrian J F Luty
- IRD MERIT UMR 216, 75006, Paris, France.,COMUE Sorbonne Paris Cité, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, 75270, Paris, France
| | - Patrick Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Disease, National Institutes of Health, Rockville, MD, USA
| | - Odile Leroy
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Voßstraße 2, 69115, Heidelberg, Germany
| | - Benoit Gamain
- Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, Institut National de la Transfusion Sanguine, Paris, France
| | - Nicola K Viebig
- European Vaccine Initiative, UniversitätsKlinikum Heidelberg, Voßstraße 2, 69115, Heidelberg, Germany.
| |
Collapse
|
18
|
Teo A, Feng G, Brown GV, Beeson JG, Rogerson SJ. Functional Antibodies and Protection against Blood-stage Malaria. Trends Parasitol 2016; 32:887-898. [PMID: 27546781 DOI: 10.1016/j.pt.2016.07.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 07/09/2016] [Accepted: 07/14/2016] [Indexed: 01/06/2023]
Abstract
Numerous efforts to understand the functional roles of antibodies demonstrated that they can protect against malaria. However, it is unclear which antibody responses are the best correlates of immunity, and which antibody functions are most important in protection from disease. Understanding the role of antibodies in protection against malaria is crucial for antimalarial vaccine design. In this review, the specific functional properties of naturally acquired and vaccine-induced antibodies that correlate to protection from the blood stages of Plasmodium falciparum malaria are re-examined and the gaps in knowledge related to antibody function in malarial immunity are highlighted.
Collapse
Affiliation(s)
- Andrew Teo
- Department of Medicine, University of Melbourne (Royal Melbourne Hospital), Parkville, Australia; Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia
| | - Gaoqian Feng
- Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Australia
| | - Graham V Brown
- Department of Medicine, University of Melbourne (Royal Melbourne Hospital), Parkville, Australia; Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia; Victorian Infectious Diseases Service, Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - James G Beeson
- Department of Medicine, University of Melbourne (Royal Melbourne Hospital), Parkville, Australia; Burnet Institute for Medical Research and Public Health, 85 Commercial Road, Australia; Department of Microbiology, Monash University, Melbourne, Victoria, Australia
| | - Stephen J Rogerson
- Department of Medicine, University of Melbourne (Royal Melbourne Hospital), Parkville, Australia; Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Australia; Victorian Infectious Diseases Service, Doherty Institute for Infection and Immunity, Melbourne, Australia.
| |
Collapse
|
19
|
Dechavanne C, Cottrell G, Garcia A, Migot-Nabias F. Placental Malaria: Decreased Transfer of Maternal Antibodies Directed to Plasmodium falciparum and Impact on the Incidence of Febrile Infections in Infants. PLoS One 2015; 10:e0145464. [PMID: 26698578 PMCID: PMC4689360 DOI: 10.1371/journal.pone.0145464] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 12/03/2015] [Indexed: 12/15/2022] Open
Abstract
The efficacy of mother-to-child placental transfer of antibodies specific to malaria blood stage antigens was investigated in the context of placental malaria infection, taking into account IgG specificity and maternal hypergammaglobulinemia. The impact of the resulting maternal antibody transfer on infections in infants up to the age of 6 months was also explored. This study showed that i) placental malaria was associated with a reduced placental transfer of total and specific IgG, ii) antibody placental transfer varied according to IgG specificity and iii) cord blood malaria IgG levels were similar in infants born to mothers with or without placental malaria. The number of malaria infections was negatively associated with maternal age, whereas it was not associated with the transfer of any malaria-specific IgG from the mother to the fetus. These results suggest that i) malaria-specific IgG may serve as a marker of maternal exposure but not as a useful marker of infant protection from malaria and ii) increasing maternal age contributes to diminishing febrile infections diagnosed in infants, perhaps by means of the transmission of an effective antibody response.
Collapse
Affiliation(s)
- Celia Dechavanne
- Institut de Recherche pour le Développement (IRD), UMR 216 Mère et enfant face aux infections tropicales, Université Paris Descartes, Paris, France
- COMUE Sorbonne Paris Cité, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
- * E-mail:
| | - Gilles Cottrell
- Institut de Recherche pour le Développement (IRD), UMR 216 Mère et enfant face aux infections tropicales, Université Paris Descartes, Paris, France
- COMUE Sorbonne Paris Cité, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - André Garcia
- Institut de Recherche pour le Développement (IRD), UMR 216 Mère et enfant face aux infections tropicales, Université Paris Descartes, Paris, France
- COMUE Sorbonne Paris Cité, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| | - Florence Migot-Nabias
- Institut de Recherche pour le Développement (IRD), UMR 216 Mère et enfant face aux infections tropicales, Université Paris Descartes, Paris, France
- COMUE Sorbonne Paris Cité, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, Paris, France
| |
Collapse
|
20
|
Nunes-Silva S, Dechavanne S, Moussiliou A, Pstrąg N, Semblat JP, Gangnard S, Tuikue-Ndam N, Deloron P, Chêne A, Gamain B. Beninese children with cerebral malaria do not develop humoral immunity against the IT4-VAR19-DC8 PfEMP1 variant linked to EPCR and brain endothelial binding. Malar J 2015; 14:493. [PMID: 26646943 PMCID: PMC4672576 DOI: 10.1186/s12936-015-1008-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 11/21/2015] [Indexed: 11/16/2022] Open
Abstract
Background Malaria is still one of the most prevalent infectious diseases in the world. Sequestration of infected erythrocytes (IEs) is the prime mediator of disease. Cytoadhesion of IEs is mediated by members of the highly diverse Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1). A restricted sub-set of var genes encoding for PfEMP1s possessing the domain cassettes DC8 and DC13 were found to bind to the endothelial protein C receptor (EPCR). These var genes were shown to be highly expressed by parasites from patients with severe malaria clinical outcomes compared to those from patients with uncomplicated symptoms. Methods In order to further study the molecular mechanisms underlying DC8/DC13 expressing IEs adhesion to EPCR, a method was developed to produce highly pure recombinant EPCR. The IT4 parasite strain was selected on either anti-IT4-VAR19 purified IgG, EPCR or human brain endothelial cell line and their var gene expression profiles as well as their binding phenotypes were compared. The N-terminal region of IT4-VAR19 comprising a full-length DC8 cassette as well as the single EPCR binding CIDRα1.1 domain were also produced, and their immune recognition (IgG) was assessed using plasma samples from Beninese children presenting acute mild malaria, severe malaria or cerebral malaria at the time of their admission to the clinic, and from convalescent-phase plasma collected 30 days after anti-malarial treatment. Results The multi-domain VAR19-NTS-DBLγ6 binds to EPCR with a greater affinity than the CIDRα1.1 domain alone and this study also demonstrates that VAR19-NTS-DBLγ6 binding to the EPCR-expressing endothelial cell line (HBEC5i) is more pronounced than that of the CIDRα1.1 domain alone. IT4-VAR19 represents the preferentially expressed-PfEMP1 when FCR3-IEs are selected based on their capability to bind EPCR. Notably, no significant difference in the levels of antibodies towards IT4-VAR19 antigens was observed within all clinical groups between plasma samples collected during the acute malaria phase compared to samples collected 30 days after anti-malaria treatment. Conclusions These data indicate that even being the preferentially selected IT4-EPCR-binding variant, the IT4-VAR19-DC8 region does not appear to be associated with the acquisition of antibodies during a single severe paediatric malaria episode in Benin. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-1008-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Sofia Nunes-Silva
- Inserm UMR_1134, Paris, France. .,Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France. .,Institut National de la Transfusion Sanguine, 6 rue Alexandre Cabanel, 75015, Paris, France. .,Laboratory of Excellence GR-Ex, Paris, France.
| | - Sébastien Dechavanne
- Inserm UMR_1134, Paris, France. .,Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France. .,Institut National de la Transfusion Sanguine, 6 rue Alexandre Cabanel, 75015, Paris, France. .,Laboratory of Excellence GR-Ex, Paris, France.
| | - Azizath Moussiliou
- Laboratory of Excellence GR-Ex, Paris, France. .,Institut de Recherche pour le développement, UMR_216, Mère et enfant face aux infections tropicales, Paris, France. .,Faculté de pharmacie, PRES Sorbonne Paris Cité, Paris, France.
| | - Natalia Pstrąg
- Inserm UMR_1134, Paris, France. .,Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France. .,Institut National de la Transfusion Sanguine, 6 rue Alexandre Cabanel, 75015, Paris, France. .,Laboratory of Excellence GR-Ex, Paris, France.
| | - Jean-Philippe Semblat
- Inserm UMR_1134, Paris, France. .,Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France. .,Institut National de la Transfusion Sanguine, 6 rue Alexandre Cabanel, 75015, Paris, France. .,Laboratory of Excellence GR-Ex, Paris, France.
| | - Stéphane Gangnard
- Inserm UMR_1134, Paris, France. .,Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France. .,Institut National de la Transfusion Sanguine, 6 rue Alexandre Cabanel, 75015, Paris, France. .,Laboratory of Excellence GR-Ex, Paris, France.
| | - Nicaise Tuikue-Ndam
- Laboratory of Excellence GR-Ex, Paris, France. .,Institut de Recherche pour le développement, UMR_216, Mère et enfant face aux infections tropicales, Paris, France. .,Faculté de pharmacie, PRES Sorbonne Paris Cité, Paris, France.
| | - Philippe Deloron
- Laboratory of Excellence GR-Ex, Paris, France. .,Institut de Recherche pour le développement, UMR_216, Mère et enfant face aux infections tropicales, Paris, France. .,Faculté de pharmacie, PRES Sorbonne Paris Cité, Paris, France.
| | - Arnaud Chêne
- Inserm UMR_1134, Paris, France. .,Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France. .,Institut National de la Transfusion Sanguine, 6 rue Alexandre Cabanel, 75015, Paris, France. .,Laboratory of Excellence GR-Ex, Paris, France.
| | - Benoît Gamain
- Inserm UMR_1134, Paris, France. .,Université Paris Diderot, Sorbonne Paris Cité, UMR_S1134, Paris, France. .,Institut National de la Transfusion Sanguine, 6 rue Alexandre Cabanel, 75015, Paris, France. .,Laboratory of Excellence GR-Ex, Paris, France.
| |
Collapse
|
21
|
Babakhanyan A, Fang R, Wey A, Salanti A, Sama G, Efundem C, Leke RJI, Chen JJ, Leke RGF, Taylor DW. Comparison of the specificity of antibodies to VAR2CSA in Cameroonian multigravidae with and without placental malaria: a retrospective case-control study. Malar J 2015; 14:480. [PMID: 26626275 PMCID: PMC4666123 DOI: 10.1186/s12936-015-1023-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 11/26/2015] [Indexed: 11/10/2022] Open
Abstract
Background Antibodies (Ab) to VAR2CSA prevent Plasmodium falciparum-infected erythrocytes from sequestrating in the placenta, i.e., prevent placental malaria (PM). The specificity of Ab to VAR2CSA associated with absence of PM is unknown. Accordingly, differences in the specificity of Ab to VAR2CSA were compared between multigravidae with and without PM who had Ab to VAR2CSA. Methods In a retrospective case–control study, plasma collected from Cameroonian multigravidae with (n = 96) and without (n = 324) PM were screened in 21 assays that measured antibody levels to full length VAR2CSA (FV2), individual VAR2CSA DBL domains, VAR2CSA domains from different genetic backgrounds (variants), as well as proportion of high avidity Ab to FV2. Results Multigravidae with and without PM had similar levels of Ab to FV2, the six VAR2CSA DBL domains and different variants, while the proportion of high avidity Ab to FV2 was significantly higher in women without PM at delivery (p = 0.0030) compared to women with PM. In a logistic regression model adjusted for gravidity and age, the percentage of high avidity Ab to FV2 was associated with reduced likelihood of PM in multigravidae. A 5 % increase in proportion of high avidity Ab to FV2 was associated with a nearly 15 % lower likelihood of PM. Conclusion Ab avidity to FV2 may be an important indicator of immunity to PM. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-1023-6) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Anna Babakhanyan
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street, BSB 320, Honolulu, HI, 96813, USA.
| | - Rui Fang
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street, BSB 320, Honolulu, HI, 96813, USA.
| | - Andrew Wey
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street, BSB 320, Honolulu, HI, 96813, USA.
| | - Ali Salanti
- Department of Immunology and Microbiology, Centre for Medical Parasitology, University of Copenhagen, Copenhagen, Denmark.
| | - Grace Sama
- Faculty of Medicine and Biomedical Research, Biotechnology Centre, University of Yaounde 1, Yaounde, Cameroon.
| | - Canisia Efundem
- Faculty of Medicine and Biomedical Research, Biotechnology Centre, University of Yaounde 1, Yaounde, Cameroon.
| | - Robert J I Leke
- Faculty of Medicine and Biomedical Research, Biotechnology Centre, University of Yaounde 1, Yaounde, Cameroon.
| | - John J Chen
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street, BSB 320, Honolulu, HI, 96813, USA.
| | - Rose G F Leke
- Faculty of Medicine and Biomedical Research, Biotechnology Centre, University of Yaounde 1, Yaounde, Cameroon.
| | - Diane W Taylor
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street, BSB 320, Honolulu, HI, 96813, USA.
| |
Collapse
|