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Duffy PE, Gorres JP, Healy SA, Fried M. Malaria vaccines: a new era of prevention and control. Nat Rev Microbiol 2024:10.1038/s41579-024-01065-7. [PMID: 39025972 DOI: 10.1038/s41579-024-01065-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2024] [Indexed: 07/20/2024]
Abstract
Malaria killed over 600,000 people in 2022, a death toll that has not improved since 2015. Additionally, parasites and mosquitoes resistant to existing interventions are spreading across Africa and other regions. Vaccines offer hope to reduce the mortality burden: the first licensed malaria vaccines, RTS,S and R21, will be widely deployed in 2024 and should substantially reduce childhood deaths. In this Review, we provide an overview of the malaria problem and the Plasmodium parasite, then describe the RTS,S and R21 vaccines (the first vaccines for any human parasitic disease), summarizing their benefits and limitations. We explore next-generation vaccines designed using new knowledge of malaria pathogenesis and protective immunity, which incorporate antigens and platforms to elicit effective immune responses against different parasite stages in human or mosquito hosts. We describe a decision-making process that prioritizes malaria vaccine candidates for development in a resource-constrained environment. Future vaccines might improve upon the protective efficacy of RTS,S or R21 for children, or address the wider malaria scourge by preventing pregnancy malaria, reducing the burden of Plasmodium vivax or accelerating malaria elimination.
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Affiliation(s)
- Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA.
| | - J Patrick Gorres
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Sara A Healy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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2
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Gbaguidi MLE, Adamou R, Edslev S, Hansen A, Domingo ND, Dechavanne C, Massougbodji A, Garcia A, Theisen M, Milet J, Donadi EA, Courtin D. IgG and IgM responses to the Plasmodium falciparum asexual stage antigens reflect respectively protection against malaria during pregnancy and infanthood. Malar J 2024; 23:154. [PMID: 38764069 PMCID: PMC11103834 DOI: 10.1186/s12936-024-04970-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 04/29/2024] [Indexed: 05/21/2024] Open
Abstract
BACKGROUND Plasmodium falciparum malaria is a public health issue mostly seen in tropical countries. Until now, there is no effective malaria vaccine against antigens specific to the blood-stage of P. falciparum infection. Because the pathogenesis of malarial disease results from blood-stage infection, it is essential to identify the most promising blood-stage vaccine candidate antigens under natural exposure to malaria infection. METHODS A cohort of 400 pregnant women and their infants was implemented in South Benin. An active and passive protocol of malaria surveillance was established during pregnancy and infancy to precisely ascertain malaria infections during the follow-up. Twenty-eight antibody (Ab) responses specific to seven malaria candidate vaccine antigens were repeatedly quantified during pregnancy (3 time points) and infancy (6 time points) in order to study the Ab kinetics and their protective role. Abs were quantified by ELISA and logistic, linear and cox-proportional hazard model were performed to analyse the associations between Ab responses and protection against malaria in mothers and infants, taking into account socio-economic factors and for infants an environmental risk of exposure. RESULTS The levels of IgM against MSP1, MSP2 and MSP3 showed an early protective response against the onset of symptomatic malaria infections starting from the 18th month of life, whereas no association was found for IgG responses during infancy. In women, some IgG responses tend to be associated with a protection against malaria risk along pregnancy and at delivery, among them IgG3 against GLURP-R0 and IgG2 against MSP1. CONCLUSION The main finding suggests that IgM should be considered in vaccine designs during infanthood. Investigation of the functional role played by IgM in malaria protection needs further attention.
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Affiliation(s)
- Mahugnon L Erasme Gbaguidi
- Division of Clinical Immunology, Department of Medicine, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
- IRD, MERIT, Université Paris Cité, 75006, Paris, France
- Centre d'Etude Et de Recherche Sur Les Pathologies Associées À La Grossesse Et À L'Enfance, Cotonou, Bénin
| | - Rafiou Adamou
- IRD, MERIT, Université Paris Cité, 75006, Paris, France
- Centre d'Etude Et de Recherche Sur Les Pathologies Associées À La Grossesse Et À L'Enfance, Cotonou, Bénin
| | - Sofie Edslev
- Institut de Recherche Clinique du Bénin, Abomey-Calavi, Benin
| | - Anita Hansen
- Institut de Recherche Clinique du Bénin, Abomey-Calavi, Benin
| | - Nadia D Domingo
- Centre d'Etude Et de Recherche Sur Les Pathologies Associées À La Grossesse Et À L'Enfance, Cotonou, Bénin
| | | | | | - André Garcia
- IRD, MERIT, Université Paris Cité, 75006, Paris, France
| | - Michael Theisen
- Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Rigshospitalet, Copenhagen, Denmark
- Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark
- Department for Congenital Disorders, Statens Serum Institut, Copenhagen, Denmark
| | | | - Eduardo A Donadi
- Division of Clinical Immunology, Department of Medicine, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil
| | - David Courtin
- IRD, MERIT, Université Paris Cité, 75006, Paris, France.
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Frempong NA, Mama A, Adu B, Kusi KA, Ofori MF, Ahiabor C, Anyan WK, Debrah AY, Anang AA, Ndam NT, Courtin D. Antibody response to malaria vaccine candidates in pregnant women with Plasmodium falciparum and Schistosoma haematobium infections. Parasite Immunol 2024; 46:e13027. [PMID: 38587985 DOI: 10.1111/pim.13027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 12/21/2023] [Accepted: 01/22/2024] [Indexed: 04/10/2024]
Abstract
Malaria in pregnancy has severe consequences for the mother and foetus. Antibody response to specific malaria vaccine candidates (MVC) has been associated with a decreased risk of clinical malaria and its outcomes. We studied Plasmodium falciparum (Pf) and Schistosoma haematobium (Sh) infections and factors that could influence antibody responses to MVC in pregnant women. A total of 337 pregnant women receiving antenatal care (ANC) and 139 for delivery participated in this study. Pf infection was detected by qPCR and Sh infection using urine filtration method. Antibody levels against CSP, AMA-1, GLURP-R0, VAR2CSA and Pfs48/45 MVC were quantified by ELISA. Multivariable linear regression models identified factors associated with the modulation of antibody responses. The prevalence of Pf and Sh infections was 27% and 4% at ANC and 7% and 4% at delivery. Pf infection, residing in Adidome and multigravidae were positively associated with specific IgG response to CSP, AMA-1, GLURP-R0 and VAR2CSA. ITN use and IPTp were negatively associated with specific IgG response to GLURP-R0 and Pfs48/45. There was no association between Sh infection and antibody response to MVC at ANC or delivery. Pf infections in pregnant women were positively associated with antibody response to CSP, GLURP-R0 and AMA-1. Antibody response to GLURP-R0 and Pfs48/45 was low for IPTp and ITN users. This could indicate a lower exposure to Pf infection and low malaria prevalence observed at delivery.
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Affiliation(s)
- Naa Adjeley Frempong
- Department of Clinical Microbiology, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
- Parasitology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Atikatou Mama
- Inserm U 1016, Institut Cochin, Université de, Paris, France
| | - Bright Adu
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Kwadwo Asamoah Kusi
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Michael F Ofori
- Immunology Department, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon, Ghana
| | - Charity Ahiabor
- Science Laboratory Department, Accra Technical University, Accra, Ghana
| | - William K Anyan
- Department of Clinical Microbiology, School of Medical Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Alex Yaw Debrah
- Faculty of Health Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Abraham A Anang
- Institute for Environment and Sanitation Studies (IESS), University of Ghana, Legon, Ghana
| | - Nicaise T Ndam
- UMR 216 MERIT, IRD, Université Paris Cité, Paris, France
| | - David Courtin
- UMR 216 MERIT, IRD, Université Paris Cité, Paris, France
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4
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Ma R, Salinas ND, Orr-Gonzalez S, Richardson B, Ouahes T, Torano H, Jenkins BJ, Dickey TH, Neal J, Duan J, Morrison RD, Gittis AG, Doritchamou JYA, Zaidi I, Lambert LE, Duffy PE, Tolia NH. Structure-guided design of VAR2CSA-based immunogens and a cocktail strategy for a placental malaria vaccine. PLoS Pathog 2024; 20:e1011879. [PMID: 38437239 PMCID: PMC10939253 DOI: 10.1371/journal.ppat.1011879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 03/14/2024] [Accepted: 11/29/2023] [Indexed: 03/06/2024] Open
Abstract
Placental accumulation of Plasmodium falciparum infected erythrocytes results in maternal anemia, low birth weight, and pregnancy loss. The parasite protein VAR2CSA facilitates the accumulation of infected erythrocytes in the placenta through interaction with the host receptor chondroitin sulfate A (CSA). Antibodies that prevent the VAR2CSA-CSA interaction correlate with protection from placental malaria, and VAR2CSA is a high-priority placental malaria vaccine antigen. Here, structure-guided design leveraging the full-length structures of VAR2CSA produced a stable immunogen that retains the critical conserved functional elements of VAR2CSA. The design expressed with a six-fold greater yield than the full-length protein and elicited antibodies that prevent adhesion of infected erythrocytes to CSA. The reduced size and adaptability of the designed immunogen enable efficient production of multiple variants of VAR2CSA for use in a cocktail vaccination strategy to increase the breadth of protection. These designs form strong foundations for the development of potent broadly protective placental malaria vaccines.
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Affiliation(s)
- Rui Ma
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Nichole D Salinas
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sachy Orr-Gonzalez
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Brandi Richardson
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Tarik Ouahes
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Holly Torano
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Bethany J Jenkins
- Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Thayne H Dickey
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jillian Neal
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Junhui Duan
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Robert D Morrison
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Apostolos G Gittis
- Structural Biology Section, Research Technologies Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Justin Y A Doritchamou
- Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Irfan Zaidi
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Lynn E Lambert
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Patrick E Duffy
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Niraj H Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
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5
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Mahamar A, Traore M, Swihart B, Attaher O, Diarra BS, Santara G, Issiaka D, Barry A, Sidibé Y, Dicko YT, Keita S, Ndiaye O, Dicko A, Duffy PE, Fried M. Acquisition of antibodies that block Plasmodium falciparum adhesion to placental receptor chondroitin sulfate A with increasing gravidity in Malian women. Front Immunol 2024; 14:1330962. [PMID: 38274790 PMCID: PMC10808177 DOI: 10.3389/fimmu.2023.1330962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 12/20/2023] [Indexed: 01/27/2024] Open
Abstract
In malaria-endemic areas, pregnant women are more susceptible to Plasmodium falciparum infection, especially primigravidae. During pregnancy, parasites sequester in the placenta and bind to the receptor chondroitin sulfate (CSA). This unique adhesion is mediated by the parasite protein VAR2CSA expressed on the surface of infected erythrocytes (IE). Placental malaria is associated with poor pregnancy outcomes including perinatal mortality, preterm delivery, small for gestational age (SGA) and low birthweight deliveries. Over successive pregnancies, women acquire functional antibodies that inhibit IE adhesion to CSA. Here, we examine the development of anti-adhesion activity and the breadth of anti-adhesion activity as a function of number of previous pregnancies, using samples collected from pregnant women living in an area with high seasonal malaria transmission. Women reached plateau levels of anti-adhesion activity and breadth of anti-adhesion activity after 5 pregnancies. We related the level of anti-adhesion activity and reactivity with surface IE to SGA 19/232 pregnancies resulted in SGA, and report that an increase of 10% in median anti-adhesion activity reduced the odds of SGA by 13% and this relationship approached significance. Further, at an anti-adhesion activity level of 43.7%, an increase of 10% in the breadth of activity significantly reduced the odds of SGA by 21.5%. Antibodies that recognize IE surface increased over successive pregnancies, but were not associated with a reduction in SGA. These results can serve as a guideline for assessing vaccine candidates aiming to reduce poor pregnancy outcomes associated with placental malaria.
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Affiliation(s)
- Almahamoudou Mahamar
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Moussa Traore
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Bruce Swihart
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, United States
| | - Oumar Attaher
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Bacary Soumana Diarra
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Gaoussou Santara
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Djibrilla Issiaka
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Amadou Barry
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Youssoufa Sidibé
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Yahia T. Dicko
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Sekouba Keita
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Oulematou Ndiaye
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Alassane Dicko
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, Bamako, Mali
| | - Patrick E. Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, United States
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, United States
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6
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Roessner R, Michelarakis N, Gräter F, Aponte-Santamaría C. Mechanical forces control the valency of the malaria adhesin VAR2CSA by exposing cryptic glycan binding sites. PLoS Comput Biol 2023; 19:e1011726. [PMID: 38117828 PMCID: PMC10786402 DOI: 10.1371/journal.pcbi.1011726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 01/12/2024] [Accepted: 12/02/2023] [Indexed: 12/22/2023] Open
Abstract
Plasmodium falciparum (Pf) is responsible for the most lethal form of malaria. VAR2CSA is an adhesin protein expressed by this parasite at the membrane of infected erythrocytes for attachment to the placenta, leading to pregnancy-associated malaria. VAR2CSA is a large 355 kDa multidomain protein composed of nine extracellular domains, a transmembrane helix, and an intracellular domain. VAR2CSA binds to Chondroitin Sulphate A (CSA) of the proteoglycan matrix of the placenta. Shear flow, as the one occurring in blood, has been shown to enhance the (VAR2CSA-mediated) adhesion of Pf-infected erythrocytes on the CSA-matrix. However, the underlying molecular mechanism governing this enhancement has remained elusive. Here, we address this question by using equilibrium, force-probe, and docking-based molecular dynamics simulations. We subjected the VAR2CSA protein-CSA sugar complex to a force mimicking the tensile force exerted on this system due to the shear of the flowing blood. We show that upon this force exertion, VAR2CSA undergoes a large opening conformational transition before the CSA sugar chain dissociates from its main binding site. This preferential order of events is caused by the orientation of the molecule during elongation, as well as the strong electrostatic attraction of the sugar to the main protein binding site. Upon opening, two additional cryptic CSA binding sites get exposed and a functional dodecameric CSA molecule can be stably accommodated at these force-exposed positions. Thus, our results suggest that mechanical forces increase the avidity of VAR2CSA by turning it from a monovalent to a multivalent state. We propose this to be the molecular cause of the observed shear-enhanced adherence. Mechanical control of the valency of VAR2CSA is an intriguing hypothesis that can be tested experimentally and which is of relevance for the understanding of the malaria infection and for the development of anti placental-malaria vaccines targeting VAR2CSA.
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Affiliation(s)
- Rita Roessner
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Nicholas Michelarakis
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Frauke Gräter
- Molecular Biomechanics Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
- Interdisciplinary Center for Scientific Computing, Heidelberg University, Heidelberg, Germany
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7
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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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8
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Kassa MW, Hasang W, Barateiro A, Damelang T, Brewster J, Dombrowski JG, Longley RJ, Chung AW, Wunderlich G, Mueller I, Aitken EH, Marinho CRF, Rogerson SJ. Acquisition of antibodies to Plasmodium falciparum and Plasmodium vivax antigens in pregnant women living in a low malaria transmission area of Brazil. Malar J 2022; 21:360. [PMID: 36457056 PMCID: PMC9714246 DOI: 10.1186/s12936-022-04402-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 11/25/2022] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Pregnant women have increased susceptibility to Plasmodium falciparum malaria and acquire protective antibodies over successive pregnancies. Most studies that investigated malaria antibody responses in pregnant women are from high transmission areas in sub-Saharan Africa, while reports from Latin America are scarce and inconsistent. The present study sought to explore the development of antibodies against P. falciparum and Plasmodium vivax antigens in pregnant women living in a low transmission area in the Brazilian Amazon. METHODS In a prospective cohort study, plasma samples from 408 pregnant women (of whom 111 were infected with P. falciparum, 96 had infections with P. falciparum and P. vivax, and 201 had no Plasmodium infection) were used to measure antibody levels. Levels of IgG and opsonizing antibody to pregnancy-specific variant surface antigens (VSAs) on infected erythrocytes (IEs), 10 recombinant VAR2CSA Duffy binding like (DBL domains), 10 non-pregnancy-specific P. falciparum merozoite antigens, and 10 P. vivax antigens were measured by flow cytometry, ELISA, and multiplex assays. Antibody levels and seropositivity among the groups were compared. RESULTS Antibodies to VSAs on P. falciparum IEs were generally low but were higher in currently infected women and women with multiple P. falciparum episodes over pregnancy. Many women (21%-69%) had antibodies against each individual VAR2CSA DBL domain, and antibodies to DBLs correlated with each other (r ≥ 0.55, p < 0.0001), but not with antibody to VSA or history of infection. Infection with either malaria species was associated with higher seropositivity rate for antibodies against P. vivax proteins, adjusted odds ratios (95% CI) ranged from 5.6 (3.2, 9.7), p < 0.0001 for PVDBPII-Sal1 to 15.7 (8.3, 29.7), p < 0.0001 for PvTRAg_2. CONCLUSIONS Pregnant Brazilian women had low levels of antibodies to pregnancy-specific VSAs that increased with exposure. They frequently recognized both VAR2CSA DBL domains and P. vivax antigens, but only the latter varied with infection. Apparent antibody prevalence is highly dependent on the assay platform used.
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Affiliation(s)
- Meseret W. Kassa
- grid.1008.90000 0001 2179 088XDepartment of Medicine, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Level 5, 792 Elizabeth St, University of Melbourne, Melbourne, VIC 3000 Australia
| | - Wina Hasang
- grid.1008.90000 0001 2179 088XDepartment of Infectious Diseases, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC Australia
| | - André Barateiro
- grid.11899.380000 0004 1937 0722Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Timon Damelang
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, University of Melbourne, Melbourne, VIC Australia
| | - Jessica Brewster
- grid.1042.70000 0004 0432 4889Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC Australia
| | - Jamille G. Dombrowski
- grid.11899.380000 0004 1937 0722Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Rhea J. Longley
- grid.1042.70000 0004 0432 4889Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Medical Biology, University of Melbourne, Melbourne, VIC Australia
| | - Amy W. Chung
- grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, University of Melbourne, Melbourne, VIC Australia
| | - Gerhard Wunderlich
- grid.11899.380000 0004 1937 0722Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Ivo Mueller
- grid.1042.70000 0004 0432 4889Population Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Medical Biology, University of Melbourne, Melbourne, VIC Australia
| | - Elizabeth H. Aitken
- grid.1008.90000 0001 2179 088XDepartment of Infectious Diseases, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, University of Melbourne, Melbourne, VIC Australia
| | - Claudio R. F. Marinho
- grid.11899.380000 0004 1937 0722Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Stephen J. Rogerson
- grid.1008.90000 0001 2179 088XDepartment of Medicine, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Level 5, 792 Elizabeth St, University of Melbourne, Melbourne, VIC 3000 Australia ,grid.1008.90000 0001 2179 088XDepartment of Infectious Diseases, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC Australia
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9
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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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10
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Rotich AK, Takashima E, Yanow SK, Gitaka J, Kanoi BN. Towards identification and development of alternative vaccines against pregnancy-associated malaria based on naturally acquired immunity. FRONTIERS IN TROPICAL DISEASES 2022. [DOI: 10.3389/fitd.2022.988284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Pregnant women are particularly susceptible to Plasmodium falciparum malaria, leading to substantial maternal and infant morbidity and mortality. While highly effective malaria vaccines are considered an essential component towards malaria elimination, strides towards development of vaccines for pregnant women have been minimal. The leading malaria vaccine, RTS,S/AS01, has modest efficacy in children suggesting that it needs to be strengthened and optimized if it is to be beneficial for pregnant women. Clinical trials against pregnancy-associated malaria (PAM) focused on the classical VAR2CSA antigen are ongoing. However, additional antigens have not been identified to supplement these initiatives despite the new evidence that VAR2CSA is not the only molecule involved in pregnancy-associated naturally acquired immunity. This is mainly due to a lack of understanding of the immune complexities in pregnancy coupled with difficulties associated with expression of malaria recombinant proteins, low antigen immunogenicity in humans, and the anticipated complications in conducting and implementing a vaccine to protect pregnant women. With the accelerated evolution of molecular technologies catapulted by the global pandemic, identification of novel alternative vaccine antigens is timely and feasible. In this review, we discuss approaches towards novel antigen discovery to support PAM vaccine studies.
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11
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The impact of human complement on the clinical outcome of malaria infection. Mol Immunol 2022; 151:19-28. [PMID: 36063583 DOI: 10.1016/j.molimm.2022.08.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 08/19/2022] [Accepted: 08/25/2022] [Indexed: 11/21/2022]
Abstract
The tropical disease malaria remains a major cause of global morbidity. Once transmitted to the human by a blood-feeding mosquito, the unicellular malaria parasite comes into contact with the complement system and continues to interact with human complement during its intraerythrocytic replication cycles. In the course of infection, both the classical and the alternative pathway of complement are activated, leading to parasite opsonization and lysis as well as the induction of complement-binding antibodies. While complement activity can be linked to the severity of malaria, it remains to date unclear, whether human complement is beneficial for protective immunity or if extensive complement reactions may rather enhance pathogenesis. In addition, the parasite has evolved molecular strategies to circumvent attack by human complement and has even developed means to utilize complement factors as mediators of host cell infection. In this review, we highlight current knowledge on the role of human complement for the progression of malaria infection. We discuss the various types of interactions between malaria parasites and complement factors with regard to immunity and infection outcome and set a special emphasis on the dual role of complement in the context of parasite fitness.
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12
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Unger HW, Bleicher A, Ome-Kaius M, Aitken EH, Rogerson SJ. Associations of maternal iron deficiency with malaria infection in a cohort of pregnant Papua New Guinean women. Malar J 2022; 21:153. [PMID: 35619134 PMCID: PMC9137066 DOI: 10.1186/s12936-022-04177-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 05/07/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Iron deficiency (ID) is common in malaria-endemic settings. Intermittent preventative treatment of malaria in pregnancy (IPTp) and iron supplementation are core components of antenatal care in endemic regions to prevent adverse pregnancy outcomes. ID has been associated with reduced risk of malaria infection, and correspondingly, iron supplementation with increased risk of malaria infection, in some studies. METHODS A secondary analysis was conducted amongst 1888 pregnant women enrolled in a malaria prevention trial in Papua New Guinea. Maternal ID was defined as inflammation-corrected plasma ferritin levels < 15 μg/L at antenatal enrolment. Malaria burden (Plasmodium falciparum, Plasmodium vivax) was determined by light microscopy, polymerase chain reaction, and placental histology. Multiple logistic and linear regression analyses explored the relationship of ID or ferritin levels with indicators of malaria infection. Models were fitted with interaction terms to assess for modification of iron-malaria relationships by gravidity or treatment arm. RESULTS Two-thirds (n = 1226) and 13.7% (n = 258) of women had ID and peripheral parasitaemia, respectively, at antenatal enrolment (median gestational age: 22 weeks), and 18.7% (120/1,356) had evidence of malaria infection on placental histology. Overall, ID was associated with reduced odds of peripheral parasitaemia at enrolment (adjusted odds ratio [aOR] 0.50; 95% confidence interval [95% CI] 0.38, 0.66, P < 0.001); peripheral parasitaemia at delivery (aOR 0.68, 95% CI 0.46, 1.00; P = 0.050); and past placental infection (aOR 0.35, 95% CI 0.24, 0.50; P < 0.001). Corresponding increases in the odds of infection were observed with two-fold increases in ferritin levels. There was effect modification of iron-malaria relationships by gravidity. At delivery, ID was associated with reduced odds of peripheral parasitaemia amongst primigravid (AOR 0.44, 95% CI 0.25, 0.76; P = 0.003), but not multigravid women (AOR 1.12, 95% CI 0.61, 2.05; P = 0.720). A two-fold increase in ferritin associated with increased odds of placental blood infection (1.44, 95% CI 1.06, 1.96; P = 0.019) and active placental infection on histology amongst primigravid women only (1.24, 95% CI 1.00, 1.54; P = 0.052). CONCLUSIONS Low maternal ferritin at first antenatal visit was associated with a lower risk of malaria infection during pregnancy, most notably in primigravid women. The mechanisms by which maternal iron stores influence susceptibility to infection with Plasmodium species require further investigation. TRIAL REGISTRATION
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Affiliation(s)
- Holger W Unger
- Department of Obstetrics and Gynaecology, Royal Darwin Hospital, Darwin, NT, Australia
- Menzies School of Health Research, Charles Darwin University, Darwin, NT, Australia
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK
| | - Andie Bleicher
- Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia
| | - Maria Ome-Kaius
- Papua New Guinea Institute of Medical Research, Goroka, Papua New Guinea
| | - Elizabeth H Aitken
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia
| | - Stephen J Rogerson
- Department of Medicine (RMH), Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia.
- Department of Infectious Diseases, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Melbourne, VIC, Australia.
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13
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Doritchamou JY, Renn JP, Jenkins B, Fried M, Duffy PE. A single full-length VAR2CSA ectodomain variant purifies broadly neutralizing antibodies against placental malaria isolates. eLife 2022; 11:76264. [PMID: 35103596 PMCID: PMC8959597 DOI: 10.7554/elife.76264] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
Placental malaria (PM) is a deadly syndrome most frequent and severe in first pregnancies. PM results from accumulation of Plasmodium falciparum-infected erythrocytes (IE) that express the surface antigen VAR2CSA and bind to chondroitin sulfate A (CSA) in the placenta. Women become PM-resistant over successive pregnancies as they develop anti-adhesion and anti-VAR2CSA antibodies, supporting VAR2CSA as the leading PM-vaccine candidate. However, the first VAR2CSA subunit vaccines failed to induce broadly neutralizing antibody and it is known that naturally acquired antibodies target both variant-specific and conserved epitopes. It is crucial to determine whether effective vaccines will require incorporation of many or only a single VAR2CSA variants. Here, IgG from multigravidae was sequentially purified on five full-length VAR2CSA ectodomain variants, thereby depleting IgG reactivity to each. The five VAR2CSA variants purified ~0.7% of total IgG and yielded both strain-transcending and strain-specific reactivity to VAR2CSA and IE-surface antigen. In two independent antibody purification/depletion experiments with permutated order of VAR2CSA variants, IgG purified on the first VAR2CSA antigen displayed broad cross-reactivity to both recombinant and native VAR2CSA variants, and inhibited binding of all isolates to CSA. IgG remaining after depletion on all variants showed significantly reduced binding-inhibition activity compared to initial total IgG. These findings demonstrate that a single VAR2CSA ectodomain variant displays conserved epitopes that are targeted by neutralizing (or binding-inhibitory) antibodies shared by multiple parasite strains, including maternal isolates. This suggests that a broadly effective PM-vaccine can be achieved with a limited number of VAR2CSA variants. Contracting malaria during pregnancy – especially a first pregnancy – can lead to a severe, placental form of the disease that is often fatal. Red blood cells infected with the malaria parasite Plasmodium falciparum display a protein, VAR2CSA, which can recognize and bind CSA molecules present on placental cells and in placental blood spaces. This leads to the infected blood cells accumulating in the placenta and inducing harmful inflammation. Having been exposed to the parasite in prior pregnancies generates antibodies that target VAR2CSA, stopping the infected blood cells from latching onto placental CSA or tagging them for immune destruction. Overall, this makes placental malaria less severe in following pregnancies, and suggests that vaccines could be developed based on VAR2CSA. However, this protein has regions that can vary in structure, meaning that P. falciparaum can generate many VAR2CSA variants. Individuals exposed to the parasite naturally generate antibodies that block a wide array of variants from attaching to CSA. In contrast, first-generation vaccines based on VAR2CSA fragments have only induced variant-specific antibodies, therefore offering limited protection against infection. As a response, Doritchamou et al. set out to find VAR2CSA structures that could be recognized by antibodies targeting an array of variants. Blood was obtained from women who had had multiple pregnancies and were immune to malaria. Their plasma was passed over five different large VAR2CSA variants in order to isolate and purify antibodies that attached to these structures. Doritchamou et al. found that antibodies binding to individual VAR2CSA structures could also recognise a wide array of VAR2CSA variants and blocked all tested parasites from sticking to CSA. While further research is needed, these findings highlight antibodies that cross-react to diverse VAR2CSA variants and could be used to design more effective vaccines targeting placental malaria.
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Affiliation(s)
- Justin Ya Doritchamou
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, United States
| | - Jonathan P Renn
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, United States
| | - Bethany Jenkins
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, United States
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, Rockville, United States
| | - Patrick E Duffy
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, Bethesda, United States
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14
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Retrospective study of toxoplasmosis prevalence in pregnant women in Benin and its relation with malaria. PLoS One 2022; 17:e0262018. [PMID: 34995295 PMCID: PMC8741053 DOI: 10.1371/journal.pone.0262018] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 12/15/2021] [Indexed: 11/19/2022] Open
Abstract
Background
Globally distributed with variable prevalence depending on geography, toxoplasmosis is a zoonosis caused by an obligate intracellular protozoan parasite, Toxoplasma gondii. This disease is usually benign but poses a risk for immunocompromised people and for newborns of mothers with a primary infection during pregnancy because of the risk of congenital toxoplasmosis (CT). CT can cause severe damage to fetuses-newborns. To our knowledge, no study has been conducted in sub-Saharan Africa on toxoplasmosis seroprevalence, seroconversion and CT in a large longitudinal cohort and furthermore, no observation has been made of potential relationships with malaria.
Methods
We performed a retrospective toxoplasmosis serological study using available samples from a large cohort of 1,037 pregnant women who were enrolled in a malaria follow-up during the 2008–2010 period in a rural area in Benin. We also used some existing data to investigate potential relationships between the maternal toxoplasmosis serological status and recorded malaria infections.
Results
Toxoplasmosis seroprevalence, seroconversion and CT rates were 52.6%, 3.4% and 0.2%, respectively, reflecting the population situation of toxoplasmosis, without targeted medical intervention. The education level influences the toxoplasmosis serological status of women, with women with little or no formal education have greater immunity than others. Surprisingly, toxoplasmosis seropositive pregnant women tended to present lower malaria infection during pregnancy (number) or at delivery (presence) and to have lower IgG levels to Plasmodium falciparum Apical Membrane Antigen 1, compared to toxoplasmosis seronegative women.
Conclusions
The high toxoplasmosis seroprevalence indicates that prevention against this parasite remains important to deploy and must be accessible and understandable to and for all individuals (educated and non-educated). A potential protective role against malaria conferred by a preexisting toxoplasmosis infection needs to be explored more precisely to examine the environmental, parasitic and/or immune aspects.
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15
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Kassa MW, Hasang W, Rogerson SJ. Antibody-Dependent THP-1 Cell-Mediated Phagocytosis of Plasmodium falciparum-Infected Erythrocytes. Methods Mol Biol 2022; 2470:617-628. [PMID: 35881378 DOI: 10.1007/978-1-0716-2189-9_46] [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
Antibodies that recognize variant surface antigens (VSAs) expressed on Plasmodium falciparum-infected erythrocytes (IEs) opsonize IEs for phagocytic clearance. The anti-VSA antibodies promote antibody-dependent cellular phagocytosis (ADCP) of IEs by interacting with innate immune cells. ADCP is an important immune effector mechanism of parasite clearance. ADCP can be a tool to assess the efficacy of vaccine-induced antibodies, in addition to measuring the neutralizing ability of antibodies. Here, we developed and validated an efficient and high-throughput plate-based flow cytometric assay to measure ADCP of IEs using the human monocytic THP-1 cell line. This flow cytometric assay can be used to analyze the level of naturally acquired or vaccine-induced opsonic antibodies in large cohorts.
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Affiliation(s)
- Meseret Workineh Kassa
- Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Wina Hasang
- Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Stephen John Rogerson
- Department of Medicine, The Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia.
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16
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Renn JP, Doritchamou JYA, Duffy PE. Expression of Large Full-Length PfEMP1 Proteins in HEK293 Cells. Methods Mol Biol 2022; 2470:283-298. [PMID: 35881353 DOI: 10.1007/978-1-0716-2189-9_21] [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
Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1) is a family of proteins expressed on the surface of red blood cells infected by Plasmodium falciparum. PfEMP1 proteins play a vital role in parasite virulence, and thus are important vaccine candidates to prevent severe disease. VAR2CSA is one specific PfEMP1 essential for pregnancy malaria pathogenesis, and the primary target in pregnancy malaria vaccine development. However, similar to other PfEMP1 proteins, expression of recombinant full-length VAR2CSA is difficult due to its large size, multidomain architecture and high cysteine content. To date, there has been success using higher ordered expression systems (such as mammalian and insect cells) to generate folded and active VAR2CSA. However, recent improvements with mammalian expression systems including cell lines and promoters have pushed the boundaries of yields. Here, we describe a modified protocol beyond current systems that enhances yields of full-length VAR2CSA and can generate higher quantities of material for protein structural and functional characterization.
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Affiliation(s)
- Jonathan Paul Renn
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Justin Yai Alamou Doritchamou
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Patrick Emmet 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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17
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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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18
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Renn JP, Doritchamou JYA, Tentokam BCN, Morrison RD, Cowles MV, Burkhardt M, Ma R, Tolia NH, Fried M, Duffy PE. Allelic variants of full-length VAR2CSA, the placental malaria vaccine candidate, differ in antigenicity and receptor binding affinity. Commun Biol 2021; 4:1309. [PMID: 34799664 PMCID: PMC8604988 DOI: 10.1038/s42003-021-02787-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/14/2021] [Indexed: 11/16/2022] Open
Abstract
Plasmodium falciparum-infected erythrocytes (IE) sequester in the placenta via surface protein VAR2CSA, which binds chondroitin sulfate A (CSA) expressed on the syncytiotrophoblast surface, causing placental malaria (PM) and severe adverse outcomes in mothers and their offspring. VAR2CSA belongs to the PfEMP1 variant surface antigen family; PfEMP1 proteins mediate IE adhesion and facilitate parasite immunoevasion through antigenic variation. Here we produced deglycosylated (native-like) and glycosylated versions of seven recombinant full-length VAR2CSA ectodomains and compared them for antigenicity and adhesiveness. All VAR2CSA recombinants bound CSA with nanomolar affinity, and plasma from Malian pregnant women demonstrated antigen-specific reactivity that increased with gravidity and trimester. However, allelic and glycosylation variants differed in their affinity to CSA and their serum reactivities. Deglycosylated proteins (native-like) showed higher CSA affinity than glycosylated proteins for all variants except NF54. Further, the gravidity-related increase in serum VAR2CSA reactivity (correlates with acquisition of protective immunity) was absent with the deglycosylated form of atypical M200101 VAR2CSA with an extended C-terminal region. Our findings indicate significant inter-allelic differences in adhesion and seroreactivity that may contribute to the heterogeneity of clinical presentations, which could have implications for vaccine design. Full-length VAR2CSA is a potential placental malaria vaccine candidate and in this study, Renn et al. compare antigenicity and receptor binding affinity of different allelic variants in blood samples from pregnant women. Their data show that inter-allelic differences may contribute to the heterogeneity of clinical presentations, which could have implications for vaccine design.
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Affiliation(s)
- Jonathan P Renn
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Justin Y A Doritchamou
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Bergeline C Nguemwo Tentokam
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Robert D Morrison
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Matthew V Cowles
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Martin Burkhardt
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Rui Ma
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Niraj H Tolia
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - 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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19
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Chua CLL, Khoo SKM, Ong JLE, Ramireddi GK, Yeo TW, Teo A. Malaria in Pregnancy: From Placental Infection to Its Abnormal Development and Damage. Front Microbiol 2021; 12:777343. [PMID: 34867919 PMCID: PMC8636035 DOI: 10.3389/fmicb.2021.777343] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 10/20/2021] [Indexed: 11/24/2022] Open
Abstract
Malaria remains a global health burden with Plasmodium falciparum accounting for the highest mortality and morbidity. Malaria in pregnancy can lead to the development of placental malaria, where P. falciparum-infected erythrocytes adhere to placental receptors, triggering placental inflammation and subsequent damage, causing harm to both mother and her infant. Histopathological studies of P. falciparum-infected placentas revealed various placental abnormalities such as excessive perivillous fibrinoid deposits, breakdown of syncytiotrophoblast integrity, trophoblast basal lamina thickening, increased syncytial knotting, and accumulation of mononuclear immune cells within intervillous spaces. These events in turn, are likely to impair placental development and function, ultimately causing placental insufficiency, intrauterine growth restriction, preterm delivery and low birth weight. Hence, a better understanding of the mechanisms behind placental alterations and damage during placental malaria is needed for the design of effective interventions. In this review, using evidence from human studies and murine models, an integrated view on the potential mechanisms underlying placental pathologies in malaria in pregnancy is provided. The molecular, immunological and metabolic changes in infected placentas that reflect their responses to the parasitic infection and injury are discussed. Finally, potential models that can be used by researchers to improve our understanding on the pathogenesis of malaria in pregnancy and placental pathologies are presented.
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Affiliation(s)
| | | | - Jun Long Ernest Ong
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | | | - Tsin Wen Yeo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- National Center for Infectious Diseases, Singapore, Singapore
- Department of Infectious Diseases, Tan Tock Seng Hospital, Singapore, Singapore
| | - Andrew Teo
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
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20
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Keitany GJ, Jenkins BJ, Obiakor HT, Daniel S, Muehlenbachs A, Semblat JP, Gamain B, Doritchamou JYA, Desai SA, MacDonald NJ, Narum DL, Morrison R, Saveria T, Vignali M, Oleinikov AV, Fried M, Duffy PE. An invariant protein that co-localizes with VAR2CSA on Plasmodium falciparum-infected red cells binds to chondroitin sulfate A. J Infect Dis 2021; 225:2011-2022. [PMID: 34718641 DOI: 10.1093/infdis/jiab550] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 10/25/2021] [Indexed: 11/14/2022] Open
Abstract
Plasmodium falciparum-infected red blood cells (iRBCs) bind and sequester in deep vascular beds, causing malaria-related disease and death. In pregnant women, VAR2CSA binds to chondroitin sulfate A (CSA) and mediates placental sequestration, making it the major placental malaria (PM) vaccine target. Here, we characterize an invariant protein associated with PM called Plasmodium falciparum chondroitin sulfate A ligand (PfCSA-L). Recombinant PfCSA-L binds both placental CSA and VAR2CSA with nanomolar affinity, and is coexpressed on the iRBC surface with VAR2CSA. Unlike VAR2CSA, which is anchored by a transmembrane domain, PfCSA-L is peripherally associated with the outer surface of knobs through high affinity protein-protein interactions with VAR2CSA. This suggests iRBC sequestration involves complexes of invariant and variant surface proteins, allowing parasites to maintain both diversity and function at the iRBC surface. PfCSA-L is a promising target for intervention because it is well conserved, exposed on infected cells, and expressed and localized with VAR2CSA.
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Affiliation(s)
- Gladys J Keitany
- Center for Infectious Disease Research, Seattle, WA, USA.,University of Washington, Department of Pathobiology, Seattle, WA, USA
| | - Bethany J Jenkins
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD, USA
| | - Harold T Obiakor
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD, USA
| | - Shaji Daniel
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD, USA
| | - Atis Muehlenbachs
- University of Washington Medical Center, Anatomic Pathology, Seattle, WA, USA
| | - Jean-Philippe Semblat
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, Inserm, F-75015, Paris, France
| | - Benoit Gamain
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, Inserm, F-75015, Paris, France
| | | | - Sanjay A Desai
- Laboratory of Malaria and Vector Research, NIAID, NIH, Rockville, MD
| | | | - David L Narum
- Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD, USA
| | | | - Tracy Saveria
- Center for Infectious Disease Research, Seattle, WA, USA
| | | | | | - Michal Fried
- Center for Infectious Disease Research, Seattle, WA, USA.,University of Washington, Department of Pathobiology, Seattle, WA, USA.,Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD, USA
| | - Patrick E Duffy
- Center for Infectious Disease Research, Seattle, WA, USA.,University of Washington, Department of Pathobiology, Seattle, WA, USA.,Laboratory of Malaria Immunology and Vaccinology, NIAID, NIH, Bethesda, MD, USA
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21
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D'haeseleer P, Collette NM, Lao V, Segelke BW, Branda SS, Franco M. Shotgun Immunoproteomic Approach for the Discovery of Linear B-Cell Epitopes in Biothreat Agents Francisella tularensis and Burkholderia pseudomallei. Front Immunol 2021; 12:716676. [PMID: 34659206 PMCID: PMC8513525 DOI: 10.3389/fimmu.2021.716676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 09/02/2021] [Indexed: 11/13/2022] Open
Abstract
Peptide-based subunit vaccines are coming to the forefront of current vaccine approaches, with safety and cost-effective production among their top advantages. Peptide vaccine formulations consist of multiple synthetic linear epitopes that together trigger desired immune responses that can result in robust immune memory. The advantages of linear compared to conformational epitopes are their simple structure, ease of synthesis, and ability to stimulate immune responses by means that do not require complex 3D conformation. Prediction of linear epitopes through use of computational tools is fast and cost-effective, but typically of low accuracy, necessitating extensive experimentation to verify results. On the other hand, identification of linear epitopes through experimental screening has been an inefficient process that requires thorough characterization of previously identified full-length protein antigens, or laborious techniques involving genetic manipulation of organisms. In this study, we apply a newly developed generalizable screening method that enables efficient identification of B-cell epitopes in the proteomes of pathogenic bacteria. As a test case, we used this method to identify epitopes in the proteome of Francisella tularensis (Ft), a Select Agent with a well-characterized immunoproteome. Our screen identified many peptides that map to known antigens, including verified and predicted outer membrane proteins and extracellular proteins, validating the utility of this approach. We then used the method to identify seroreactive peptides in the less characterized immunoproteome of Select Agent Burkholderia pseudomallei (Bp). This screen revealed known Bp antigens as well as proteins that have not been previously identified as antigens. Although B-cell epitope prediction tools Bepipred 2.0 and iBCE-EL classified many of our seroreactive peptides as epitopes, they did not score them significantly higher than the non-reactive tryptic peptides in our study, nor did they assign higher scores to seroreactive peptides from known Ft or Bp antigens, highlighting the need for experimental data instead of relying on computational epitope predictions alone. The present workflow is easily adaptable to detecting peptide targets relevant to the immune systems of other mammalian species, including humans (depending upon the availability of convalescent sera from patients), and could aid in accelerating the discovery of B-cell epitopes and development of vaccines to counter emerging biological threats.
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Affiliation(s)
- Patrik D'haeseleer
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Nicole M Collette
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Victoria Lao
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Brent W Segelke
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Steven S Branda
- Molecular and Microbiology Department, Sandia National Laboratories, Livermore, CA, United States
| | - Magdalena Franco
- Biosciences and Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, CA, United States
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22
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Aitken EH, Damelang T, Ortega-Pajares A, Alemu A, Hasang W, Dini S, Unger HW, Ome-Kaius M, Nielsen MA, Salanti A, Smith J, Kent S, Hogarth PM, Wines BD, Simpson JA, Chung AW, Rogerson SJ. Developing a multivariate prediction model of antibody features associated with protection of malaria-infected pregnant women from placental malaria. eLife 2021; 10:e65776. [PMID: 34181872 PMCID: PMC8241440 DOI: 10.7554/elife.65776] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 06/16/2021] [Indexed: 12/15/2022] Open
Abstract
Background Plasmodium falciparum causes placental malaria, which results in adverse outcomes for mother and child. P. falciparum-infected erythrocytes that express the parasite protein VAR2CSA on their surface can bind to placental chondroitin sulfate A. It has been hypothesized that naturally acquired antibodies towards VAR2CSA protect against placental infection, but it has proven difficult to identify robust antibody correlates of protection from disease. The objective of this study was to develop a prediction model using antibody features that could identify women protected from placental malaria. Methods We used a systems serology approach with elastic net-regularized logistic regression, partial least squares discriminant analysis, and a case-control study design to identify naturally acquired antibody features mid-pregnancy that were associated with protection from placental malaria at delivery in a cohort of 77 pregnant women from Madang, Papua New Guinea. Results The machine learning techniques selected 6 out of 169 measured antibody features towards VAR2CSA that could predict (with 86% accuracy) whether a woman would subsequently have active placental malaria infection at delivery. Selected features included previously described associations with inhibition of placental binding and/or opsonic phagocytosis of infected erythrocytes, and network analysis indicated that there are not one but multiple pathways to protection from placental malaria. Conclusions We have identified candidate antibody features that could accurately identify malaria-infected women as protected from placental infection. It is likely that there are multiple pathways to protection against placental malaria. Funding This study was supported by the National Health and Medical Research Council (Nos. APP1143946, GNT1145303, APP1092789, APP1140509, and APP1104975).
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Affiliation(s)
- Elizabeth H Aitken
- Department of Medicine, University of Melbourne, the Doherty InstituteMelbourneAustralia
| | - Timon Damelang
- Department of Microbiology and Immunology, University of Melbourne, the Doherty InstituteMelbourneAustralia
| | - Amaya Ortega-Pajares
- Department of Medicine, University of Melbourne, the Doherty InstituteMelbourneAustralia
| | - Agersew Alemu
- Department of Medicine, University of Melbourne, the Doherty InstituteMelbourneAustralia
| | - Wina Hasang
- Department of Medicine, University of Melbourne, the Doherty InstituteMelbourneAustralia
| | - Saber Dini
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of MelbourneMelbourneAustralia
| | - Holger W Unger
- Department of Medicine, University of Melbourne, the Doherty InstituteMelbourneAustralia
- Department of Obstetrics and Gynaecology, Royal Darwin HospitalDarwinAustralia
- Menzies School of Health ResearchDarwinAustralia
| | - Maria Ome-Kaius
- Walter and Eliza Hall Institute of Medical ResearchParkvilleAustralia
| | - Morten A Nielsen
- Centre for Medical Parasitology, Department of Microbiology and immunology, University of CopenhagenCopenhagenDenmark
| | - Ali Salanti
- Centre for Medical Parasitology, Department of Microbiology and immunology, University of CopenhagenCopenhagenDenmark
- Department of Infectious Disease, Copenhagen University HospitalCopenhagenDenmark
| | - Joe Smith
- Seattle Children’s Research InstituteSeattleUnited States
- Department of Pediatrics, University of WashingtonSeattleUnited States
| | - Stephen Kent
- Department of Microbiology and Immunology, University of Melbourne, the Doherty InstituteMelbourneAustralia
| | - P Mark Hogarth
- Seattle Children’s Research InstituteSeattleUnited States
- Immune Therapies Group, Centre for Biomedical Research, Burnet InstituteMelbourneAustralia
- Department of Clinical Pathology, University of MelbourneMelbourneAustralia
- Department of Immunology and Pathology, Monash UniversityMelbourneAustralia
| | - Bruce D Wines
- Immune Therapies Group, Centre for Biomedical Research, Burnet InstituteMelbourneAustralia
- Department of Clinical Pathology, University of MelbourneMelbourneAustralia
- Department of Immunology and Pathology, Monash UniversityMelbourneAustralia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, University of MelbourneMelbourneAustralia
| | - Amy W Chung
- Department of Microbiology and Immunology, University of Melbourne, the Doherty InstituteMelbourneAustralia
| | - Stephen J Rogerson
- Department of Medicine, University of Melbourne, the Doherty InstituteMelbourneAustralia
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23
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McLean ARD, Opi DH, Stanisic DI, Cutts JC, Feng G, Ura A, Mueller I, Rogerson SJ, Beeson JG, Fowkes FJI. High Antibodies to VAR2CSA in Response to Malaria Infection Are Associated With Improved Birthweight in a Longitudinal Study of Pregnant Women. Front Immunol 2021; 12:644563. [PMID: 34220804 PMCID: PMC8242957 DOI: 10.3389/fimmu.2021.644563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Accepted: 05/17/2021] [Indexed: 11/23/2022] Open
Abstract
Introduction Pregnant women have an increased risk of P. falciparum infection, which is associated with low birth weight and preterm delivery. VAR2CSA, a variant surface antigen expressed on the parasitized erythrocyte surface, enables sequestration in the placenta. Few studies have prospectively examined relationships between antibody responses during pregnancy and subsequent adverse birth outcomes, and there are limited data outside Africa. Methods Levels of IgG against VAR2CSA domains (DBL3; DBL5) and a VAR2CSA-expressing placental-binding P. falciparum isolate (PfCS2-IE) were measured in 301 women enrolled at their first visit to antenatal care which occurred mid-pregnancy (median = 26 weeks, lower and upper quartiles = 22, 28). Associations between antibody levels at enrolment and placental infection, birthweight and estimated gestational age at delivery were assessed by linear and logistic regression with adjustment for confounders. For all outcomes, effect modification by gravidity and peripheral blood P. falciparum infection at enrolment was assessed. Results Among women who had acquired P. falciparum infection at enrolment, those with higher levels of VAR2CSA antibodies (75th percentile) had infants with higher mean birthweight (estimates varied from +35g to +149g depending on antibody response) and reduced adjusted odds of placental infection (aOR estimates varied from 0.17 to 0.80), relative to women with lower levels (25th percentile) of VAR2CSA antibodies. However, among women who had not acquired an infection at enrolment, higher VAR2CSA antibodies were associated with increased odds of placental infection (aOR estimates varied from 1.10 to 2.24). Conclusions When infected by mid-pregnancy, a better immune response to VAR2CSA-expressing parasites may contribute to protecting against adverse pregnancy outcomes.
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Affiliation(s)
- Alistair R D McLean
- Burnet Institute, Melbourne, VIC, Australia.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - D Herbert Opi
- Burnet Institute, Melbourne, VIC, Australia.,Department of Immunology and Pathology, Monash University, Melbourne, VIC, Australia.,Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Danielle I Stanisic
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.,Institute for Glycomics, Griffith University, Southport, QLD, Australia
| | - Julia C Cutts
- Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Gaoqian Feng
- Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Alice Ura
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea
| | - Ivo Mueller
- Papua New Guinea Institute of Medical Research, Madang, Papua New Guinea.,Population, Health and Immunity Division, Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Département Parasites et Insectes Vecteurs, Institute Pasteur, Paris, France
| | - Stephen J Rogerson
- Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - James G Beeson
- Burnet Institute, Melbourne, VIC, Australia.,Department of Medicine at the Doherty Institute, University of Melbourne, Melbourne, VIC, Australia.,Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Freya J I Fowkes
- Burnet Institute, Melbourne, VIC, Australia.,Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, VIC, Australia.,Centre for Epidemiology and Biostatistics, University of Melbourne, Melbourne, VIC, Australia.,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia
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24
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Pandey M, Rahi M, Sharma A. The Indian burden of malaria in pregnancy needs assessment. MED 2021; 2:464-469. [DOI: 10.1016/j.medj.2021.04.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 03/29/2021] [Accepted: 04/16/2021] [Indexed: 10/21/2022]
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25
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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.
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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
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Dombrowski JG, Barateiro A, Peixoto EPM, Barros ABCDS, de Souza RM, Clark TG, Campino S, Wrenger C, Wunderlich G, Palmisano G, Epiphanio S, Gonçalves LA, Marinho CRF. Adverse pregnancy outcomes are associated with Plasmodium vivax malaria in a prospective cohort of women from the Brazilian Amazon. PLoS Negl Trop Dis 2021; 15:e0009390. [PMID: 33914739 PMCID: PMC8112668 DOI: 10.1371/journal.pntd.0009390] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 05/11/2021] [Accepted: 04/15/2021] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Malaria in Brazil represents one of the highest percentages of Latin America cases, where approximately 84% of infections are attributed to Plasmodium (P.) vivax. Despite the high incidence, many aspects of gestational malaria resulting from P. vivax infections remain poorly studied. As such, we aimed to evaluate the consequences of P. vivax infections during gestation on the health of mothers and their neonates in an endemic area of the Amazon. METHODS AND FINDINGS We have conducted an observational cohort study in Brazilian Amazon between January 2013 and April 2015. 600 pregnant women were enrolled and followed until delivery. After applying exclusion criteria, 329 mother-child pairs were included in the analysis. Clinical data regarding maternal infection, newborn's anthropometric measures, placental histopathological characteristics, and angiogenic and inflammatory factors were evaluated. The presence of plasma IgG against the P. vivax (Pv) MSP119 protein was used as marker of exposure and possible associations with pregnancy outcomes were analyzed. Multivariate logistic regression analysis revealed that P. vivax infections during the first trimester of pregnancy are associated with adverse gestational outcomes such as premature birth (adjusted odds ratio [aOR] 8.12, 95% confidence interval [95%CI] 2.69-24.54, p < 0.0001) and reduced head circumference (aOR 3.58, 95%CI 1.29-9.97, p = 0.01). Histopathology analysis showed marked differences between placentas from P. vivax-infected and non-infected pregnant women, especially regarding placental monocytes infiltrate. Placental levels of vasomodulatory factors such as angiopoietin-2 (ANG-2) and complement proteins such as C5a were also altered at delivery. Plasma levels of anti-PvMSP119 IgG in infected pregnant women were shown to be a reliable exposure marker; yet, with no association with improved pregnancy outcomes. CONCLUSIONS This study indicates that P. vivax malaria during the first trimester of pregnancy represents a higher likelihood of subsequent poor pregnancy outcomes associated with marked placental histologic modification and angiogenic/inflammatory imbalance. Additionally, our findings support the idea that antibodies against PvMSP119 are not protective against poor pregnancy outcomes induced by P. vivax infections.
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Affiliation(s)
| | - André Barateiro
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | | | | | | | - Taane Gregory Clark
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Susana Campino
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Carsten Wrenger
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Gerhard Wunderlich
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Giuseppe Palmisano
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sabrina Epiphanio
- Department of Clinical and Toxicological Analyses, Faculty of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Lígia Antunes Gonçalves
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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27
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Chua CLL, Hasang W, Rogerson SJ, Teo A. Poor Birth Outcomes in Malaria in Pregnancy: Recent Insights Into Mechanisms and Prevention Approaches. Front Immunol 2021; 12:621382. [PMID: 33790894 PMCID: PMC8005559 DOI: 10.3389/fimmu.2021.621382] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 02/23/2021] [Indexed: 12/13/2022] Open
Abstract
Pregnant women in malaria-endemic regions are susceptible to malaria in pregnancy, which has adverse consequences on birth outcomes, including having small for gestational age and preterm babies. These babies are likely to have low birthweights, which predisposes to infant mortality and lifelong morbidities. During malaria in pregnancy, Plasmodium falciparum-infected erythrocytes express a unique variant surface antigen, VAR2CSA, that mediates sequestration in the placenta. This process may initiate a range of host responses that contribute to placental inflammation and dysregulated placental development, which affects placental vasculogenesis, angiogenesis and nutrient transport. Collectively, these result in the impairment of placental functions, affecting fetal development. In this review, we provide an overview of malaria in pregnancy and the different pathological pathways leading to malaria in pregnancy-associated low birthweight. We also discuss current prevention and management strategies for malaria in pregnancy, and some potential therapeutic interventions that may improve birth outcomes. Lastly, we outline some priorities for future research that could bring us one step closer to reducing this health burden.
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Affiliation(s)
| | - Wina Hasang
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Stephen J Rogerson
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia
| | - Andrew Teo
- Department of Medicine at Royal Melbourne Hospital, Peter Doherty Institute, University of Melbourne, Melbourne, VIC, Australia.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
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28
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Ma R, Lian T, Huang R, Renn JP, Petersen JD, Zimmerberg J, Duffy PE, Tolia NH. Structural basis for placental malaria mediated by Plasmodium falciparum VAR2CSA. Nat Microbiol 2021; 6:380-391. [PMID: 33452495 PMCID: PMC7914210 DOI: 10.1038/s41564-020-00858-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 12/17/2020] [Indexed: 01/29/2023]
Abstract
Plasmodium falciparum VAR2CSA binds to chondroitin sulfate A (CSA) on the surface of the syncytiotrophoblast during placental malaria. This interaction facilitates placental sequestration of malaria parasites resulting in severe health outcomes for both the mother and her offspring. Furthermore, CSA is presented by diverse cancer cells and specific targeting of cells by VAR2CSA may become a viable approach for cancer treatment. In the present study, we determined the cryo-electron microscopy structures of the full-length ectodomain of VAR2CSA from P. falciparum strain NF54 in complex with CSA, and VAR2CSA from a second P. falciparum strain FCR3. The architecture of VAR2CSA is composed of a stable core flanked by a flexible arm. CSA traverses the core domain by binding within two channels and CSA binding does not induce major conformational changes in VAR2CSA. The CSA-binding elements are conserved across VAR2CSA variants and are flanked by polymorphic segments, suggesting immune selection outside the CSA-binding sites. This work provides paths for developing interventions against placental malaria and cancer.
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Affiliation(s)
- Rui Ma
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Tengfei Lian
- Laboratory of Membrane Proteins and Structural Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Rick Huang
- Laboratory of Cell Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jonathan P. Renn
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Jennifer D. Petersen
- Section on Integrative Biophysics, Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Joshua Zimmerberg
- Section on Integrative Biophysics, Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Patrick E. Duffy
- Vaccine Development Unit, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA,Pathogenesis and Immunity Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Niraj H. Tolia
- Host-Pathogen Interactions and Structural Vaccinology Section, Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA,Correspondence: (N.H.T.)
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29
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Vanda K, Bobbili N, Matsunaga M, Chen JJ, Salanti A, Leke RFG, Taylor DW. The Development, Fine Specificity, and Importance of High-Avidity Antibodies to VAR2CSA in Pregnant Cameroonian Women Living in Yaoundé, an Urban City. Front Immunol 2021; 12:610108. [PMID: 33717094 PMCID: PMC7953046 DOI: 10.3389/fimmu.2021.610108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 01/07/2021] [Indexed: 11/25/2022] Open
Abstract
Pregnant women infected with Plasmodium falciparum often produce antibodies (Abs) to VAR2CSA, a ligand that binds to placental chondroitin sulfate A causing placental malaria (PM). Antibodies to VAR2CSA are associated with improved pregnancy outcomes. Antibody avidity is a surrogate marker for the extent of maturation of the humoral immune response. Little is known about high avidity Abs to VAR2CSA for women living in urban African cities. Therefore, this study sought to determine: i) if high avidity Abs to full-length VAR2CSA (FV2) increase with gravidity in women in Yaoundé, Cameroon exposed to ~ 0.3-1.1 infectious mosquito bites per month, ii) if high avidity Abs to FV2 are directed against a specific region of VAR2CSA, and iii) if having high avidity Abs to FV2 improve pregnancy outcomes. Plasma samples collected at delivery from 695 women who had Abs to FV2 were evaluated. Ab levels and the Avidity Index (AI), defined as the percent Abs remaining bound to FV2 after incubation with 3M NH4SCN, were determined. Similar Ab levels to FV2 were present in women of all gravidities (G1 through 6+; p=0.80), except significantly lower levels were detected in PM−negative (PM−) primigravidae (p <0.001). Median Ab avidities increased between gravidity 1 and 2 (p<0.001) and remained stable thereafter (G3-G6+: p=0.51). These results suggest that B cell clonal expansion began during the first pregnancy, with clonal selection primarily occurring during the second. However, the majority of women (84%) had AI <35, a level of high avidity Abs previously reported to be associated with improved pregnancy outcomes. When plasma from 107 Cameroonian women was tested against 8 different regions of FV2, high avidity Abs were predominately restricted to DBL5 with median AI of 50 compared to AI <25 for the other domains. The only significance influence of high avidity Abs on pregnancy outcome was that babies born to mothers with AI above the median were 104 g heavier than babies born to women with AI below the median (p=0.045). These results suggest that a vaccine that boosts maturation of the immune response to VAR2CSA may be beneficial for women residing in urban areas.
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Affiliation(s)
- Koko Vanda
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, United States
| | - Naveen Bobbili
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, United States
| | - Masako Matsunaga
- Department of Quantitative Health Sciences, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, United States
| | - John J Chen
- Department of Quantitative Health Sciences, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, United States
| | - Ali Salanti
- Centre for Medical Parasitology, Department for Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen and Department of Infectious Disease, Copenhagen University Hospital, Copenhagen, Denmark
| | - Rose F G Leke
- Faculty of Medicine and Biomedical Research, The Biotechnology Center, University of Yaoundé 1, Yaoundé, Cameroon
| | - Diane Wallace Taylor
- Department of Tropical Medicine, Medical Microbiology and Pharmacology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, United States
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30
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Tomlinson A, Semblat JP, Gamain B, Chêne A. VAR2CSA-Mediated Host Defense Evasion of Plasmodium falciparum Infected Erythrocytes in Placental Malaria. Front Immunol 2021; 11:624126. [PMID: 33633743 PMCID: PMC7900151 DOI: 10.3389/fimmu.2020.624126] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/23/2020] [Indexed: 12/04/2022] Open
Abstract
Over 30 million women living in P. falciparum endemic areas are at risk of developing malaria during pregnancy every year. Placental malaria is characterized by massive accumulation of infected erythrocytes in the intervillous space of the placenta, accompanied by infiltration of immune cells, particularly monocytes. The consequent local inflammation and the obstruction of the maternofetal exchanges can lead to severe clinical outcomes for both mother and child. Even if protection against the disease can gradually be acquired following successive pregnancies, the malaria parasite has developed a large panel of evasion mechanisms to escape from host defense mechanisms and manipulate the immune system to its advantage. Infected erythrocytes isolated from placentas of women suffering from placental malaria present a unique phenotype and express the pregnancy-specific variant VAR2CSA of the Plasmodium falciparum Erythrocyte Membrane Protein (PfEMP1) family at their surface. The polymorphic VAR2CSA protein is able to mediate the interaction of infected erythrocytes with a variety of host cells including placental syncytiotrophoblasts and leukocytes but also with components of the immune system such as non-specific IgM. This review summarizes the described VAR2CSA-mediated host defense evasion mechanisms employed by the parasite during placental malaria to ensure its survival and persistence.
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Affiliation(s)
- Alice Tomlinson
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, Paris, France.,Institut National de la Transfusion Sanguine, Paris, France.,Laboratory of Excellence GR-Ex, Paris, France
| | - Jean-Philippe Semblat
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, Paris, France.,Institut National de la Transfusion Sanguine, Paris, France.,Laboratory of Excellence GR-Ex, Paris, France
| | - Benoît Gamain
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, Paris, France.,Institut National de la Transfusion Sanguine, Paris, France.,Laboratory of Excellence GR-Ex, Paris, France
| | - Arnaud Chêne
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, Paris, France.,Institut National de la Transfusion Sanguine, Paris, France.,Laboratory of Excellence GR-Ex, Paris, France
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31
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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.
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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
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32
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Rönnberg C, Lugaajju A, Nyman A, Hammar U, Bottai M, Lautenbach MJ, Sundling C, Kironde F, Persson KEM. A longitudinal study of plasma BAFF levels in mothers and their infants in Uganda, and correlations with subsets of B cells. PLoS One 2021; 16:e0245431. [PMID: 33465125 PMCID: PMC7815132 DOI: 10.1371/journal.pone.0245431] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 01/03/2021] [Indexed: 01/05/2023] Open
Abstract
Malaria is a potentially life-threatening disease with approximately half of the world’s population at risk. Young children and pregnant women are hit hardest by the disease. B cells and antibodies are part of an adaptive immune response protecting individuals continuously exposed to the parasite. An infection with Plasmodium falciparum can cause dysregulation of B cell homeostasis, while antibodies are known to be key in controlling symptoms and parasitemia. BAFF is an instrumental cytokine for the development and maintenance of B cells. Pregnancy alters the immune status and renders previously clinically immune women at risk of severe malaria, potentially due to altered B cell responses associated with changes in BAFF levels. In this prospective study, we investigated the levels of BAFF in a malaria-endemic area in mothers and their infants from birth up to 9 months. We found that BAFF-levels are significantly higher in infants than in mothers. BAFF is highest in cord blood and then drops rapidly, but remains significantly higher in infants compared to mothers even at 9 months of age. We further correlated BAFF levels to P. falciparum-specific antibody levels and B cell frequencies and found a negative correlation between BAFF and both P. falciparum-specific and total proportions of IgG+ memory B cells, as well as CD27− memory B cells, indicating that exposure to both malaria and other diseases affect the development of B-cell memory and that BAFF plays a part in this. In conclusion, we have provided new information on how natural immunity against malaria is formed.
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Affiliation(s)
- Caroline Rönnberg
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Division of Infectious Diseases, Department of Medicine Solna, and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Allan Lugaajju
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm, Sweden
- Makerere University, Kampala, Uganda
| | - Anna Nyman
- Department of Laboratory Medicine, Lund University, Skåne University Hospital, Lund, Sweden
| | - Ulf Hammar
- Division of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Matteo Bottai
- Division of Biostatistics, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Maximilian Julius Lautenbach
- Division of Infectious Diseases, Department of Medicine Solna, and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Christopher Sundling
- Division of Infectious Diseases, Department of Medicine Solna, and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- Department of Infectious Diseases, Karolinska University Hospital, Stockholm, Sweden
| | - Fred Kironde
- Makerere University, Kampala, Uganda
- Habib Medical School, Islamic University in Uganda (IUIU), Mbale, Uganda
| | - Kristina E. M. Persson
- Department of Laboratory Medicine, Lund University, Skåne University Hospital, Lund, Sweden
- * E-mail:
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33
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Wiebe MC, Yanow SK. Do Antibodies to Malaria Surface Antigens Play a Role in Protecting Mothers From Maternal Anemia? Front Immunol 2020; 11:609957. [PMID: 33391279 PMCID: PMC7775498 DOI: 10.3389/fimmu.2020.609957] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/17/2020] [Indexed: 11/13/2022] Open
Abstract
Pregnancy-associated malaria (PAM) caused by Plasmodium falciparum can result in detrimental outcomes for both mother and infant, including low infant birth weight, preterm birth, maternal anemia, spontaneous abortion, and maternal and/or infant mortality. Maternal anemia is a particularly complex outcome, as the body must both maintain erythropoiesis and tolerance of the growing fetus, while directing a Th1 response against the parasite. Underlying the pathogenesis of PAM is the expression of variant surface antigens (VSAPAM) on the surface of infected red blood cells (iRBC) that mediate sequestration of the iRBC in the placenta. Naturally acquired antibodies to VSAPAM can block sequestration and activate opsonic phagocytosis, both associated with improved pregnancy outcomes. In this review, we ask whether VSAPAM antibodies can also protect mothers against malarial anemia. Studies were identified where VSAPAM antibody titres and/or function were associated with higher maternal hemoglobin levels, thus supporting additional protective mechanisms for these antibodies against PAM. Yet these associations were not widely observed, and many studies reported no association between protection from maternal anemia and VSAPAM antibodies. We discuss the epidemiological, biological and technical factors that may explain some of the variability among these studies. We appraise the current evidence of these complex interactions between PAM-specific immunity and maternal anemia, propose potential mechanisms, and discuss knowledge gaps.
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Affiliation(s)
- Madeleine C Wiebe
- 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
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34
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Agyeman YN, Newton SK, Annor RB, Owusu-Dabo E. The Effectiveness of the Revised Intermittent Preventive Treatment with Sulphadoxine Pyrimethamine (IPTp-SP) in the Prevention of Malaria among Pregnant Women in Northern Ghana. J Trop Med 2020; 2020:2325304. [PMID: 33299426 PMCID: PMC7704196 DOI: 10.1155/2020/2325304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/09/2020] [Accepted: 10/26/2020] [Indexed: 11/28/2022] Open
Abstract
This study investigated the effectiveness of the World Health Organization (WHO)-revised Intermittent Preventive Treatment using Sulphadoxine Pyrimethamine (IPTp-SP) dosage regimen in the prevention of malaria infections in pregnancy. The study involved a prospective cohort of pregnant women who attended the antenatal clinic in four health facilities (Tamale Teaching Hospital, Tamale West Hospital, Tamale Central Hospital, and Tamale SDA Hospital) within the Tamale metropolis. Data collection spanned a period of 12 months, from September 2016 to August 2017, to help account for seasonality in malaria. The study included 1181 pregnant women who attended antenatal clinics in four hospitals within the metropolis. The registers at the facilities served as a sampling frame, and the respondents were randomly sampled out from the number of pregnant women available during each visit. They were enrolled consecutively as they kept reporting to the facility to receive antenatal care. The participants were stratified into three groups; the no IPTp-SP, <3 doses of IPTp-SP, and ≥3 doses of IPTp-SP. The participants were followed up until 36 weeks of gestation, and blood samples were analyzed to detect the presence of peripheral malaria parasites. At the end of the study, 42.4% of the women had taken at least 3 doses of SP based on the revised WHO IPTp-SP policy. Pregnant women who had taken at least 3 doses of IPTp-SP had a malaria prevalence of 16.9% at 36 weeks of gestation, compared to 35.8% of those who had not taken IPTp-SP. In the multivariable logistic regression, those who had taken ≥3 doses of SP were associated with 56% reduced odds (aOR 0.44, CI 0.27-0.70, P = 0.001) of late gestational peripheral malaria, compared with those who did not take SP. IPTp-SP served under three or more doses provided a dose-dependent protection of 56% against maternal peripheral malaria parasitaemia detectable at the later stages of gestation (36 weeks). Since the dose-dependent potency of IPTp-SP depletes with time, there is the need for research into more sustainable approaches that offer longer protection.
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Affiliation(s)
- Yaa Nyarko Agyeman
- Department of Population and Reproductive Health, School of Public Health, University for Development Studies, Tamale, Ghana
| | - Sam Kofi Newton
- Department of Global and International Health, School of Public Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Ellis Owusu-Dabo
- Department of Global and International Health, School of Public Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
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35
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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.
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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
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36
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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.
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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
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Doesn’t It All Come Down to Function? How To Correlate VAR2CSA Antibodies with Protection. mSphere 2020; 5:5/3/e00521-20. [PMID: 32581073 PMCID: PMC7316495 DOI: 10.1128/msphere.00521-20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Thompson JM, Eick SM, Dailey C, Dale AP, Mehta M, Nair A, Cordero JF, Welton M. Relationship Between Pregnancy-Associated Malaria and Adverse Pregnancy Outcomes: a Systematic Review and Meta-Analysis. J Trop Pediatr 2020; 66:327-338. [PMID: 31598714 DOI: 10.1093/tropej/fmz068] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Pregnancy-associated malaria (PAM) has been associated with adverse pregnancy outcomes like preterm birth (PTB) and low birthweight (LBW), which are among the leading causes of infant mortality globally. Rates of PTB and LBW are high in countries with a high burden of malaria. PAM may be a contributing factor to PTB and LBW, but is not well understood. METHODS We conducted a systematic review and meta-analysis of studies examining the relationship between PAM and PTB or LBW using PubMed. The title and abstract of all studies were screened by two reviewers, and the full text of selected studies was reviewed to ensure they met inclusion criteria. Information regarding study characteristics and of PTB and LBW births among women with and without PAM was abstracted for included studies. RESULTS Our search terms yielded 2237 articles, of which 18 met our final inclusion criteria. Eight studies examined associations between PAM and PTB, and 10 examined associations between PAM and LBW (population size ranging from 35 to 9956 women). The overall risk of LBW was 63% higher among women with PAM compared with women without PAM (95% CI = 1.48-1.80) and the risk of PTB was 23% higher among women with PAM compared with women without PAM (95% CI = 1.07-1.41). CONCLUSIONS These results indicate that infection with PAM is associated with PTB and LBW. Further understanding of the pathogenesis of disease and the immunologic changes that occur during pregnancy is essential for reducing the disproportional effects this disease has on this vulnerable population.
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Affiliation(s)
- Julie M Thompson
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 30605 Athens, GA, USA.,College of Veterinary Medicine, University of Georgia, 30602 Athens, GA, USA
| | - Stephanie M Eick
- Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Services, University of California, San Francisco, 94158 San Francisco, CA, USA
| | - Cody Dailey
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 30605 Athens, GA, USA.,Odum School of Ecology, University of Georgia, 30602 Athens, GA, USA
| | - Ariella P Dale
- Colorado Department of Public Health & Environment, 80246 Denver, CO, USA
| | - Mansi Mehta
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 30605 Athens, GA, USA
| | - Anjali Nair
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 30605 Athens, GA, USA
| | - José F Cordero
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 30605 Athens, GA, USA
| | - Michael Welton
- Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, 30605 Athens, GA, USA
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PRIMVAC vaccine adjuvanted with Alhydrogel or GLA-SE to prevent placental malaria: a first-in-human, randomised, double-blind, placebo-controlled study. THE LANCET. INFECTIOUS DISEASES 2020; 20:585-597. [DOI: 10.1016/s1473-3099(19)30739-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/22/2019] [Accepted: 12/03/2019] [Indexed: 10/25/2022]
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40
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Cutts JC, Agius PA, Zaw Lin, Powell R, Moore K, Draper B, Simpson JA, Fowkes FJI. Pregnancy-specific malarial immunity and risk of malaria in pregnancy and adverse birth outcomes: a systematic review. BMC Med 2020; 18:14. [PMID: 31941488 PMCID: PMC6964062 DOI: 10.1186/s12916-019-1467-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 11/11/2019] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND In endemic areas, pregnant women are highly susceptible to Plasmodium falciparum malaria characterized by the accumulation of parasitized red blood cells (pRBC) in the placenta. In subsequent pregnancies, women develop protective immunity to pregnancy-associated malaria and this has been hypothesized to be due to the acquisition of antibodies to the parasite variant surface antigen VAR2CSA. In this systematic review we provide the first synthesis of the association between antibodies to pregnancy-specific P. falciparum antigens and pregnancy and birth outcomes. METHODS We conducted a systematic review and meta-analysis of population-based studies (published up to 07 June 2019) of pregnant women living in P. falciparum endemic areas that examined antibody responses to pregnancy-specific P. falciparum antigens and outcomes including placental malaria, low birthweight, preterm birth, peripheral parasitaemia, maternal anaemia, and severe malaria. RESULTS We searched 6 databases and identified 33 studies (30 from Africa) that met predetermined inclusion and quality criteria: 16 studies contributed estimates in a format enabling inclusion in meta-analysis and 17 were included in narrative form only. Estimates were mostly from cross-sectional data (10 studies) and were heterogeneous in terms of magnitude and direction of effect. Included studies varied in terms of antigens tested, methodology used to measure antibody responses, and epidemiological setting. Antibody responses to pregnancy-specific pRBC and VAR2CSA antigens, measured at delivery, were associated with placental malaria (9 studies) and may therefore represent markers of infection, rather than correlates of protection. Antibody responses to pregnancy-specific pRBC, but not recombinant VAR2CSA antigens, were associated with trends towards protection from low birthweight (5 studies). CONCLUSIONS Whilst antibody responses to several antigens were positively associated with the presence of placental and peripheral infections, this review did not identify evidence that any specific antibody response is associated with protection from pregnancy-associated malaria across multiple populations. Further prospective cohort studies using standardized laboratory methods to examine responses to a broad range of antigens in different epidemiological settings and throughout the gestational period, will be necessary to identify and prioritize pregnancy-specific P. falciparum antigens to advance the development of vaccines and serosurveillance tools targeting pregnant women.
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Affiliation(s)
- Julia C Cutts
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia.
| | - Paul A Agius
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia.,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
| | - Zaw Lin
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Rosanna Powell
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia
| | - Kerryn Moore
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia.,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Bridget Draper
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia
| | - Julie A Simpson
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia
| | - Freya J I Fowkes
- Burnet Institute, 85 Commercial Road, Melbourne, Victoria, 3004, Australia. .,Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia. .,Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Australia. .,Department of Infectious Diseases, Monash University, Melbourne, Australia.
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41
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Doritchamou JYA, Morrison R, Renn JP, Ribeiro J, Duan J, Fried M, Duffy PE. Placental malaria vaccine candidate antigen VAR2CSA displays atypical domain architecture in some Plasmodium falciparum strains. Commun Biol 2019; 2:457. [PMID: 31840102 PMCID: PMC6897902 DOI: 10.1038/s42003-019-0704-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 11/13/2019] [Indexed: 12/15/2022] Open
Abstract
Two vaccines based on Plasmodium falciparum protein VAR2CSA are currently in clinical evaluation to prevent placental malaria (PM), but a deeper understanding of var2csa variability could impact vaccine design. Here we identified atypical extended or truncated VAR2CSA extracellular structures and confirmed one extended structure in a Malian maternal isolate, using a novel protein fragment assembly method for RNA-seq and DNA-seq data. Extended structures included one or two additional DBL domains downstream of the conventional NTS-DBL1X-6ɛ domain structure, with closest similarity to DBLɛ in var2csa and non-var2csa genes. Overall, 4/82 isolates displayed atypical VAR2CSA structures. The maternal isolate expressing an extended VAR2CSA bound to CSA, but its recombinant VAR2CSA bound less well to CSA than VAR2CSANF54 and showed lower reactivity to naturally acquired parity-dependent antibody. Our protein fragment sequence assembly approach has revealed atypical VAR2CSA domain architectures that impact antigen reactivity and function, and should inform the design of VAR2CSA-based vaccines.
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Affiliation(s)
- Justin Y. A. Doritchamou
- Laboratory of Malaria Immunology & Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD USA
| | - Robert Morrison
- Laboratory of Malaria Immunology & Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD USA
| | - Jonathan P. Renn
- Laboratory of Malaria Immunology & Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD USA
| | - Jose Ribeiro
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD USA
| | - Junhui Duan
- Laboratory of Malaria Immunology & Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD USA
| | - Michal Fried
- Laboratory of Malaria Immunology & Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD USA
| | - Patrick E. Duffy
- Laboratory of Malaria Immunology & Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD USA
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42
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Functional Antibodies against Placental Malaria Parasites Are Variant Dependent and Differ by Geographic Region. Infect Immun 2019; 87:IAI.00865-18. [PMID: 30988054 DOI: 10.1128/iai.00865-18] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 04/05/2019] [Indexed: 02/06/2023] Open
Abstract
During pregnancy, Plasmodium falciparum-infected erythrocytes (IE) accumulate in the intervillous spaces of the placenta by binding to chondroitin sulfate A (CSA) and elicit inflammatory responses that are associated with poor pregnancy outcomes. Primigravidae lack immunity to IE that sequester in the placenta and thus are susceptible to placental malaria (PM). Women become resistant to PM over successive pregnancies as antibodies to placental IE are acquired. Here, we assayed plasma collected at delivery from Malian and Tanzanian women of different parities for total antibody levels against recombinant VAR2CSA antigens (FCR3 allele), and for surface reactivity and binding inhibition and opsonizing functional activities against IE using two CSA-binding laboratory isolates (FCR3 and NF54). Overall, antibody reactivity to VAR2CSA recombinant proteins and to CSA-binding IE was higher in multigravidae than in primigravidae. However, plasma from Malian gravid women reacted more strongly with FCR3 whereas Tanzanian plasma preferentially reacted with NF54. Further, acquisition of functional antibodies was variant dependent: binding inhibition of P. falciparum strain NF54 (P < 0.001) but not of the strain FCR3 increased significantly with parity, while only opsonizing activity against FCR3 (P < 0.001) increased significantly with parity. In addition, opsonizing and binding inhibition activities of plasma of multigravidae were significantly correlated in assays of FCR3 (r = 0.4, P = 0.01) but not of NF54 isolates; functional activities did not correlate in plasma from primigravidae. These data suggest that IE surface-expressed epitopes involved in each functional activity differ among P. falciparum strains. Consequently, geographic bias in circulating strains may impact antibody functions. Our study has implications for the development of PM vaccines aiming to achieve broad protection against various parasite strains.
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Intermittent screening and treatment with dihydroartemisinin-piperaquine and intermittent preventive therapy with sulfadoxine-pyrimethamine have similar effects on malaria antibody in pregnant Malawian women. Sci Rep 2019; 9:7878. [PMID: 31133672 PMCID: PMC6536723 DOI: 10.1038/s41598-019-44340-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 05/15/2019] [Indexed: 11/08/2022] Open
Abstract
In a randomised trial comparing intermittent screening and treatment (IST) with dihydroartemisinin-piperaquine (DP) and intermittent preventive therapy against malaria in pregnancy (IPT) with sulfadoxine-pyrimethamine (SP) in Malawi, the impacts of IST-DP and IPT-SP on the development and maintenance of malaria antibody immunity were compared. Pregnant Malawian women were randomised to receive IST-DP or IPT-SP. In a nested study, paired enrolment and delivery plasma samples from 681 women were assayed for antibodies against recombinant antigens and for IgG and opsonising antibodies to antigens found on infected erythrocytes (IEs). At delivery, antibody responses did not differ between study arms. Between enrolment and delivery, antibodies to recombinant antigens decreased, whereas antibodies to IEs including opsonising antibodies remained stable. Overall, changes in antibody responses over pregnancy did not differ by treatment arm. Stratifying by gravidity, antibody to schizont extract decreased more in multigravidae receiving IST-DP than IPT-SP. There was minimal impact of treatment arm on the development and maintenance of malaria immunity. While antibodies to recombinant antigens declined between enrolment and delivery, antibodies directed against IEs tended to be more stable, suggesting longer-lasting protection.Clinical trial registration: Pa n African Clinical Trials Registry (PACTR201103000280319) 14/03/2011. URL: http://www.isrctn.com/ISRCTN69800930 .
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Attaher O, Mahamar A, Swihart B, Barry A, Diarra BS, Kanoute MB, Dembele AB, Keita S, Gaoussou S, Issiaka D, Dicko A, Duffy PE, Fried M. Age-dependent increase in antibodies that inhibit Plasmodium falciparum adhesion to a subset of endothelial receptors. Malar J 2019; 18:128. [PMID: 30971252 PMCID: PMC6458601 DOI: 10.1186/s12936-019-2764-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 04/03/2019] [Indexed: 11/30/2022] Open
Abstract
Background Plasmodium falciparum-infected erythrocytes (IE) sequester in deep vascular beds where their adhesion is mediated by an array of endothelial surface receptors. Because parasite adhesion has been associated with disease, antibodies that block this activity may confer protective immunity. Here, levels of plasma anti-adhesion activity and surface reactivity against freshly collected IEs from malaria-infected children were measured in a Malian birth cohort and related to child age and malaria infection history. Methods Plasma samples from children enrolled at birth in a longitudinal cohort study of mother–infant pairs in Ouelessebougou, Mali were collected at multiple time points during follow-up visits. Anti-adhesion antibodies (i.e., inhibit IE binding to any of several endothelial receptors) and reactivity with surface IE proteins were measured using a binding inhibition assay and by flow cytometry, respectively. Results Levels of antibodies that inhibit the binding of children’s IE to the receptors ICAM-1, integrin α3β1 and laminin increased with age. The breadth of antibodies that inhibit ICAM-1 and laminin adhesion (defined as the proportion of IE isolates whose binding was reduced by ≥ 50%) also significantly increased with age. The number of malaria infections prior to plasma collection was associated with levels of plasma reactivity to IE surface proteins, but not levels of anti-adhesion activity. Conclusions Age is associated with increased levels of antibodies that reduce adhesion of children’s IE to three of the ten endothelial receptors evaluated here. These results suggest that anti-adhesion antibodies to some but not all endothelial receptors are acquired during the first few years of life. Electronic supplementary material The online version of this article (10.1186/s12936-019-2764-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- 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
| | - 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
| | - Bruce Swihart
- Biostatistics Research Branch, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, 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
| | - 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
| | - 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
| | - 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
| | - Santara Gaoussou
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - Djibrilla Issiaka
- Malaria Research & Training Center, Faculty of Medicine, Pharmacy and Dentistry, University of Sciences Techniques and Technologies of Bamako, P.O Box 1805, Bamako, Mali
| | - 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
| | - Michal Fried
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, USA.
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Chauvet M, Tétard M, Cottrell G, Aussenac F, Brossier E, Denoyel L, Hanny M, Lohezic M, Milet J, Ndam NT, Pineau D, Roman J, Luty AJF, Gamain B, Migot-Nabias F, Merckx A. Impact of Hemoglobin S Trait on Cell Surface Antibody Recognition of Plasmodium falciparum-Infected Erythrocytes in Pregnancy-Associated Malaria. Open Forum Infect Dis 2019; 6:ofz156. [PMID: 31041352 PMCID: PMC6483131 DOI: 10.1093/ofid/ofz156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 03/21/2019] [Indexed: 11/24/2022] Open
Abstract
Background Sickle cell trait (HbAS) confers partial protection against malaria by reducing the adhesion of Plasmodium falciparum-infected erythrocytes to host receptors, but little is known about its potential protection against placental malaria. Methods Using flow cytometry, we assessed the recognition of HbAA and HbAS VAR2CSA-expressing infected erythrocytes, by plasma from 159 Beninese pregnant women with either HbAA (normal) or HbAS. Using multivariate linear models adjusted for gravidity, parasite infection at delivery, glucose-6-phosphate dehydrogenase deficiency, and α-thalassemia carriage, we observed significantly reduced cell surface antibody binding of HbAS-infected erythrocytes by plasma from HbAS compared with HbAA women (P < 10–3). Results The difference in cell surface antibody binding was only observed when infected erythrocytes and plasma were associated according to the same hemoglobin genotype. Similar levels of VAR2CSA-specific antibody were measured by enzyme-linked immunosorbent assay in the 2 groups, suggesting that the altered interaction between VAR2CSA and HbAS women’s antibodies could reflect abnormal display of VAR2CSA on HbAS erythrocytes. Conclusions Our data stress the need for assessments of erythrocyte disorders such as the sickle cell trait in a population group when studying immunological responses to P falciparum.
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Affiliation(s)
- Margaux Chauvet
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France.,Laboratoire d'Excellence GR-Ex, Paris, France
| | - Marilou Tétard
- UMR_S1134, Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, Paris, France
| | - Gilles Cottrell
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France.,Centre d'Etude et de Recherche pour le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Florentin Aussenac
- Centre d'Etude et de Recherche pour le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Emeline Brossier
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France
| | - Luc Denoyel
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France
| | - Marion Hanny
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France
| | - Murielle Lohezic
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France.,Laboratoire d'Excellence GR-Ex, Paris, France
| | - Jacqueline Milet
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France
| | - Nicaise Tuikue Ndam
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France.,Laboratoire d'Excellence GR-Ex, Paris, France.,Department of Parasitology, Noguchi Memorial Institute for Medical Research, College of Health Sciences, University of Ghana, Legon
| | - Damien Pineau
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France
| | - Jocelyne Roman
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France
| | - Adrian J F Luty
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France.,Laboratoire d'Excellence GR-Ex, Paris, France.,Centre d'Etude et de Recherche pour le Paludisme Associé à la Grossesse et à l'Enfance, Cotonou, Benin
| | - Benoît Gamain
- UMR_S1134, Université Sorbonne Paris Cité, Université Paris Diderot, Inserm, INTS, Unité Biologie Intégrée du Globule Rouge, Laboratoire d'Excellence GR-Ex, Paris, France
| | - Florence Migot-Nabias
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France.,Laboratoire d'Excellence GR-Ex, Paris, France
| | - Anaïs Merckx
- MERIT, Institut de Recherche pour le Développement (IRD), Université Sorbonne Paris Cité, Université Paris Descartes, France.,Laboratoire d'Excellence GR-Ex, Paris, France
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Janitzek CM, Peabody J, Thrane S, H R Carlsen P, G Theander T, Salanti A, Chackerian B, A Nielsen M, Sander AF. A proof-of-concept study for the design of a VLP-based combinatorial HPV and placental malaria vaccine. Sci Rep 2019; 9:5260. [PMID: 30918267 PMCID: PMC6437161 DOI: 10.1038/s41598-019-41522-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/08/2019] [Indexed: 11/16/2022] Open
Abstract
In Africa, cervical cancer and placental malaria (PM) are a major public health concern. There is currently no available PM vaccine and the marketed Human Papillomavirus (HPV) vaccines are prohibitively expensive. The idea of a combinatorial HPV and PM vaccine is attractive because the target population for vaccination against both diseases, adolescent girls, would be overlapping in Sub-Saharan Africa. Here we demonstrate proof-of-concept for a combinatorial vaccine utilizing the AP205 capsid-based virus-like particle (VLP) designed to simultaneously display two clinically relevant antigens (the HPV RG1 epitope and the VAR2CSA PM antigen). Three distinct combinatorial VLPs were produced displaying one, two or five concatenated RG1 epitopes without obstructing the VLP’s capacity to form. Co-display of VAR2CSA was achieved through a split-protein Tag/Catcher interaction without hampering the vaccine stability. Vaccination with the combinatorial vaccine(s) was able to reduce HPV infection in vivo and induce anti-VAR2CSA IgG antibodies, which inhibited binding between native VAR2CSA expressed on infected red blood cells and chondroitin sulfate A in an in vitro binding-inhibition assay. These results show that the Tag/Catcher AP205 VLP system can be exploited to make a combinatorial vaccine capable of eliciting antibodies with dual specificity.
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Affiliation(s)
- Christoph M 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
| | - Julianne Peabody
- Department of Molecular Genetics & Microbiology, University of New Mexico School of Medicine, Albuquerque, USA
| | - Susan Thrane
- 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
| | - Philip H R Carlsen
- 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
| | - 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
| | - 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
| | - Bryce Chackerian
- Department of Molecular Genetics & Microbiology, University of New Mexico School of Medicine, Albuquerque, 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
| | - 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.
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47
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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.
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48
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Abstract
Pregnant women are especially susceptible to malaria infection. Without existing immunity, severe malaria can develop requiring emergency treatment, and pregnancy loss is common. In semi-immune women, consequences of malaria for the mother include anaemia while stillbirth, premature delivery and foetal growth restriction affect the developing foetus. Preventive measures include insecticide-treated nets and (in some African settings) intermittent preventive treatment. Prompt management of maternal infection is key, using parenteral artemisinins for severe malaria, and artemisinin combination treatments (ACTs) in the second and third trimesters of pregnancy. ACTs may soon also be recommended as an alternative to quinine as a treatment in the first trimester of pregnancy. Monitoring the safety of antimalarials and understanding their pharmacokinetics is particularly important in pregnancy with the altered maternal physiology and the risks to the developing foetus. As increasing numbers of countries embrace malaria elimination as a goal, the special needs of the vulnerable group of pregnant women and their infants should not be overlooked.
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Affiliation(s)
- Stephen J Rogerson
- Department of Medicine at the Doherty Institute, The University of Melbourne, Melbourne, Australia
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49
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Association of Antibodies to VAR2CSA and Merozoite Antigens with Pregnancy Outcomes in Women Living in Yaoundé, Cameroon. Infect Immun 2018; 86:IAI.00166-18. [PMID: 29986889 DOI: 10.1128/iai.00166-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/22/2018] [Indexed: 11/20/2022] Open
Abstract
Plasmodium falciparum infections are serious in pregnant women, because VAR2CSA allows parasitized erythrocytes to sequester in the placenta, causing placental malaria (PM). In areas of endemicity, women have substantial malarial immunity prior to pregnancy, including antibodies to merozoite antigens, but produce antibodies to VAR2CSA only during pregnancy. The current study sought to determine the importance of antibodies to VAR2CSA and merozoite antigens in pregnant women in Yaoundé, Cameroon, where malaria transmission was relatively low. A total of 1,377 archival plasma samples collected at delivery were selected (at a 1:3 ratio of PM-positive [PM+] to PM-negative [PM-] women) and screened for antibodies to full-length VAR2CSA and 7 merozoite antigens. Results showed that many PM+ women and most PM- women lacked antibodies to VAR2CSA at delivery. Among PM+ women, antibodies to VAR2CSA were associated with a reduced risk of having high placental parasitemia (odds ratio [OR], 0.432; confidence interval [CI], 0.272, 0.687; P = 0.0004) and low-birth-weight (LBW) babies (OR = 0.444; CI, 0.247, 0.799; P = 0.0068), even during first pregnancies. Among antibodies to the 7 merozoite antigens, i.e., AMA1, EBA-175, MSP142, MSP2, MSP3, MSP11, and Pf41, only antibodies to MSP3, EBA-175, and Pf41 were associated with reduced risk for high placental parasitemias (P = 0.0389, 0.0291, and 0.0211, respectively) and antibodies to EBA-175 were associated with reduced risk of premature deliveries (P = 0.0211). However, after adjusting for multiple comparisons significance declined. Thus, in PM+ women, antibodies to VAR2CSA were associated with lower placental parasitemias and reduced prevalence of LBW babies in this low-transmission setting.
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50
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Gavina K, Gnidehou S, Arango E, Hamel-Martineau C, Mitran C, Agudelo O, Lopez C, Karidio A, Banman S, Carmona-Fonseca J, Salanti A, Tuikue Ndam N, Hawkes M, Maestre A, Yanow SK. Clinical Outcomes of Submicroscopic Infections and Correlates of Protection of VAR2CSA Antibodies in a Longitudinal Study of Pregnant Women in Colombia. Infect Immun 2018; 86:e00797-17. [PMID: 29378797 PMCID: PMC5865023 DOI: 10.1128/iai.00797-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 01/22/2018] [Indexed: 11/20/2022] Open
Abstract
Malaria in pregnancy can cause serious adverse outcomes for the mother and the fetus. However, little is known about the effects of submicroscopic infections (SMIs) in pregnancy, particularly in areas where Plasmodium falciparum and Plasmodium vivax cocirculate. A cohort of 187 pregnant women living in Puerto Libertador in northwest Colombia was followed longitudinally from recruitment to delivery. Malaria was diagnosed by microscopy, reverse transcription-quantitative PCR (RT-qPCR), and placental histopathology. Gestational age, hemoglobin concentration, VAR2CSA-specific IgG levels, and adhesion-blocking antibodies were measured during pregnancy. Statistical analyses were performed to evaluate the impact of SMIs on birth weight and other delivery outcomes. Twenty-five percent of women (45/180) were positive for SMIs during pregnancy. Forty-seven percent of infections (21/45) were caused by P. falciparum, 33% were caused by P. vivax, and 20% were caused by mixed Plasmodium spp. Mixed infections of P. falciparum and P. vivax were associated with lower gestational age at delivery (P = 0.0033), while other outcomes were normal. Over 60% of women had antibodies to VAR2CSA, and there was no difference in antibody levels between those with and without SMIs. The anti-adhesion function of these antibodies was associated with protection from SMI-related anemia at delivery (P = 0.0086). SMIs occur frequently during pregnancy, and while mixed infections of both P. falciparum and P. vivax were not associated with a decrease in birth weight, they were associated with significant risk of preterm birth. We propose that the lack of adverse delivery outcomes is due to functional VAR2CSA antibodies that can protect pregnant women from SMI-related anemia.
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Affiliation(s)
- Kenneth Gavina
- Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Sedami Gnidehou
- Department of Biology, Campus Saint-Jean, University of Alberta, Edmonton, Alberta, Canada
| | - Eliana Arango
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Chloe Hamel-Martineau
- Department of Biology, Campus Saint-Jean, University of Alberta, Edmonton, Alberta, Canada
| | - Catherine Mitran
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
| | - Olga Agudelo
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Carolina Lopez
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Aisha Karidio
- Department of Biology, Campus Saint-Jean, University of Alberta, Edmonton, Alberta, Canada
| | - Shanna Banman
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
| | - Jaime Carmona-Fonseca
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Ali Salanti
- Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Copenhagen University Hospital, Copenhagen, Denmark
| | | | - Michael Hawkes
- Department of Pediatrics, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Amanda Maestre
- Grupo Salud y Comunidad, Facultad de Medicina, Universidad de Antioquia, Medellín, Colombia
| | - Stephanie K Yanow
- Department of Medical Microbiology and Immunology, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
- School of Public Health, University of Alberta, Edmonton, Alberta, Canada
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