Susceptibility to malaria in fulani, Bariba, Otamari and gando individuals living in sympatry in Benin: Role of opsonizing antibodies to Plasmodium falciparum merozoites
Department for Congenital Disorders, Statens Serum Institut, Denmark; Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen, Denmark
Asier Garcia-Senosiain
Department for Congenital Disorders, Statens Serum Institut, Denmark; Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen, Denmark
Benoît Henry
Université Paris Cité, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, Paris, France
Célia Dechavanne
Université Paris Cité, IRD, UMR261, MERIT, F-75006 Paris, France
André Garcia
Université Paris Cité, IRD, UMR261, MERIT, F-75006 Paris, France
Pierre Buffet
Université Paris Cité, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, Paris, France; Institut Pasteur, Paris, France
Audrey Sabbagh
Université Paris Cité, IRD, UMR261, MERIT, F-75006 Paris, France
Florence Migot-Nabias
Université Paris Cité, IRD, UMR261, MERIT, F-75006 Paris, France
Michael Theisen
Department for Congenital Disorders, Statens Serum Institut, Denmark; Centre for Medical Parasitology, Department of International Health, Immunology and Microbiology, University of Copenhagen, Denmark
David Courtin
Université Paris Cité, IRD, UMR261, MERIT, F-75006 Paris, France
Objectives: Fulani in Africa are known to be less susceptible to Plasmodium falciparum (Pf) malaria. This study explored a potential involvement of antibody-mediated merozoite phagocytosis mechanism in this natural protection against malaria. Methods: Before the start of the malaria transmission season (MTS) in Benin, the functionality of antibodies against Pf merozoites was determined by the opsonic phagocytosis (OP) assay in plasma samples from Fulani, Bariba, Otamari and Gando groups. These individuals were actively followed-up for malaria detection from the beginning to the end of MTS. Anti-GLURP Immunoglobulin G antibody quantification, malaria Rapid Diagnostic Test (RDT) and spleen palpation were performed before and after MTS. Results: In Bariba, Otamari and Gando, but not in Fulani, plasma from adults promoted higher levels of OP than the children (P = 0.003; P = 0.012; P = 0.031 and P = 0.122). A high proportion of Fulani children had higher OP and anti-GLURP (P < 0.0001) antibody levels as compared to non-Fulani children; whereas this was not observed for Fulani adults (P = 0.223). High OP levels before MTS were significantly related to negative RDT after MTS (P = 0.011). Conclusion: Our results highlight the ability of opsonizing antibodies to potentially enhance natural protection of young Fulani individuals against Pf malaria in Benin.
