title: Antibody responses to surface antigens of Plasmodium falciparum gametocyte-infected erythrocytes and their relation to gametocytaemia.
abstract: An essential element for continuing transmission of Plasmodium falciparum is the availability of mature gametocytes in human peripheral circulation for uptake by mosquitoes. Natural immune responses to circulating gametocytes may play a role in reducing transmission from humans to mosquitoes. Here, antibody recognition of the surface of mature intra-erythrocytic gametocytes produced either by a laboratory-adapted parasite, 3D7, or by a recent clinical isolate of Kenyan origin (HL1204), was evaluated longitudinally in a cohort of Ghanaian school children by flow cytometry. This showed that a proportion of children exhibited antibody responses that recognized gametocyte surface antigens on one or both parasite lines. A subset of the children maintained detectable anti-gametocyte surface antigen (GSA) antibody levels during the 5 week study period. There was indicative evidence that children with anti-GSA antibodies present at enrolment were less likely to have patent gametocytaemia at subsequent visits (odds ratio = 0·29, 95% CI 0·06-1·05; P = 0·034). Our data support the existence of antigens on the surface of gametocyte-infected erythrocytes, but further studies are needed to confirm whether antibodies against them reduce gametocyte carriage. The identification of GSA would allow their evaluation as potential anti-gametocyte vaccine candidates and/or biomarkers for gametocyte carriage.
authors.affiliation: Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: B
authors.initials: B
authors.lastname: Dinko
authors.affiliation: Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: E
authors.initials: E
authors.lastname: King
authors.affiliation: Department of Disease Control, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: G A T
authors.initials: GA
authors.lastname: Targett
authors.affiliation: Department of Immunology and Infection, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: C J
authors.initials: CJ
authors.lastname: Sutherland
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D000917:Antibody Formation; D000954:Antigens, Surface / Q000276:immunology*; D000962:Antimalarials / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004912:Erythrocytes / Q000276:immunology / Q000469:parasitology*; D005260:Female; D005434:Flow Cytometry; D005869:Ghana; D006801:Humans; D007630:Kenya; D008137:Longitudinal Studies; D016778:Malaria, Falciparum / Q000276:immunology* / Q000469:parasitology; D008297:Male; D010963:Plasmodium falciparum / Q000254:growth & development* / Q000276:immunology*; D015800:Protozoan Proteins / Q000276:immunology*
chemical_list: D000913:Antibodies, Protozoan; D000954:Antigens, Surface; D000962:Antimalarials; D015800:Protozoan Proteins
keywords: Plasmodium falciparum; antibodies; antibody responses; gametocytes; surface antigens