title: A reduced risk of infection with Plasmodium vivax and clinical protection against malaria are associated with antibodies against the N terminus but not the C terminus of merozoite surface protein 1.
abstract: Progress towards the development of a malaria vaccine against Plasmodium vivax, the most widely distributed human malaria parasite, will require a better understanding of the immune responses that confer clinical protection to patients in regions where malaria is endemic. The occurrence of clinical protection in P. vivax malaria in Brazil was first reported among residents of the riverine community of Portuchuelo, in Rondônia, western Amazon. We thus analyzed immune sera from this same human population to determine if naturally acquired humoral immune responses against the merozoite surface protein 1 of P. vivax, PvMSP1, could be associated with reduced risk of infection and/or clinical protection. Our results demonstrated that this association could be established with anti-PvMSP1 antibodies predominantly of the immunoglobulin G3 subclass directed against the N terminus but not against the C terminus, in spite of the latter being more immunogenic and capable of natural boosting. This is the first report of a prospective study of P. vivax malaria demonstrating an association of reduced risk of infection and clinical protection with antibodies against an antigen of this parasite.
authors.affiliation: Instituto de Pesquisa em Patologias Tropicais, Porto Velho, Rondônia, Brazil.
authors.forename: Paulo Afonso
authors.initials: PA
authors.lastname: Nogueira
authors.forename: Fabiana Piovesan
authors.initials: FP
authors.lastname: Alves
authors.forename: Carmen
authors.initials: C
authors.lastname: Fernandez-Becerra
authors.forename: Oliver
authors.initials: O
authors.lastname: Pein
authors.forename: Neida Rodrigues
authors.initials: NR
authors.lastname: Santos
authors.forename: Luiz Hildebrando
authors.initials: LH
authors.lastname: Pereira da Silva
authors.forename: Erney Plessman
authors.initials: EP
authors.lastname: Camargo
authors.forename: Hernando A
authors.initials: HA
authors.lastname: del Portillo
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007074:Immunoglobulin G / Q000145:classification; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D016780:Malaria, Vivax / Q000517:prevention & control*; D020066:Merozoite Surface Protein 1 / Q000737:chemistry / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology*; D010966:Plasmodium vivax / Q000276:immunology*; D011446:Prospective Studies; D013997:Time Factors
chemical_list: D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D020066:Merozoite Surface Protein 1; D010446:Peptide Fragments