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.
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.
Nogueira
Paulo Afonso
PA
Instituto de Pesquisa em Patologias Tropicais, Porto Velho, Rondônia, Brazil.
Alves
Fabiana Piovesan
FP
Fernandez-Becerra
Carmen
C
Pein
Oliver
O
Santos
Neida Rodrigues
NR
Pereira da Silva
Luiz Hildebrando
LH
Camargo
Erney Plessman
EP
del Portillo
Hernando A
HA
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
D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D020066:Merozoite Surface Protein 1; D010446:Peptide Fragments