Expressed var gene repertoire and variant surface antigen diversity in a shrinking Plasmodium falciparum population

Autor(es)

Carlos, Bianca C. ; Fotoran, Wesley L. ; Menezes, Maria J. ; Cabral, Fernanda J. ; Bastos, Marcele F. ; Costa, Fabio T. M. ; Sousa-Neto, Jayme A. ; Ribolla, Paulo E. M. ; Wunderlich, Gerhard ; Ferreira, Marcelo U.

• Tipo de documento: Artigo Científico
• Fonte: Experimental Parasitology; v. 170, p. 90-99, NOV 2016.
• Citações Web of Science: 2

Resumo

The var gene-encoded erythrocyte membrane protein-1 of Plasmodium falciparum (PfEMP-1) is the main variant surface antigen (VSA) expressed on infected erythrocytes. The rate at which antibody responses to VSA expressed by circulating parasites are acquired depends on the size of the local VSA repertoire and the frequency of exposure to new VSA. Because parasites from areas with declining malaria endemicity, such as the Amazon, typically express a restricted PfEMP-1 repertoire, we hypothesized that Amazonians would rapidly acquire antibodies to most locally circulating VSA. Consistent with our expectations, the analysis of 5878 sequence tags expressed by 10 local P. falciparum samples revealed little PfEMP-1 DBL1 alpha domain diversity. Among the most commonly expressed DBL1 alpha types, 45% were shared by two or more independent parasite lines. Nevertheless, Amazonians displayed major gaps in their repertoire of anti-VSA antibodies, although the breadth of anti-VSA antibody responses correlated positively with their cumulative exposure to malaria. We found little antibody cross-reactivity even when testing VSA from related parasites expressing the same dominant DBL1 alpha types. We conclude that variant-specific immunity to P. falciparum VSAs develops slowly despite the relatively restricted PfEMP-1 repertoire found in low-endemicity settings. (C) 2016 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 10/50333-8 - Dinâmica populacional de polimorfismos de Plasmodium vivax na Amazônia rural brasileira
• Beneficiário: Marcelo Urbano Ferreira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 09/53702-7 - Antigenos variantes de superficie de hemaceas infectadas por plasmodium falciparum na amazonia brasileira: aderencia a receptores endotelio vascular (cd36 e icam-1) e reconhecimento por anticorpos.
• Beneficiário: Bianca Cechetto Carlos
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 09/17114-3 - Resposta humoral contra antígenos da superfície da hemácia infectada com Plasmodium falciparum: parâmetros de proteção em infecções naturais na Amazônia
• Beneficiário: Gerhard Wunderlich
• Modalidade de apoio: Auxílio à Pesquisa - Regular