Plasmodium falciparum: sequence diversity and antibody recognition of the Merozoite surface protein-2 (MSP-2) in Brazilian Amazonia.
The merozoite surface protein-2 (MSP-2) of Plasmodium falciparum comprises repeats flanked by dimorphic domains defining the allelic families FC27 and IC1. Here, we examined sequence diversity at the msp-2 locus in Brazil and its impact on MSP-2 antibody recognition by local patients. Only 25 unique partial sequences of msp-2 were found in 61 isolates examined. The finding of identical msp-2 sequences in unrelated parasites, collected 6-13 years apart, suggests that no major directional selection is exerted by variant-specific immunity in this malaria-endemic area. To examine antibody cross-reactivity, recombinant polypeptides derived from locally prevalent and foreign MSP-2 variants were used in ELISA. Foreign IC1-type variants, such as 3D7 (currently tested for human vaccination), were less frequently recognized than FC27-type and local IC1-type variants. Antibodies discriminated between local and foreign IC1-type variants, but cross-recognized structurally different local IC1-type variants. The use of evolutionary models of MSP-2 is suggested to design vaccines that minimize differences between local parasites and vaccine antigens.
Tonon
Angela Pedroso
AP
Departamento de Parasitologia, Instituto de Ciências Biomédicas da Universidade de São Paulo, Av. Prof. Lineu Prestes 1374, Cidade Universitária, 05508-900 São Paulo, Brazil.
Hoffmann
Erika Hellena Esther
EH
Silveira
Lucimeire Antonelli da
LA
Ribeiro
Adálton Guimarães
AG
Gonçalves
Clara Rosa da Silva
CR
Ribolla
Paulo Eduardo Martins
PE
Wunderlich
Gerhard
G
Ferreira
Marcelo Urbano
MU
D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood / Q000276:immunology*; D000953:Antigens, Protozoan / Q000737:chemistry / Q000276:immunology*; D001483:Base Sequence; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D007223:Infant; D016778:Malaria, Falciparum / Q000453:epidemiology / Q000469:parasitology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000235:genetics / Q000276:immunology*; D015800:Protozoan Proteins / Q000737:chemistry / Q000276:immunology*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D015800:Protozoan Proteins; C065974:merozoite surface protein 2, Plasmodium