< i > Plasmodium vivax < /i > AMA1: Implications of distinct haplotypes for immune response

In this study, we analyzed the diversity of AMA1 from BrazilianP.vivax isolates and 19 haplotypes ofP.vivax were found. Among those sequences, 33 nonsynonymous PvAMA1 amino acid sites were identified, whereas 20 of these sites were determined to be located in predicted B-cell epitopes. Nonsynonymous mutations were evaluated for their influence on the immune recognition of these antigens. Two distinct haplotypes, 5 and 16, were expressed and evaluated for reactivity in individuals from northern Brazil. Both PvAMA1 variants were reactive. Moreover, the IgG antibody response to these two PvAMA1 variants was analyzed in an exposed but noninfected population from aP.vivax endemic area. Interestingly, over 40% of this population had antibodies recognizing both variants. These results have implications for the design of a vaccine based on a polymorphic antigen.
Source: PLoS Neglected Tropical Diseases - Category: Tropical Medicine Authors: Source Type: research