HUMAN-IGG RESPONSES AGAINST THE N-TERMINAL REGION OF THE MEROZOITE SURFACE PROTEIN-1 OF PLASMODIUM-VIVAX

The complete primary structure of the gene encoding the Merozoite Surf ace Protein 1 of Plasmodium vivax (PvMSP-1) revealed the existence of interspecies conserved regions among the analogous proteins of other P lasmodia species. Here, three DNA recombinant clones expressing 50, 20 0 and 500 amino acids from the N-terminal region of the PvMSP-1 protei n were used on ELISA and protein immunoblotting assays to look at the IgG antibody responses of malaria patients from the Brazilian amazon r egion of Rondonia. The results showed the existance of P. vivax and P. falciparum IgG antibodies directed against PvMSP-1 antigenic determin ants expressed in the clones containing the first 200 and the followin g 500 amino acids of the molecule, but not within the one expressing t he most N-terminal 50 amino acids. Interestingly, there was no correla tion between the levels of these IgG antibodies and the previous numbe r of malaria infections.