Program and abstract of the 45th annual meeting of the American Society of Tropical Medicine and Hygiene

Abstract

To investigate the potential influence of antigen (Ag) presentation on the immune response to MSP1 19, the 19 kDa C-terminal domain of the #Plasmodium falciparum MSP1 Ag, 3 recombinant MSP 19 Ags expressed in baculovirus, #E. coli and #Saccharomyces cerevisiae were used to stimulate in vitro peripheral blood mononuclear cells (PBMCS) from #P. falciparum immune adults with no recent history of clinical malaria. Donors were recruited in 2 senegalese villages (Dielmo and Ndiop), where malaria transmission is perennial and seasonal, respectively. Each PBMC preparation was stimulated with a range of concentrations of the 3 recombinant Ags (cleaved from carrier molecules when appropriate). Most subjects responded to at least 1 recombinant Ag (SI > 3 in 8/10 at Dielmo and 14/15 at Ndiop). The dose-dependent response to #Saccharomyces cerevisiae MSP1 19 was similar in both villages. In contrast, there was a 10-fold difference in the optimal concentration of the #E. coli product between the two villages. Both the optimal dose and the concentration-dependence of the simulation by the baculovirus recombinant protein differed in each setting. These studies show that the 3 recombinant antigens differ in their capacity to stimulate lymphocyte proliferation, suggesting that protein structure (folding and/or glycosylation) affecting Ag processing, is critical. Futhermore, these data suggest that the malaria transmission pattern influences the immune response to the various MSP1 19 recombinants. (Résumé d'auteur