Immunization of Saimiri sciureus monkeys with Plasmodium falciparum merezoite surface protein-3 and glutamate-rich protein suggests that protection is related to antibody levels

Abstract

The immunogenicity and protective efficacy of various antigen-adjuvant fomulations derived either from the merezoite-surface protein-3(MSP-3)or the glutamate-richprotein (GLURP) of Plasmodium falciparum were evaluated in Saimiri sciureus monkeys. These Proteins were selected for immunogenicity studies based primarily on their capacity of inducing an antibody-dependent cellular inhibition effect on parasite growth. Some of the S.sciureus monkeys immunized with MSP-3 212-380 - AS02 or GLURP 27-500 - alum were able to fully or partially control parasitaemia upon an experimental P. falciparum [Falciparum Uganda Palo Alto (FUP-SP) stain] blodd-stage infection, and thisprotection was related to the prechallenge antibody titres induced. The data are indicative that MSP-3 and GLURP can induce protective immunity against an experimental P. falciparum infection usig adjuvants that are aceptable for human use and this sholud trigger further studies with those new antigens.