EXPRESSION OF CYTOKINE GENES IN AOTUS MONKEYS IMMUNIZED WITH SYNTHETIC AND RECOMBINANT PLASMODIUM-VIVAX AND PLASMODIUM-FALCIPARUM ANTIGENS

Cytokine responses in human host-protective immunity to malaria have y et to be completely elucidated. No data appear to exist on the cytokin e patterns in non-human primate models immunized with malarial antigen s. Expression of mRNA transcripts of 10 cytokines, the adhesion molecu le ICAM-1 and inducible nitric oxide synthase (iNOS) in peripheral-blo od mononuclear cells (PBMC) from nine Aotus monkeys was analysed by re verse-transcriptase PCR. Five of the monkeys had been immunized with m ultiple-antigen peptides (MAP) of the Plasmodium vivax circumsporozoit e protein and two with constructs of the P. falciparum merozoite surfa ce protein-1 (MSP-1). The other two monkeys served as non-immunized co ntrols. PBMC were cultured for 24 h after stimulation with phytohaemag glutinin mitogen, MAP and MSP-1 antigens. Elevated expression of inter leukin-6 (IL-6), IL-10, IL-12, tumour necrosis factor-alpha (TNF-alpha ), TNF-beta and iNOS was seen in response to the MAP. Monkeys immunize d with either P. falciparum MSP r190L or synthetic 190L peptides expre ssed predominantly the type-1 cytokines (IL-1 beta, IL-12, interferon- gamma, TNF-alpha , TNF-beta) characteristic of splenic, cell-mediated activity with macrophage activation and nitric oxide production.