Reciprocal regulation of Th1- and Th2-cytokine-producing T cells during clearance of parasitemia in Plasmodium falciparum malaria

Flow cytometry for the intracellular detection of T-cell cytokines was perf ormed for 15 Gabonese patients during acute uncomplicated Plasmodium falcip arum malaria, A striking expansion of CD4(+) and CD8(+) T cells producing g amma interferon (IFN-gamma) was found during drug-induced clearance of para sitemia, paralleled by a decrease of interleukin-2 (IL-2) production. The f requency of IL-4- and IL-13-producing CD4(+) cells gradually decreased, whe reas the frequency of T cells producing IL-2(+)-IFN-gamma(+), IL-4(-)-IL-5( +), and IL-4(+)-IL-5(+) cytokines as well as IL-4(+)-IFN-gamma(+) and IL-13 (+)-IFN-gamma(+) cytokines was not significantly altered. The capacity for IL-10 production within the CD4(+) subset increased due to an expansion of both IL-10(+)-IFN-gamma(-) and IL-10(+)-IFN-gamma(+) cytokine-expressing ce lls. Thus, a more pronounced Th2-driven immune response during acute untrea ted P. falciparum infection with a shift towards Th1 responsiveness induced by parasite clearance is suggested.