Reciprocal Regulation of Th1- and Th2-Cytokine-Producing T Cells during Clearance of Parasitemia in Plasmodium falciparum Malaria

Abstract

ABSTRACT Flow cytometry for the intracellular detection of T-cell cytokines was performed for 15 Gabonese patients during acute uncomplicated Plasmodium falciparum malaria. A striking expansion of CD4 + and CD8 + T cells producing gamma interferon (IFN-γ) was found during drug-induced clearance of parasitemia, paralleled by a decrease of interleukin-2 (IL-2) production. The frequency of IL-4- and IL-13-producing CD4 + cells gradually decreased, whereas the frequency of T cells producing IL-2 + –IFN-γ + , IL-4 − –IL-5 + , and IL-4 + –IL-5 + cytokines as well as IL-4 + –IFN-γ + and IL-13 + –IFN-γ + 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-γ − and IL-10 + –IFN-γ + cytokine-expressing cells. Thus, a more pronounced Th2-driven immune response during acute untreated P. falciparum infection with a shift towards Th1 responsiveness induced by parasite clearance is suggested.