Interleukin-17 producing T helper cells are increased during natural Plasmodium vivax infection

In the current study we showed that uncomplicated acute vivax malaria induce a significant expansion of Th17 cells associated to a pro-inflammatory cytokine profile. [Display omitted] ► Circulating Th17 cell number was evaluated during acute vivax malaria infection. ► Correlation between Th17 cell number and cytokine production was assessed. ► We showed the expansion of Th17 cells during natural malaria vivax infection. ► Th17 cell number was correlated with regulatory cytokine profile. ► Correlation between Th17 cell number and morbidity or parasitemia were not detected. Recent evidences have demonstrated the importance of Th17 cells in host defense against infectious diseases. However, little is known about their role in parasitic infections. Here, we showed that uncomplicated acute vivax malaria induce a significant expansion of IL-17-producing CD4+ T cells associated to a pro-inflammatory cytokine profile. Furthermore, we demonstrated a correlation between numbers of IL-17+CD4+ T cells and circulating CD4+ T-cells producing IFN-γ, IL-10 and TGF-β. Finally, correlations between number of these cells and morbidity or parasitemia were not detected. Further studies are underway to investigate whether IL-17-producing CD4+ T cells are critically involved in the immunity against Plasmodium vivax infection.