Inhibitory activity of IL-6 on malaria hepatic stages.

Addition of recombinant interleukin-6 (IL-6) to Plasmodium yoelii hepatic cultures resulted in a specific dose-dependent inhibition of parasite development. Time course experiments showed that, without any direct effect on free sporozoites, IL-6 exerts its action during both the early phase of infection and during the subsequent maturation of the schizonts. Elicitation of the oxidative burst appears to be one mechanism by which IL-6 interferes with the development of hepatic phase. Catalase and superoxide dismutase, two scavengers of hydrogen peroxide and superoxide anions, reversed the IL-6 mediated parasiticidal activity.