Interleukin-10 (IL-10) Counterregulates IL-4-Dependent Effector Mechanisms in Murine Filariasis (original) (raw)

2004, Infection and Immunity

Interleukin-10 (IL-10) was at first described as a Th2-associated cytokine, although more recent reports have shown that immunosuppression applies to both Th1 and Th2 cell responses, e.g., when produced by T regulatory cells. This concept when applied to human filariasis would argue that high parasite loads are associated with IL-10, while bona fide Th2 responses, mediated by IL-4, IL-5, and IL-13, are associated with parasite containment. To prove this relationship in a causal manner, we investigated the roles of IL-4 and IL-10 in a helminth infection model in which mice genetically deficient for IL-4, IL-10, or IL-4 plus IL-10 were infected with the rodent filaria Litomosoides sigmodontis. Compared to C57BL/6 wild-type and IL-10 knockout (KO) mice, IL-4 KO mice remained susceptible, exhibiting a remarkable number of live adult worms. Interestingly however, when the IL-10 gene was knocked out simultaneously with the IL-4 gene, the susceptibility of IL-4 KO mice was reversed. Althou...