IL-12 and TNF-alpha production by dendritic cells stimulated with Schistosoma mansoni schistosomula tegument is TLR4- and MyD88-dependent.

Schistosoma mansoni schistosomula are the most susceptible parasite life stage to host immune system attack. Complex host-parasite interactions take place on Schistosoma tegument, which is a unique double membrane structure involved in nutrition and immune evasion. Herein, we have demonstrated that schistosomula tegument (Smteg) activates Dendritic cells to produce IL-12p40, TNF-alpha and also to up-regulate the co-stimulatory molecules CD40 and CD86. Moreover, using DCs derived from MyD88-, TLR2-, TLR4- and TLR9-deficient mice we have shown that the ability of Smteg to activate DCs to produce IL-12 and TNF-alpha involves TLR4/Smteg interaction and MyD88 signaling pathway. Finally, our findings lead us to conclude that TLR4 is a key receptor involved in Smteg induction of pro-inflammatory cytokines.