Nonimmune Cells Contribute to Crosstalk between Immune Cells and Inflammatory Mediators in the Innate Response to Trypanosoma cruzi Infection

Figure 1

TLR-dependent innate immune responses. T. cruzi-derived components are recognized by TLR2, TLR4, and TLR9, triggering the production of proinflammatory cytokines and microbicidal effectors. Thus, parasite antigens and the cytokines locally released act together to promote the development of protective Th1 response, which lead to parasite growth control. Moreover, TLR2 signaling also has immunoregulatory properties essential to hinder the immune response induced by the parasite. Regarding the T. cruzi entry process, TLR2 but not TLR4 is involved in the activation of Rab-5, fusion of early endosomes, and phagocytosis of trypomastigotes. Furthermore, it is plausible to think that others unexplored TLRs and/or parasite antigens could be involved in the induction of the innate immune responses against T. cruzi.