A Role for Peroxisome Proliferator-Activated Receptors in the Immunopathology of Schistosomiasis?

Figure 1

Summary of possible interactions in schistosomiasis with PPARs. This figure displays the possible pathways in which PPARs could be involved in schistosomiasis. PPARs could be involved in immune regulation, as they are associated in generation of a Th2 response. PPARβγ/α both cause downregulation of Th1 cytokines and promote IL-4/-13 production. PPARs have a role in the alternate activation of macrophages where PPARγ/α have been demonstrated to be essential for this process. In schistosomiasis, AAMΦs have a protective effect and a role in Th2 biasing. Schistosomes could interact with this activation indirectly via induction of IL-4/-13 production and directly by the breakdown products of hemozoin, which can interact with PPARγ/α. In terms of pathology, the PPARs could interact with the transdifferentiation process of HSCs into fibrogenic myofibroblasts. They could limit this process by inhibiting transdifferentiation associated with increased PPARγ, whereas PPARα would be associated with generation of the fibrogenic myofibroblast.