Wnt Signalling Orchestrates the Immune Response and Cardiac Damage DuringTrypanosoma cruziInfection

Abstract

Chagas' cardiomyopathy is the consequence of a compromised electrical and mechanical cardiac function, with parasite persistence, unbalanced inflammation and pathological tissue remodelling, being intricately related to the myocardial aggression and the impaired function. Recent studies have shown that Wnt signalling pathways, which are important for developmental processes, play a critical role in the pathogenesis of cardiac and vascular diseases. In addition, we have reported that Trypanosoma cruzi infection activates Wnt signalling pathways in macrophages to promote their intracellular replication, with treatment of mice with IWP-L6 (an inhibitor of the O-acyl-transferase, PORCN, responsible for the post-translational modifications necessary for Wnt proteins secretion) being able to diminish parasitaemia and tissue parasitism. Therefore, Wnt signalling may contribute to the development of Chagas' cardiomyopathy. In this work we have evaluated the effectiveness of Wnt secretion inhibition to control the parasite replication, modulate the adaptive immune response, and prevent the development of cardiac lesions in an experimental model of chronic Chagas disease. The IWP-L6 treatment, administered to T. cruzi infected BALB/c mice in a time window during the acute phase of the infection, was able to control the parasitaemia and heart parasitism together with the amelioration of the electrical, mechanical and histopathological cardiac alterations observed in chronically infected mice. Moreover, we demonstrated that during the acute phase of the infection Wnt signalling activation contributes to promote specific Th2-type immune response and to maintain the suppressive activity of Treg cells. Our data provide evidence that inhibition of Wnt signalling during the acute phase of T. cruzi infection controls the parasite replication, inhibits the development of parasite-prone and fibrosis-prone Th2-type immune response and prevents the development of cardiac lesions characteristics of chronic Chagas disease. Our study suggests that Wnt signalling pathway might be a potential target to prevent the development of T. cruzi-induced cardiomyopathy.