Treg Cells Induced by rSSP4 Derived fromT. cruziAmastigotes Increase Parasitemia in an Experimental Chagas Disease Model

Abstract

Currently, there is a considerable controversy over the participation of Treg cells duringTrypanosoma cruziinfection, the main point being whether these cells play a negative or a positive role. In this work, we found that the adoptive transfer of CD4+CD25+FOXP3+T cells from rSSP4- (a recombinantTrypanosoma cruziamastigote derived protein, previously shown to have immunomodulatory properties on macrophages) immunized BALB/c donors into syngenic recipients simultaneously withT. cruzichallenge reduces cardiac inflammation and prolongs hosts’ survival but increases blood parasitemia and parasite loads in the heart. These CD4+CD25+FOXP3+Treg cells from immunized mice have a relatively TGF-β-dependent suppressive activity on CD4+T cells. Therefore, regulatory CD4+CD25+T cells play a positive role in the development of acuteT. cruziinfection by inducing immunosuppressive activity that controls early cardiac inflammation during acute Chagas disease, prolonging survival, but at the same time promoting parasite growth.