Increase in the expression of CD4 + CD25+ lymphocytic T cells in the indeterminate clinical form of human Chagas disease after stimulation with recombinant antigens of Trypanosoma cruzi.

Abstract

Regulatory T cells are involved in the clinical course of chronic Chagas disease, possibly because they exercise a control in the patient's inflammatory response to Trypanosoma cruzi. This study analyzed the levels of CD4 + CD25+ T cells in chronic Chagas disease patients after in vitro stimulation of the peripheral blood mononuclear cells with CRA (Cytoplasmic Repetitive Antigen) or FRA (Flagellar Repetitive Antigen) T. cruzi antigens. Groups of patients with the cardiac form and indeterminate form; and non-infected individuals, were selected. The CD4 + CD25+ T lymphocyte population, as well as the FoxP3 expression and the IL10 production, were evaluated by flow cytometry after stimulation with CRA or FRA. The IND group presented higher levels of CD4 + CD25+ T cells than the CARD group. However, there was no evidence of a relationship between FoxP3 and IL10 with any of the chronic forms. Our results suggest the possible involvement of CD4 + CD25+ T cells specific to CRA and FRA in controlling the progression of clinical outcomes. Though, further studies are needed to define which mechanisms activate regulatory T cells and lead to pathology control in chronic human Chagas disease.