Cytokine Production but Lack of Proliferation in Peripheral Blood Mononuclear Cells from Chronic Chagas ’ Disease Cardiomyopathy Patients in Response

of America Background: Trypanosoma cruzi ribosomal P proteins, P2b and P0, induce high levels of antibodies in patients with chronic Chagas ’ disease Cardiomyopathy (CCC). It is well known that these antibodies alter the beating rate of cardiomyocytes and provoke apoptosis by their interaction with b1-adrenergic and M2-muscarinic cardiac receptors. Based on these findings, we decided to study the cellular immune response to these proteins in CCC patients compared to non-infected individuals. Methodology/Principal findings: We evaluated proliferation, presence of surface activation markers and cytokine production in peripheral blood mononuclear cells (PBMC) stimulated with P2b, the C-terminal portion of P0 (CP0) proteins and T. cruzi lysate from CCC patients predominantly infected with TcVI lineage. PBMC from CCC patients cultured with P2b or CP0 proteins, failed to proliferate and express CD25 and HLA-DR on T cell populations. However, multiplex cytokine assays showed that these antigens triggered higher secretion of IL-10, TNF-a and GM-CSF by PBMC as well as both CD4