CYTOKINE MESSENGER-RNA PROFILE OF PERIPHERAL-BLOOD MONONUCLEAR-CELLS ISOLATED FROM INDIVIDUALS WITH TRYPANOSOMA-CRUZI CHRONIC INFECTION

Characterization of immunologic activities during chronic infection wi th Trypanosoma cruzi is critical for understanding the;dynamics of hum an Chagas' disease. Since cytokine production is mainly regulated by t ranscription and mRNA stability, quantitative RT-PCR analysis gives an accurate picture of the influences of disease on cytokine profile; Us ing RT-PCR, the authors analysed the levels of message expression for several cytokines in peripheral blood mononuclear cells (PBMC) freshly isolated from chagasic patients (CP) and non-infected individuals (NI ), and in in vitro-stimulated PBMC from CP. Ex vivo analysis showed th at mean levels of expression of IL-5, IL-10, IL-13 and IFN gamma were dramatically increased in PBMC from CP, compared to NI. The levels of IL-2 and IL-4 were not significantly different between groups. Analysi s of cytokine mRNA production after in vitro culture with parasite-der ived antigens (EPI or TRP) or anti-epimastigote antibodies (Id) showed that these two classes of stimuli induced distinct cytokine responses . While EPI or TRP induced higher production of IFN gamma specific mes sage and low IL-10, anti-Id cells produced higher levels of IL-10 and low IFN gamma. The simultaneous presence of antigenic and antibody sti mulation in the host during the chronic phase of Chagas' disease could explain the existence of both inflammatory and anti-inflammatory cell ular reactivity detected in most patients.