Benznidazole Treatment during Early-indeterminate Chagas’ Disease Shifted the Cytokine Expression by Innate and Adaptive Immunity Cells toward a Type 1-modulated Immune Profile.

Trypanosoma cruzi-infected children was treated with benznidazole (Bz) during the early-indeterminate disease (E-IND) and the cytokine pattern of innate and adaptive immune compartments were evaluated prior to the treatment and 1 year after it. At first, we observed that the ex vivo cytokine profile of circulating leukocytes from E-IND ( n = 6) resembled the one observed for healthy schoolchildren ( n = 7). Additionally, in vitro stimulation with T. cruzi antigens drove the E-IND cytokine pattern toward a mixed immune profile with higher levels of IFN- γ+, TNF- α+ and IL-4+ NK cells, increased numbers of IFN- γ+, TNF- α+ and IL-10+ CD4+ T cells in addition to enhanced frequency of TNF- α+/IL-4+ CD19+ lymphocytes. Interestingly, upon T. cruzi antigen in vitro stimulation, E-IND CD8+ lymphocytes displayed a selective enhancement of IFN- γ expression, accounting for a global type 1-modulated cytokine microenvironment. A shift toward a type 1-modulated profile was also the hallmark of Bz-treated children (E-INDT). In this context, despite the mixed overall ex vivo cytokine profile observed for NK and CD8+ T cells, increased ability of these leukocytes to produce IFN- γ in response to T. cruzi antigens was reported. Most noteworthy was the IL-10 production evidenced at T lymphocytes, mainly CD4+ cells, as well as B lymphocytes, both ex vivo and upon antigen stimulation. Together, these findings gave evidence that NK cells and CD8+ T lymphocytes are the major sources of IFN- γ, a pivotal cytokine for successful therapeutic response in human Chagas’ disease. Moreover, our data have also brought additional information, pointing out IL-10 production by CD4+ cells and B lymphocytes, as the putative key element for parasite clearance in the absence of deleterious tissue damage. [ABSTRACT FROM AUTHOR]