Distinctive histopathology and modulation of cytokine production during oral and intraperitoneal Trypanosoma cruzi Y strain infection

Acute Chagas disease outbreaks are related to the consumption of food or drink contaminated by triatomine feces, thus making oral infection an important route of transmission. Both vector-borne and oral infections trigger important cardiac manifestations in the host that are related to a dysregulated immune response. The aims of this work were to evaluate possible alterations of lymphocyte CD4+/CD8+ sub-populations, Th1 and Th2 cytokines, nitrite concentrations and cardiac histopathology. One group of male Wistar rats was intraperitoneally infected (I.P.) with 1x10(5) metacyclic trypomastigotes of the T. cruzi Y strain, and another group of Wistar rats was orally infected (O.I.) with 8x10(5) metacyclic trypomastigotes of the same strain. The intraperitoneal infection triggered statistically enhanced parasite and peritoneal macrophage numbers, increased concentrations of NO and IL-12 and elevated cardiac inflammatory foci when compared with the oral infection. However, proliferation of CD4+ and CD8+ T cells were not statistically different for oral and intraperitoneal routes.