Modulation of chemokine production and inflammatory responses in interferon-γ- and tumor necrosis factor-R1-deficient mice during Trypanosoma cruzi infection

Infection with Trypanosoma cruzi causes a strong inflammatory reaction at the inoculation site and, later, in the myocardium, The present study investigates the role of cytokines as modulators of T. cruzi-induced chemokine expression in vivo and in vitro, In macrophage cultures, although the stimulation with interferon (IFN)-gamma increases the expression of IP-10, it blocks KC expression, Tumor necrosis factor (TNF)-alpha, on the other hand, potentiates KC, IP-10, macrophage inflammatory protein-1 alpha, and JE/monocyte chemotatic protein-1 expression. Interleukin-10 and transforming growth factor-beta inhibited almost all chemokines tested. The role of IFN-gamma and TNF-alpha in chemokine modulation during infection was investigated in T, cruzi-infected IFN-gamma -deficient (GKO) or TNF-R1/p55-deficient (p55-/-) mice. The expression of chemokines detected in the inoculation site correlated with the infiltrating cell type observed. Although GKO mice had a delayed and intense neutrophilic infiltrate correlating with the expression of KC and macrophage inflammatory protein-2, none of the above was observed in p55-/- mice, The detection of infiltrating T cells, Mig, and IP-10 in the myocardium was observed in wild-type and p55-/-, but not in GKO mice. Together, these results suggest that the regulatory roles of IFN-gamma and TNF-alpha on chemokine expression may play a crucial role in the modulation of the inflammatory response during T, cruzi infection and mediate resistance to infection.