Effect of anti-gamma-interferon and anti-interleukin-4 administration on the resistance of mice against infection with reticulotropic and myotropic strains of Trypanosoma cruzi.

We studied the effect of in vivo administration of anti-gamma-IFN and anti-IL-4 monoclonal antibodies on the resistance of mice against myotropic and reticulotropic strains of Trypanosoma cruzi. Anti-gamma-IFN treatment augmented the susceptibility of mice when infected with the reticulotropic RA and Tulahuén strains of T. cruzi but did not alter the course of infection with the myotropic CA-I strain of the parasite. In vivo administration of anti-IL-4 enhanced the resistance of mice when infected with either Tulahuén or RA strains but did not affect the course of parasitemia when infected with CA-I. The possible biological relevance of these observations is discussed.