CYTOKINE GENE-EXPRESSION DURING INFECTION OF MICE LACKING CD4 AND/OR CD8 WITH TRYPANOSOMA-CRUZI

The expression of lymphokine genes during infection of virulent (Tulahuen) or mild (CA-I) strains of T. cruzi was studied in mice lacking CD4 and/or CD8 molecules. The increased susceptibility of CD4(-) and CD4(-)CD8(-) mice to infection with CA-I or Tulahuen was paralleled by diminished IFN-gamma mRNA levels. Nitric oxide release and inducible nitric oxide synthase mRNA accumulation by cells from Tulahuen infected CD4(-) mice was also diminished. CD8(-) (but not CD4(-)CD8(-) mice) showed an increased IL-4 and IL-IO mRNA accumulation upon infection with both strains of T. cruzi. A 'T(h)2-like' response (higher IL-4 and IL-10 mRNA to IFN-gamma mRNA ratio), was also observed when cells from noninfected CD8- mice were stimulated with T cell mitogens.