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

The expression of lymphokine genes during infection of virulent (Tulah uen) or mild (CA-I) strains of T. cruzi was studied in mice lacking CD 4 and/or CD8 molecules. The increased susceptibility of CD4(-) and CD4 (-)CD8(-) mice to infection with CA-I or Tulahuen was paralleled by di minished IFN-gamma mRNA levels. Nitric oxide release and inducible nit ric oxide synthase mRNA accumulation by cells from Tulahuen infected C D4(-) mice was also diminished. CD8(-) (but not CD4(-)CD8(-) mice) sho wed 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 no ninfected CD8- mice were stimulated with T cell mitogens.