FIG. 1.

H. hepaticus does not trigger colitis in IL-10/IL-12 double-deficient mice. WT, IL-10 KO, IL-10/IL-12 KO, IL-12 KO, IL-10/IL-4 KO, and IL-4 KO animals were infected i.g. with H. hepaticus (black bars), and intestinal pathology and cytokine responses were analyzed 5 weeks later. Gray bars represent uninfected controls. (A) Inflammation in the cecum (typhlitis). Bars represent mean histology scores ± SE of four mice/group, with a median value for infected IL-10 KO of 3 (all mice scored as 3) and that of infected IL-10/IL-4 KO of 3.5 (range, 2 to 4). Similar results were observed for the colon, although scores were lower (not shown). (B) IFN-γ levels detected in 72-h supernatants from MLN cells (3 × 10⁶/ml) stimulated with 0.3 μg of SHelAg per ml. Bars represent means ± standard deviations of duplicate ELISA values from MLN cells pooled from 4 mice/group. No IFN-γ was detected from cells cultured in medium alone.