FIG. 5.

Liver pathology of neonatal IFN-γ^−/−, IFN-γR^−/−, and IL-12p35^−/− mice following i.n. C. muridarum challenge. Groups (n = 3–4) of 1-day-old (A) BALB/c (a–c); or IFN-γ^−/− (d–f); or C57BL/6 (g–i); or IFN-γR^−/− (j–l); or IL-12p35^−/− (m–o) mice were challenged i.n. with 100 IFU of C. muridarum. The mice were euthanized on the indicated days after challenge. The livers were removed, embedded in paraffin, serial horizontal sections cut and stained with H&E. Total magnification 25×. Arrows point toward foci of inflammation. The livers were further scored quantitatively for pathology: (B) IFN-γ^−/− and WT; (C) IFN-γR^−/−, IL-12p35^−/−, and wild-type (WT) animals. Results are expressed as the mean ± SD of the scores in each group. *P ≤ 0.05 between C. muridarum-challenged BALB/c and IFN-γ^−/− mice, C57BL/6 and IFN-γR^−/−, or C57BL/6 and IL-12p35^−/− mice. Results are representative of 2 independent experiments.