Fig. 5

Apoptotis and cell proliferation in the colon of C. jejuni infected mice lacking IL-23p19, IL-22 or IL-18. Conventional wildtype (WT), IL-23p19^−/−, IL-22^−/− and IL-18^−/− mice were perorally infected with C. jejuni strain ATCC 43431 by gavage at days 0, 1 and 2. The average number of colonic epithelial a apoptotic cells (positive for caspase-3, Casp3) and b proliferating cells (positive for Ki67) from at least six high power fields (HPF, 400× magnification) per animal was determined microscopically in immunohistochemically stained colonic paraffin sections at day (d) 14 (black circles) postinfection. Naive (N) mice served as uninfected controls (white circles). Medians (black bars), levels of significance (p values) determined by Mann–Whitney U test, and numbers of analyzed animals (in parentheses) are indicated. Data were pooled from three independent experiments