C. rodentium infection causes loss of barrier function and enterocyte apoptosis in IKKβ(EE)^IEC mice. (a) Lysates of small intestinal WT and IKKβ(EE)^IEC enterocytes prepared 6 d after C. rodentium challenge were analyzed for expression and phosphorylation of the indicated proteins by immunoblotting. Representative of four experiments. (b) C. rodentium counts in stool and liver were determined by CFU assay. Results are means ± SEM (n = 8). *, P < 0.05 versus WT. Data are representative of three independent experiments. (c) WT and IKKβ(EE)^IEC mice were analyzed 14 d after C. rodentium infection. Colon sections were stained with either H&E (top) or by an in situ TUNEL assay (bottom). Representative of three experiments. (d) Indicated mouse strains were analyzed 14 d after C. rodentium infection. Colon sections were H&E stained. Arrows point at apoptotic cells. Representative of two experiments.