FIG 1.

IL-1R^−/− mice are more susceptible to C. rodentium infection than wild-type (WT) mice. (A) WT (n = 12) and IL-1R^−/− (n = 12) mice of B6 background were infected orally with C. rodentium (1 × 10⁹ CFU) and monitored every other day for survival and body weight. Statistical significance for survival rate was determined by Kaplan-Meier analysis. (B) Macroscopic observation and colon measurements were done on postinfection day 10. Each dot represents an individual mouse. (C) Intestinal permeability was measured using FITC-dextran to determine migration from intestine to serum in WT (n = 7) or IL-1R^−/− (n = 10) mice administered PBS or C. rodentium on days 4 and 10. Serum was collected at 4 h, and FITC levels were measured. (D) Representative H&E-stained samples and pathophysiologic scores of colon tissues from WT or IL-1R^−/− mice on postinfection day 10. (E) Double immunostaining shows less E-cadherin (green) and mucin 2 (red) expressed in the colons of IL-1R^−/− mice than in WT mice 4 days after C. rodentium infection. All data are representative of at least three experiments. *, P < 0.05; **, P < 0.01.