Anti-IL-7Rα antibody treatment reduced IBD scores and histopathology of H . bilis -induced colitis in Mdr1a−/−mice. Five-week-old male Mdr1a−/− mice were treated IP twice weekly with 500 μg or 50 μg of anti-IL-7Rα M595, or 500 μg of isotype control antibody one week prior to oral gavage with H. bilis (Hb, 2 × 107 CFU administered once) or broth (uninfected controls) and then treated twice weekly throughout the duration of the study for 9 weeks post-infection. (A) Histopathological IBD scores from colon. Cecum and colon IBD scores were based on severity of mucosal epithelial changes, degree of inflammation and extent of lesions . (B) Gross and representative H&E-stained histological sections from uninfected control (isotype broth), infected control (isotype Hb) and anti-IL-7Rα M595/500 and anti-IL-7Rα M595/50-treated Hb-infected mice. Histological images, original magnification 10X. (C) Percent change in weight is shown for mice 1 week prior to infection through 4 weeks post infection (last time point in which all mice were alive). ANOVA with square root transformation followed by Tukey’s post-test (a). *p < 0.05, **p < 0.001, ***p <0.0001.