Flagellin alters the regional expression of RegIIIγ in the small intestine. Mice were treated with metronidazole, neomycin and vancomycin (MNV) for 7 days, and on day 5, flagellin was given intraperitoneally at 15 μg per day for 3 days. Tissue from the duodenum, jejunum, and ileum were collected for Western blot analysis and immunohistochemistry. A, Protein extracts were analyzed by Western blotting using RegIIIγ-specific anti-serum. Each lane is a representative mouse from the indicated group. B, RegIIIγ was detected in paraffin-embedded tissue using immunohistochemistry with polyclonal RegIIIγ-specific antiserum. Positive cells were colorized brown (400-fold magnification). The data are representative of two independent experiments (n=6).