FIGURE 6.

IL-17 mediates DSS-induced colitis in the T cell-specific TTP conditional knockout mice. Wild-type and CD4^CreTTP^f/f mice were fed 2.5% DSS water for 5 days and then switched to normal water for additional 4 days. Serum was isolated at day 9 and used to measure IL-17A levels by ELISA (A). Lymphocytes isolated from mesenteric LN at day 9 were analyzed for intracellular cytokine expression by flow cytometry gated as CD4⁺ T cells (B,C). CD4^CreTTP^f/f mice were received 150 mg of IL-17A–specific neutralizing mAb (InVivoMAb anti-mouse IL-17A, clone 17F3; BioXcell) intraperitoneally every other day starting on day 1 after DSS water administration. (D) Average body weight of the mice at indicated time points. (E) At day 9, colons were photographed (insert) and individual colon lengths were measured. (F) Sections of colons were analyzed with hematoxylin and eosin staining. (G) Histological scores of colons collected from the above mice. Data are from four or five mice per group and represented as mean ± SD. *p < 0.05, **p < 0.01, and ***p < 0.001 between groups.