(A) H&E staining and histological scores of colon and liver tissue sections from 6-month-old mice. Original magnification, ×100. Data are representative of (left) and compiled from (right) 6 mice. Error bars indicate the mean ± SD. *P < 0.05 by two-tailed, unpaired Student’s t test. (B) Overview of DSS-induced chronic colitis model. Mice were administrated 2% DSS for 7 days followed by water and were analyzed up to 4 weeks later. (C) Body weight changes in WT and Cd4^CreTsc1^f/f mice after DSS treatment. Weight loss of individual mice was monitored every 2 days. Data are compiled from three independent experiments with three mice each. Error bars indicate the mean ± SD. *P < 0.05 by two-tailed, unpaired Student’s t test. (D–F) Colon length (D); photograph of representative spleen (SP) and mesenteric lymph nodes (MLNs) (E); H&E staining and histology scores of colon (F). Original magnification, ×100 (F). (G) Flow cytometric analysis of cytokine production (left) and frequencies (right) in colonic lamina propria (cLP) and splenic (SP) CD4⁺ T cells. Cells were obtained from WT and Cd4^CreTsc1^f/f mice 3 weeks after DSS removal (day 28) and restimulated in vitro. Data are compiled from (D) or representative of (E–G) three independent experiments. Each symbol represents an individual mouse (n = 5–6). Error bars indicate the mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001 by two-tailed, unpaired Student’s t test.