Il2ra/il21r DKO mice show reduction of Tregs, T-cell hyperactivation, and weight loss and develop colitis similar to il2ra^−/− mice. (A) Body weight of il2ra^−/− (n = 4-11), il21r^−/− (n = 11), DKO (n = 4-10), and WT (n = 5) mice at indicated times. Values indicate percentages of WT. Normalization was done separately for males and females before pooling the data of a group. (B-F) Analysis of the spleen of 5- to 7-week-old mice. Shown is total number of splenocytes after erythrocyte lysis (B), percentages (left panel) and absolute numbers (right panel) of splenic CD4 and CD8 T cells (C), surface expression of CD44 and CD62L on CD4⁺ T cells (D), frequency of CD4⁺ T cells producing IFNγ or IL-17 after 4-hour stimulation with PMA and ionomycin (E), and percentages of FoxP3⁺ CD4⁺ regulatory T cells (F). (G) FACS analysis of lamina propria cells of the colon isolated from 7- to 9-week-old mice as described in “Cell preparation.” Cells were stained with CD4- and CD8-specific antibodies. Shown are dot plots of individual mice representative for the group. (B,C,E,F) Values indicate averages ± SEM of 4-5 mice per group. Data shown are representative of 3 separate experiments. (H) Histopathological scoring of colons of 7- to 10-week old mice (n = 5-8/group) as described in “Histopathology of intestines.” Scores between 0 and 4 indicate no or mild colitis; scores between 5 and 9 indicate moderate colitis; and scores between 10 and 15 indicate severe colitis.