In vivo depletion of CD25⁺ T cells in IL-7^–/– and wild-type mice. (A) IL-7^–/– mice were depleted of CD25⁺ T cells by 10 daily injections of anti-CD25 antibodies. (Top panels) Flow cytometric analysis of CD25 and Foxp3 expression in gated CD4 cells in the spleen of depleted mice. (Bottom panels) Histologic analysis of the colon of mice at the indicated times before or after depletion. (B) B6 mice were depleted of CD25⁺ T cells by 10 daily injections of anti-CD25 antibodies. (Top panels) Flow cytometric analysis of CD25 and Foxp3 expression in gated CD4 cells in the spleen of depleted mice. (Bottom panels) Histologic analysis of the colon of mice at the indicated times before or after depletion.