Depletion of Tregs abrogates the protective effect of IL-33 in TNBS-induced colitis. Mice with TNBS-induced colitis were treated with a combination of IL-33 and anti-IL-4 or anti-CD25 antibody; control mice received normal IgG (n = 5 each). (A) The variations in body weight of original weight were recorded on d 4 after TNBS inoculation. (B, C) The histology of tissue sections from TNBS-treated mice with the above treatment was analyzed. Data are mean ± SD; *p < 0.05.