Supplemental Fig. 3.

Complete ablation of CD4+ Th cells after onset of colitis results in a slight but significant delay in body weight loss but not in complete regeneration of the gut mucosa. Colitis was induced by the adoptive transfer of naive CD45RBhiCD4+ Th cells. CD4+ T lymphocytes were depleted by i.p. injections of 10 mg/kg anti-CD4 (clone GK1.5) when the mice had lost ∼5% of their initial body weight. Lymphocytes were isolated from the inflamed colons of mice at the end of the experiment before the first mouse had lost more than 20% of its initial body weight. Numbers of splenic (A) and colonic (B) CD4+ Th cells are shown. The graph in (C) shows the relative body weight loss of colitic mice over time. (D) Tissue sections from the colons were prepared as described in the figure legend of Supplemental Figure 2. Hematoxylin and eosin staining of colons show infiltration by immune cells, goblet cell loss, hyperplasia and crypt abscesses for both treatment groups. The data shown in (A-C) are from n=6 mice treated with anti-CD4 antibodies and n=6 mice that were treated with PBS (control). Depicted curves in (C) represent the median weight per designated group.