a–l, DQ8-Dd-villin-IL-15tg mice were treated with 200 or 400 μg of depleting anti-CD4 antibody (clone GK1.5) or isotype control (rat IgG2b) twice before and during the course of gluten feeding. a, Experimental scheme. b, c, Representative dot plots showing depletion efficiency in the blood (b) and mesenteric lymph nodes (MLN) (c) of DQ8-Dd-villin-IL-15tg mice. d, The intestinal epithelium was isolated and analysed by flow cytometry. IELs were identified as TCRβ+CD4−CD8+ cells. NKG2D+NKG2− IELs are indicated by absolute number per 100 IECs. (sham, n = 8; gluten + isotype, n = 20, gluten + anti-CD4, n = 12). e–h, Expression of Gzmb (e), Prf1 (f), Rae1 (g) and Qa-1 (h) in the intestinal epithelium as measured by qPCR. Relative expression levels were normalized against the expression levels observed in sham-fed DQ8-Dd-villin-IL-15tg mice (gluten + isotype, n = 12 to 17, gluten + anti-CD4, n = 8). i–l, Serum levels of anti-DGP IgG (i), anti-gliadin IgG2c (j), anti-gliadin IgG (k) and anti-gliadin IgA (l) antibodies were measured by ELISA from serum collected 30 days after gluten feeding (sham, n = 11; gluten + isotype, n = 25-26, gluten + anti-CD4, n = 11). Data are mean values (d, i–l) or mean ± s.e.m. (e–h) from four (b–l) independent experiments. P values determined by ANOVA with Tukey’s multiple comparison test (d, i–l) or unpaired, two-tailed, t-test (e–h).