Notch blockade in mature T cells prevents sclerodermatous cGVHD. BALB/c mice were lethally irradiated (8-8.5 Gy), followed by transplantation of B10.D2-Thy1.2 TCD BM (light green circle), TCD BM with 12 × 10⁶ B10.D2-Thy1.1 WT splenocytes (red circle), or 12 × 10⁶ B10.D2-DNMAML splenocytes (blue circle), followed by monitoring with systemic or skin-specific clinical GVHD scores. B10.D2-DNMAML T cells cannot respond to canonical Notch signals. (A) Mean systemic clinical GVHD scores. *P < .01 (WT vs DNMAML T cells and WT T cells vs TCD BM only; 1-way ANOVA). (B) Mean skin-specific clinical GVHD scores; *P < .01 (WT vs DNMAML T cells and WT T cells vs TCD BM only; 1-way ANOVA). (C) Overall survival; *P < .001 (WT vs DNMAML T cells and WT T cells vs TCD BM only; log-rank test). n = 20 mice/group, pooled from 4 experiments. (D) Representative images of recipient mice on day 35 show absence of Scl-cGVHD features in TCD BM and DNMAML T-cell recipients. (E) Histopathological assessment of dermal thickness, a hallmark of skin cGVHD (n = 14, 3 experiments). *P < .01 (1-way ANOVA). (F) Flow cytometric assessment of inflammatory cytokine production and FoxP3 expression in donor-derived spleen T cells (day 6). Representative contour plots (left). Numbers indicate the percentage of events falling within indicated rectangular gates. Cumulative quantification (right) (n = 10 mice/group, from 3 experiments). *P < .001 (2-tailed unpaired Student t test). IFN, interferon; IL, interleukin; TNF, tumor necrosis factor.