Cdd CD8⁺T cells cause acute GVHD. The bm1 cells were transplanted from wt B6 (•, n = 11) or cdd B6 (▴, n = 6) donors as in Figure 1. B6 syngeneic BM transplant recipients (○,n = 9) served as no-GVHD controls. (A) Survival. (B) Histology. At 30 days after BMT, liver, intestine (bottom column [•], small intestine; upper column, large intestine), and skin were harvested and scored semiquantitatively (n = 4/group). B6 → B6 (syn; □), wt B6 → bm1 (wt; ▦), and cdd B6 → bm1 (cdd; ▩ ). (C) Serum cytokines. Mice received transplants of wt, pfp^–/–, gld, or cdd as in Figure 1 and were killed on day 30 (n = 3 mice/group). Serum was harvested and analyzed for TNF α and IFN γ by ELISA (pg/mL). Each graph represents 1 of 3 similar experiments. Data represent mean ± SD. wt versus cdd, *P < .05 by Mann-Whitney U test.