The DNAM-1 effects on GVHD are dependent on CD4⁺ T cells. (A) 5 × 10⁶ BM and 2 × 10⁶ or 0.1 × 10⁶ CD3⁺ T cells from B6.WT or B6.DNAM-1^−/− donor mice were transplanted into lethally irradiated bm1 recipients. Survival data (left) and clinical scores (right) with 2 × 10⁶ or 0.1 × 10⁶ T cells are combined from 2 replicate experiments, respectively. 2 × 10⁶ T cells (n = 18 per T-cell–replete group and n = 8 in TCD control). 0.1 × 10⁶ T cells (n = 14 per T-cell–replete group and n = 4 in TCD control). (B) 5 × 10⁶ BM from B6.WT and 1.8 × 10⁶ CD4⁺ T cells from B6.WT or B6.DNAM-1^−/− donor mice were transplanted into lethally irradiated B6C3F1 recipients. P = .0055, B6.DNAM-1^−/− vs B6.WT. Survival data shown are combined from 2 replicate experiments (n = 16 per T-cell–replete group and n = 8 in TCD control).