Donor T cells lacking Ezh2 fail to mediate GVHD. (A-B) CD4⁺ and CD8⁺ T cells were isolated from the spleens and lymph nodes of WT and T-KO B6 mice, and the cell lysates were prepared for analysis of Ezh2 expression (A) and histone methylation marks (B). Data are representative of 2 independent experiments. (C-D) Lethally irradiated (8 Gy) BALB/C recipients (H2^d) were transplanted with B6 (H2^b) TCD BM (5 × 10⁶) (○, n = 5) or TCD BM + CD44^lo T cells (ie, 1 × 10⁶ CD4⁺ + 1 × 10⁶ CD8⁺ T cells) that were derived from WT (▪, n = 14) or T-KO (▲, n = 10) B6 mice. (C) Recipient survival and clinical signs were monitored over time (P < .001, ▪ vs ▲). (D) Histologic GVHD score. Tissues were collected at 14 days and later than 17 days after transplantation. (E). Images were obtained with an Olympus BX41 microscope (10/0.3 NA lens, 200× magnification, digital DP70 camera). *P < .05, **P < .01, ***P < .001. Error bars indicate mean ± SD.