IRX4204 reduces intestinal damage and attenuates acute GVHD. (A) Survival, weights, and clinical scores of lethally irradiated BALB/c recipients of 107 B6 non-TCD BM cells, with or without 5 × 106 B6 splenocytes (SPL; n = 15−16 per group). Recipients were treated IP with either vehicle or IRX4204 from day 0 to 56 after transplantation. IRX4204-treated recipients survived longer than vehicle-treated recipients. Data are combined from 2 experiments. (B) Survival, weights, and clinical scores of lethally irradiated B6 recipients of 107 BALB/c NTCD BM cells, with or without 1.5 × 106 CD25- BALB/c T cells (n = 8/group). Recipients were treated with vehicle or IRX4204 from day 0 to 56. IRX4204-treated recipients survived longer than those receiving vehicle. (C) Histopathological scores of BALB/c recipients on day 7 after transplantation (n = 4-6 per group). (D) Plasma FITC-dextran concentration of BALB/c recipients on day 7 after transplantation (n = 7-8/group). *P < .05; **P < .01; ***P < .001; ****P < .0001.