Lethally irradiated BALB/c mice were injected with TCD-BM from B6 mice. Syngeneic BMT (both BM and recipients from B6 mice) were used as controls. Both syngeneic and allo-BMT recipients were treated with rIL-7/HGFβ (15 μg) or PBS at 2-day intervals from days 1 to 26 after BMT. (A) weights and (B) histopathological analysis of signs of GVHD in liver, small bowel (SB) and large bowel (LB) were conducted on day 75 after BMT. (C) Splenocytes harvested from the allo-BMT recipients were used as effector cells for MLRs. Splenocytes from normal non-BMT B6 mice were used as controls. The effector cells were cultured with irradiated splenocytes (as stimulators) from normal non-BMT BALB/c, B6, and CBA mice, respectively. Cell proliferation was determined by BrdU incorporation. Mean OD in MLRs/OD in spontaneous proliferation with splenocytes from all-BMT recipients or normal B6 mice as effectors and splenocytes from BALB/c, B6, and CBA mice as stimulators were 0.21/0.20, 0.20/0.20, 2.97/0.21, as well as 2.95/0.21, 0.21/0.20, and 3.15/0.22, respectively. Data are shown as stimulation index. (A-C) The data are representative of 2 independent experiments of 5 mice each group.