Histology of BMT mice. (A through D) The histology of C57BL/6 mice transplanted with B10.A(4R) BM. One group of mice was injected with allo-restricted CTL while the control group did not receive CTL. (A) Liver from a CTL-treated mouse 3 weeks posttransplant, with no significant inflammation or necrosis. (B) Liver from a control mouse 3 weeks posttransplant, with mild periportal inflammation. Skin from a CTL-treated mouse (C) and a control mouse (D) 3 weeks posttransplant, with no significant inflammation or keratinocyte necrosis. Tissues were also examined at 4, 5, and 6 weeks posttransplant and showed no evidence of GVHD in either CTL-treated or control mice (not shown). (E-H) show the histology of (C57BL/6 × BALB/c) F1 mice, transplanted with BM from littermates. One group of mice was injected with allo-restricted CTL and a control group did not receive CTL. (E) Liver from a CTL-treated mouse 4 weeks posttransplant, with no significant inflammation or necrosis. (F) Liver from control mouse 4 weeks posttransplant, with no significant inflammation and necrosis. Skin from a CTL-treated mouse (G) and a control mouse (H) 4 weeks posttransplant, with no significant inflammation or keratinocyte necrosis. Tissues were also examined at 3 and 5 weeks posttransplant and showed no evidence of GVHD in either CTL-treated or control mice (not shown). (All H&E-stained sections, original magnification × 20.) Sections from colon and stomach also showed no significant inflammation (not shown).