Increased gut injury in B7-H3^−/− vs WT recipients. (A) B6-WT or B7-H3^−/− mice were lethally irradiated and infused with 10⁷ BALB/c NTCD BM and 3 × 10⁶ BALB/c-purified CD25-depleted T cells. On day 21, 16 mg of FITC-dextran was administered orally to mice, and serum levels were measured 4 hours later (n = 4). One experiment was performed. (B) B6-WT or B7-H3^−/− mice were lethally irradiated and infused with 10⁷ BALB/c NTCD BM and 2 × 10⁶ BALB/c-purified T cells. Mice were euthanized on day 21, and intraepithelial lymphocytes were analyzed for total cell numbers (n = 4; P < .05). Intraepithelial lymphocytes were analyzed for Ki-67 as well as effector cytokines IFN-γ, IL-17, and TNF-α (n = 4; P < .05). One experiment was performed. *P < .05; **P < .01.