Treatment of mouse GVHD by antagonistic anti–HVEM mAb. (A) BDF1 mice (n = 5 in each group) were exposed to lethal-dose irradiation (12 Gy) followed by intravenous injection of 5 × 106 T cell–depleted B6 BM cells alone (○) or together with 3 × 106 B6 T cells. In the groups receiving T-cell transfer, the mice were treated intraperitoneally with 150 μg LBH1 (•) or control hamster IgG (□) on days 0, 3, and 6 after BM transfer. The survival of recipient mice was monitored daily. *P = .03. (B) B6 mice (n = 7 in each group) were exposed to lethal-dose irradiation (10 Gy) followed by intravenous injection of 4 × 106 T cell–depleted C3H.SW BM cells alone (○) or together with 3 × 107 C3H.SW spleen cells. In groups with spleen cell transfer, the mice were treated intraperitoneally with 100 μg LBH1 (▴) or control Ig (▪) on days 0, 5, 10, 15, 20, and 25. The survival of recipient mice was monitored daily. *P = .003. (C) On day 60 after BM transfer under the same conditions described for panel B, the percentage of body weight compared to the original (pre-BM transfer) and GVHD clinical scores of recipient mice treated with either LBH1 (open bar) or control IgG (filled bar) are shown as average ± SD. At the same time, gross appearance of recipient mice (D) and pathological analyses of liver, skin, and large intestine by H&E staining (magnification, 200 ×/400 × in liver and 200 × in others) (E) are shown. In the sections of colon, apoptotic epithelial cells are indicated by white arrowheads. (F) Spleen cells from the recipient mice surviving GVHD at least 40 days following injections of LBH1 or control Ig were examined for the expression of Ly9.1 and CD3 or B220 by flow cytometry. Percentages of cells in each quadrant are indicated. Representative data from 2 independent series of experiments are shown.
