IL-7 administration does not aggravate GVHD mortality in allogeneic BMT recipients.

(A) Lethally irradiated (1300 cGy) CBA/J recipients (3 months old) received transplants with B10.BR TCD BM cells (5 × 10⁶) + splenic T cells (0.5 × 10⁶). Osmotic minipumps were used for continuous subcutaneous administration of 1 μg/d IL-7 or PBS (control) from day −1 to +13. (B) All CBA/J recipients (3 months old) underwent transplantation as described in panel A. Osmotic minipumps were used for continuous subcutaneous administration of 1 μg/d IL-7 or PBS (control) from day +14 to day +28. (C) Lethally irradiated (1300 cGy) (B6 × C3H)F1 recipients underwent transplantation with B6 TCD BM cells (5 × 10⁶) + splenic T cells (2 × 10⁶). Osmotic minipumps were used for continuous subcutaneous administration of 1 μg/d IL-7 or PBS (control) from day −1 to +13. Survival is depicted as a Kaplan-Meier curve. Each group contained 8 animals. ○ indicates PBS; ■, IL-7.