IL-7 administration does not diminish GVL activity.

(A) Lethally irradiated (1300 cGy) (B6 × C3H)F1 recipients were transplanted with B6 TCD BM cells (5 × 10⁶) as described in Table 1. Recipients received 32Dp210 CML cells (5000) on day 0 and osmotic minipumps were used for continuous subcutaneous administration of 1 μg/d IL-7 or PBS (control) from day −1 to day +13. Each group contained 8 animals. (B) All (B6 × C3H)F1 recipients were transplanted and treated with IL-7/PBS as described in panel A with the addition of B6 splenic T cells (0.5 × 10⁶) on day 0. ○ indicates PBS; ■, IL-7. The cause of death (GVHD or leukemia) of all animals that died during the experiments shown in panel B was determined by necropsy and is shown in panel C.indicates tumor;, GVHD. Survival is depicted as a Kaplan-Meier curve and each group contained 14 animals.