Engraftment of B6.SJL marrow cells into 100-cGy–irradiated, spleen pretreated BALB/c hosts injected with higher levels of anti-CD40 ligand mAb.

BALB/c hosts were infused with 10 million B6.SJL spleen cells on day −10 and administered 1.6 or 3.2 mg of anti-CD40 ligand (L) mAb on days −10, −7, −3, 0, and +3. As preparation for transplantation on day 0 BALB/c mice were exposed to 100 cGy WBI and infused with 40 million B6.SJL marrow cells. Engraftment of donor cells was determined as percentage (%) CD45.1 cells in peripheral blood at 3 to 15 weeks after transplantation. There were 5 mice per group.