Anti-CD8 mAb treatment decreases the minimum TBI dose required for allogeneic engraftment in NOD mice, while anti-CD4 impairs conditioning. (A) Mice were preconditioned with anti-CD8 mAb on day -3, and/or anti-CD4 mAb on day -2 relative to the TBI. Recipients received transplants of 30 × 106 B10.BR BMCs 4 to 6 hours after TBI. A minimum of 10 animals per group in at least 3 separate experiments is shown. (B) Percentage of recipients with engraftment at 28 days. ○ indicates no mAb; •, anti-CD8; □, anti-CD4; and ▪, anti-CD8 plus anti-CD4. (C) The percentage of donor cell chimerism in the mice that engrafted with anti-CD8 preconditioning 1 and 6 months after transplantation. ○ indicates recipients of 700 cGy TBI; ▪, 600 cGy; ▵, 550 cGy. Error bars indicate ± SD.
