Dissection of the relative contribution of T-cell responses using μMT mice. μMT mice (H-2^b) underwent transplantation with BALB/c (H-2^d) or B10.BR (H-2^k) skin grafts. (A) BMT was performed in presensitized μMT mice 5 to 7 weeks after skin grafting. Recipients were conditioned with 950 to 850 cGy TBI, and 80 to 15 × 10⁶ BMCs were transplanted between 4 and 6 hours after TBI. Sensitized normal B6 mice and naive μMT mice were used as controls. Engraftment was analyzed by flow cytometry 1 month after BMT. (B) Sensitized μMT mice were preconditioned with anti-CD8, anti-CD154, anti-αβ-TCR, or anti-CD4 mAb alone and in combination, followed by 850 cGy TBI, and then underwent transplantation with 30 × 10⁶ or 15 × 10⁶ BMCs matched to the skin graft donor. Chimerism was tested at 1 month and was observed monthly for at least 6 months.