The requirement for NFAT1 for tolerance is CD8 T cell intrinsic. (A,B) K^bD^b double-deficient recipients were treated with 3 Gy TBI/anti-CD154 mAb followed by infusion of 9 × 10⁶ WT or NFAT1^−/− CD8 T cells at the time of T cell–depleted allogeneic BMT (n = 7 animals/group). (A) Incidence of chimerism is depicted at 2, 4, and 6 weeks after BMT for the granulocyte lineage and the B-cell lineage. (B) The level of donor chimerism over time is shown for the granulocyte and the B-cell lineage. (C-D) K^bD^b double-deficient recipients were lethally irradiated (10.25 Gy) and reconstituted with either WT or NFAT1^−/− BM. Two months later, these mice received 3 Gy TBI/anti-CD154 mAb followed by infusion of 9 × 10⁶ WT CD8 T cells at the time of T cell–depleted allogeneic BMT (n = 7 animals/group). (C) Incidence of chimerism is depicted at 2, 4, and 6 weeks After BMT for the granulocyte lineage and the B-cell lineage. (D) The level of donor chimerism over time is shown for the granulocyte and the B-cell lineage.