Blocking IFN-γ eliminates the promotion of AICD. (A) B6 mice were lethally irradiated and infused with 10⁷ BALB/c NTCD BM and 3 × 10⁶ BALB/c or Tim-3^−/−–purified CD25⁻ T-cells. Recipients of Tim-3^−/− CD25-depleted T cells had a significantly (P = .046) higher survival than those given WT CD25-depleted T cells. Survival plot of IgG control versus αIFN-γ treatment is shown (n = 8/group). (B) B6 mice were lethally irradiated and infused with 10⁷ BALB/c NTCD BM and 3 × 10⁶ BALB/c or Tim-3^−/−–purified CD25⁻ T-cells. Mice were killed on day 7, and splenocytes were analyzed by flow cytometry for annexin V (n = 4) and Ki-67 (n = 5-8; *P < .05). (C) B6 mice were lethally irradiated and infused with 10⁷ BALB/c NTCD BM and 3 × 10⁶ BALB/c or Tim-3^−/−–purified CD25⁻ T cells for IgG control treatment and 1 × 10⁶ BALB/c or Tim-3^−/−–purified CD25⁻ T-cells for αIFN-γ treatment. Mice were killed on day 21, and lamina propria lymphocytes were analyzed for total CD4⁺ and CD8⁺ cell numbers (*P < .05) and total Ki-67 (*P < .05, **P < .01).