Tcms specifically delete antidonor T cells in vivo. (A-B) Lethally irradiated (10 Gy) C57BL/6 mice received 1 × 105 purified CD8+ 2c cells and 5 × 105 irradiated BALB/c splenocytes. The following day, the mice received a transplant of 1 × 106 C57BL/6-NUDE BM cells or received, in addition, 5 × 106 specific, derived from CB6, or nonspecific, derived from C57BL/6, purified Tcms. Recipients were killed 8 days after transplantation, their spleens were harvested, and the deletion of 2c T cells was monitored by FACS. (A) Representative result demonstrating the level of surviving (7AAD−) 2c cells in the absence (left panel, 2c alone) or presence (right panel, 2c + specific Tcms) of specific Tcms. (B) Quantification of results measuring the inhibition of the 2c cells by specific and nonspecific Tcms. Data represent average ± SD of percentage inhibition from at least 10 animals in each group, pooled from 2 independent experiments. (C-D) Syngeneic BMT model was established as in panels A and B, but 5 × 105 purified CD8+ 2c cells and 2.5 × 106 irradiated BALB/c splenocytes were administrated. Recipients were killed 8 days after transplantation, their spleens were harvested, and FACS analysis of annexin V levels on living (7AAD−) CD8+1B2+ 2c cells was conducted. (C) Representative result demonstrating annexin V levels on 2c cells in the absence (left panel, 2c alone) or presence (right panel, 2c + specific Tcms) of specific Tcms. (D) Quantification of results measuring annexin V levels on the 2c cells after interactions with specific or nonspecific Tcms. Data present average ± SD of percentage annexin V levels in at least 4 animals from each group, in 1 representative experiment of 3 performed. **P < .01; ***P < .001.
