Apoptosis induction in mouse lymphoma cells by anti–third-party Tcm through a nonalloreactive mechanism. CalceinAM-prelabeled murine A20 lymphoma cells (BALB/c origin) were incubated for 16 hours with or without a 5-fold excess of F1 (CB6-H2bd) –derived anti–third-party Tcm or naive CD8 T cells. (A) Numbers of viable Calcein+ lymphoma cells were determined by flow cytometry. Percent killing was calculated as described in “Methods.” Results shown represent average ± SD of 3 independent experiments. *P value < .05 compared with percent killing displayed by naive CD8 T cells. (B-C) Apoptosis was evaluated by using flow cytometry for Calcein and Annexin V+ fluorescence. (B) Representative results demonstrating live A20 lymphoma cells (gating on Calcein+ cells) undergoing apoptosis (Annexin V+) in the presence or absence of anti–third-party Tcm. (C) Quantification of results, shown in panel B, demonstrating apoptosis induction in A20 cells by anti–third-party Tcm. Results represent mean ± SD of 3 independent experiments, each in triplicate. *P value < .05 compared with percent Annexin V+ on A20 cells alone.
