Killing of murine lymphoma cells by anti–third-party Tcm is TCR independent and mediated by ICAM-1/LFA-1 interactions and engagement of CD8 molecules. (A) CalceinAM-prelabeled murine A20 lymphoma cells were incubated with or without OT1/Rag^−/− (transgenic TCR)- or F1 (CB6)-derived anti–third-party Tcm for 16 hours at a 5:1 effector/lymphoma cell ratio. Numbers of viable cells were determined by flow cytometry. Percent killing was calculated as described in “Methods.” Results shown represent average ± SD of triplicates in 1 representative experiment out of 2 performed. (B) CalceinAM-labeled murine A20 lymphoma cells were preincubated for 1 hour with or without 50 μg/mL anti–ICAM-1 blocking Ab. F1-derived anti–third-party Tcm were preincubated for 1 hour with or without anti–LFA-1 or anti-CD8 blocking Abs. Following culture for 16 hours at a 5:1 Tcm/lymphoma cell ratio, the number of viable cells was determined by flow cytometry. Results shown represent average ± SD of triplicates in 1 representative experiment out of 3 performed.