Cytotoxicity of thymocytes and splenocytes from control and ZAP-70^−/− mice.

Thymocytes and splenocytes from control (●, ▪) and ZAP-70^−/− (○, ■) mice administered tilorone 24 hours before collecting cells were cultured for 7 days in the presence of rhIL-2 (1000 U/mL). Cells were harvested and cultured with⁵¹Cr-labeled YAC-1 (●, ○) or P815 (▪, ■) cells at indicated effector:target ratios for 4 hours. Percent specific lysis was calculated as described in “Materials and methods.”