Sensitivity of the CD34⁺ EB cell–derived LAK cells to various cytokines. (A) Difference in response to IL-2. Type I LAK cells (LAK34a-1; □, ▪, ✺; and LAK34-a-3: ▵, ▴, ✺), and type II LAK cells (LAK34a-2: ○, •, ✺) were cultured at 5,000 cell/well/0.1 mL coculture medium for 48 hours in the presence of different concentration of IL-2 (□, ○, ▵), IL-12 (✺), IL-15 (▪, •, ▴), and SCF (✺). The 1 (10⁰) × dilution corresponds to 0.5 μg/mL of added cytokine except that, in the case of SCF, 1× dilution is 10 μg/mL. The cell viability was measured with alamar blue dye. Note that singly added IL-12 and SCF do not show any signal. (B) Effect of IL-12 and SCF on the IL-2–activated type II LAK cells. LAK34a-2 cells were cultured in a fixed concentration of IL-2 (3 ng/mL) (□), with various concentrations of IL-12 (0.5 μg/mL at 1× dilution) (○), and SCF (10 μg/mL at 1× dilution) (▵). The cell viability was measured with alamar blue dye.