Critical contribution of perforin to α-GalCer–induced cytotoxicity by NK cells.

Hepatic MNCs were obtained from B6 WT mice 3 hours (A) or 24 hours (B) after intraperitoneal injection of α-GalCer (▪, 2 μg/200 μL) or vehicle (■, 200 μL), as indicated. Liver MNCs were also harvested after 24 hours from B6 gld mice (D), B6 pfp^−/− mice, (E) or B6 WT mice that were depleted of NK cells with anti-asGM1 antibody (F). Cytotoxicity against B16F10 melanoma targets was tested in a 20-hour ⁵¹Cr release assay at the indicated effector–target ratios. Some MNCs from B6 WT mice were also incubated in the presence of 10 μg/mL neutralizing anti-mIFN–γ mAb (C) as described.30 Data are represented as the mean ± SE of triplicate samples and are representative of 2 experiments.