FIGURE 5.

Effector properties of VEX⁺ NK cells. a, Freshly isolated splenocytes from H2-SVEX (SB88) mice were FACS sorted into VEX⁺ (VEX^POS) or VEX⁻ (VEX^NEG) NK1.1⁺TCRβ⁻ subsets, after which 3 × 10⁴ cells were stimulated with 2 ng/ml IL-2 and 1 ng/ml IL-12 for 6 h. Brefeldin A was added for the last 3 h of culture. Samples were then harvested and stained with Abs to detect intracellular IFN-γ by flow cytometry. FSC, Forward scatter; unstim, unstimulated. b, FACS-sorted VEX⁺ or VEX⁻ NK1.1⁺TCRβ⁻ spleen cells from H2-SVEX (SB88) mice were expanded in the presence of 6,000 IU/ml IL-2 for 6 days and then 3 × 10⁵ cells of each subset were stimulated with IL-2 plus IL-12 as above for 48 h. Supernatants were then collected for ELISA analysis. Each point in b represents an individual animal. Data from both SB88 and SB110 mice are included in each plot. c, Freshly sorted VEX⁺ or VEX⁻ NK1.1⁺TCRβ⁻ splenic NK cells (6, 000) from H2-SVEX (SB88) mice were cultured with IL-2 and IL-12 as above with or without YAC-1 targets at a 1:1 E:T ratio. After 5 h of coculture in the presence of Abs to CD107a and CD107b, total CD107 expression was examined on NK1.1⁺ NK cells. d, H2-SVEX (SB110 mice) were cultured in the presence of 6,000 IU/ml IL-2 for 6 days after which cytolytic activity against chromium-labeled YAC-1 targets was examined at the indicated E:T ratios. e, Infiltration of B16 lung metastases by IL-2-expanded VEX⁺ vs VEX⁻ spleen NK cells. Donor NK cells are visualized by immunostaining with PE-conjugated anti-Thy1.2 Ab.