Figure 5.

Ly49E⁺ ILC1s are effective in cytotoxicity. (A and B) Representative histograms (A) and percentages (B) of cells expressing the indicated intracellular functional molecules (GzmA, GzmB, and GzmC) in liver group 1 ILC subsets of WT B6 mice (5–8 wk old) after stimulation for 18 h with 10 ng/ml IL-12, 10 ng/ml IL-15, and 50 ng/ml IL-18. Fluorescence minus one (FMO) control was gated on total group 1 ILCs (A). (C and D) Percentages of cells expressing the indicated molecules among the liver group 1 ILC subsets for 4 h with PMA plus ionomycin (PMA + Ion; C) or with Yac-1 cells (D). Data are representative of two or three independent experiments with n = 3–6 mice per experiment (A–D). (E and F) Flow-based killing assays were performed by using liver group 1 ILC subsets of WT B6 mice (3–6 wk old) that were preactivated with IL-12, IL-15, and IL-18 for 18 h as effector cells and Yac-1 tumor cells as the target cells, with an effector–target (E:T) ratio of 10:1. Representative plots (E) and percentages (F) of 7-AAD–positive target cells after incubation with effector cells. Data are pooled from two independent experiments with n = 14–30 samples per group. Bar graphs show the mean ± SEM; one-way ANOVA, followed by Dunnett’s multiple comparison test, was used to compare the experimental groups in B–D and F; **, P < 0.01; ****, P < 0.0001.