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. Author manuscript; available in PMC: 2016 Oct 15.
Published in final edited form as: J Immunol. 2015 Sep 11;195(8):4010–4019. doi: 10.4049/jimmunol.1500447

FIGURE 5.

FIGURE 5

Blocking NKG2D abrogates NK killing of CSCs from cell lines and primary tumors. FPA2 (A and B) or PANC-1 (C and D) cells were cultured with activated NK cells (1:1 E:T ratio) for 16 h in the presence of the indicated Fc-chimeric proteins that blocked the indicated activation receptors. Human IgG1 purified Ab was added as an isotype-matched control. Tumors were then analyzed by flow cytometry for total numbers of remaining live tumor cells (SSChiCD45−7-AAD−) (A and C) and percentages of tumor cells expressing CD24/CD44/ALDHbright (B and D). (E) PANC-1 cells were pretreated with 80 μM ZVAD or vehicle control for 1 h, or NK cells were pretreated with 50 nM CMA for 1 h. NK cells and PANC-1 tumor cells were then mixed at a 5:1 ratio and ZVAD, CMA, or vehicle controls were adjusted to maintain the above-stated concentrations. Twenty-four hours later, wells were harvested and analyzed for ALDH expression by flow cytometry. Reductions in stem-like populations in comparison with untreated cells were determined via one-way ANOVA with a Tukey posttest. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.