<i>In vitro</i> stimulation of NK cells with m157-Tg splenocytes alone induces DAP12-dependent degranulation.

(A-C) Splenocytes from CD45.2 WT or indicated strain were mixed with CD45.1/2 congenic m157-Tg or WT splenocytes at a 1:1 ratio in the presence of the indicated cytokines. IFNβ was used at 100–200 U/ml, IL-12 was used at 10–20 ng/ml. NK cell degranulation was measured after a 6–9 hr incubation. (A) Representative FACS plots are shown on the left and percentage of CD107a+ cells within the Ly49H+ NK cell population of biological duplicates is shown on the right. (B) Jinx or B6.BxD8 splenocytes were mixed with m157-Tg or control splenocytes. For experiments with B6.BxD8 percentage of CD107a+ NK cells is calculated over the whole NK cell population. (C) DAP10-/- or DAP12 KI splenocytes were mixed with adapter-expressing m157-Tg or control splenocytes. (D) Purified NK cells were cultured with m157-Tg or WT control murine embryonic fibroblasts (MEF) and analyzed as in (A). Data are representative of at least two independent experiments.