Association of NK cell activation receptors with distinct signaling adaptors. (A) 293T cells were transiently transfected with expression vectors for NKG2D-S, Ly49H, Ly49D, and NKRP-1C (NK1.1) together with DAP10 or DAP12 adaptor constructs. Transfected cells were analyzed by flow cytometry for surface expression of the respective NK cell receptors. Data are representative of 2 to 3 independent experiments. Numbers on plots are percentages of total cells carrying the indicated cell receptor. (B) Lysates of NK cells cultured in IL-2 for 7 days were immunoprecipitated with Abs to NKG2D, Ly49D, Ly49H, CD16, NK1.1, and NKp46, separated by reducing SDS-PAGE. Associated proteins were detected by Western blot (WB) with Abs to DAP10, DAP12, and FcRγ. (C) Three days IL-2–cultured NK cells from B6 (○) or mice lacking DAP12 function (DAP12ki; □) were used as effectors against CHO cells. To ensure Ly49D dependence of CHO lysis, the Ly49D receptor was blocked with mAb 4E5 (controls •, and DAP12ki NK cells, ■). Data are representative of 2 independent experiments. Error bars are SD.