Fig. 4.

Ly49G+ and Ly49G− NK cells display similar cytotoxicity and cytokine production after stimulation. (A) IL-2-expanded C57BL/6 NK cells were sorted into Ly49G+ and Ly49G− subsets and tested for cytotoxicity against YAC-1, RMA-S, YB2/0, and YB-D^d cell targets using a standard ⁵¹Cr release assay. Data are representative of two independent experiments. (B) Freshly prepared Tg3-D^k (TgMN3) and non-Tg splenocytes were incubated with immobilized anti-NK1.1 in the presence of Brefeldin A. PMA and ionomycin (P/I) stimulation was included as a positive control. After 4 h, cells were stained for DX5, CD3, 4D11, and intracellular IFN-γ. Shown are representative dot plots; the numbers represent the percentages of IFN-γ+ cells among the Ly49G2+ or Ly49G2− populations of NK cells. (C) Experimental means measured in triplicate for %IFN-γ+ Tg3-D^k NK cells sorted by Ly49G expression (Left) or %IFN-γ+ Ly49G+ NK cells sorted by Tg3-D^k or non-Tg (Right). Data are representative of four different experiments with 2–3 mice per genotype. Statistical significance was determined by Wilcoxon rank-sum test. (D) Relative IFN-γ productivity is plotted as a ratio of the percentage of IFN-γ+ cells among the Ly49G2+ NK cells to the percentage of IFN-γ+ cells among the Ly49G2− NK cells as described (5).