Figure 1. Phenotype of DNAM-1⁺ and DNAM-1⁻ NK cells.

(A) Expression of DNAM-1 on NK cells in the spleen, blood, BM, and liver, gating on TCRβ⁻NK1.1⁺ lymphocytes. Thin and bold lines represent staining with control Ig and anti-DNAM-1 mAb. (B) Developmental stages of DNAM-1⁺ and DNAM-1⁻ NK cells as determined by co-staining with CD27 and CD11b, gating on TCRβ⁻NK1.1⁺ lymphocytes. (C) Ly49H expression on DNAM-1⁺ (thick lines) and DNAM-1⁻ (thin lines) NK cells, gated on TCRβ⁻NK1.1⁺ lymphocytes. Percentages of Ly49H⁺ NK cells in DNAM-1⁺ (bold numbers) and DNAM-1⁻ NK (thin numbers) cells are shown. (D) Expression of Ly49C and/or Ly49I on DNAM-1⁺ (thick lines) and DNAM-1⁻ (thin lines) NK cells. Data are representative of 2–4 experiments. (E) IFN-γ production and degranulation of Ly49H⁺DNAM-1⁺ and Ly49H⁺DNAM-1⁻ NK cells after co-culture with RMA cells expressing m157, CD155, or m157 and CD155. Data are representative of 2 independent experiments (n = 3–6 per experiment). (F) Twenty-five million WT splenocytes were transferred into DAP12-deficient mice and infected with 1 × 10⁵ pfu MCMV. IFN-γ production by Ly49H⁺ NK cells was analyzed by intracellular staining on day 1.5 pi. Percentages of IFN-γ⁺Ly49H⁺ NK cells and mean fluorescent intensity (MFI) of IFN-γ of Ly49H⁺ NK cells within the DNAM-1⁺ and DNAM-1⁻ Ly49H⁺ NK cell subsets are shown. Data are representative of 3 experiments (n = 3–4 mice per experiment). Error bars show s.e.m. *p <0.05.