CMV-specific CD8⁺ T cells do not express killer inhibitory receptors.

(A) Dot plots of killer inhibitory receptor–PE fluorescence (x-axis, arbitrary units, log scale) versus NLVPMVATV–HLA-A2.1 tetramer-APC fluorescence (“tetramer,” y-axis, arbitrary units, log scale) within gated CD8^bright T cells from CMV-seropositive individuals. From left to right, expressions of CD94, NKB-1, CD158a, and CD158b are shown. (B) Frequencies of inhibitory receptor–expressing cells within CD8⁺ T cells (CD8⁺, left columns, percentage of CD8⁺ T cells) or within tetramer-positive CD8⁺ T cells (tetramer⁺, right columns, percentage of tetramer-positive CD8⁺ T cells).