Phenotypic characterization of NK-cell subsets in peripheral blood of rhesus macaques. (A) Representative flow cytometric plots defining NK cells in PBMCs. Macaque NK cells were identified using a broad side- versus forward-scatter gate and phenotypically defined as CD3⁻CD8α⁺NKG2A⁺. Subsets were further delineated by expression of CD56 and/or CD16. (B) Representative histogram overlays depict expression of NKp46 and NKp30 on each of the 3 primary NK subsets. Gray closed histograms are from isotype-matched controls. CD56⁺ indicates CD56⁺CD16⁻; CD16⁺, CD56⁻CD16⁺; and DN, CD56⁻CD16⁻. Examples are representative of 15 to 27 naive animals.