Isolation and characterization of human natural killer cell subsets

Natural killer (NK) cells are innate immune lymphocytes that play a critical role in the host defense against pathogens through their production of cytokines and cytotoxic activity. Human NK cells can be divided into two subsets, each with distinct phenotypic and functional properties, based on cell-surface density expression of CD56 (CD56bright and CD56dim). This unit describes the purification of human NK cell subsets from blood, protocols for the further characterization of NK cell function, and further background information on these cell types.