Immunomodulation of NK Cell Activity

Natural killer (NK) cells can kill virus-infected cells and tumor cells without prior sensitization and secrete numerous cytokines and chemokines that modulate the activity of different cells of the immune system. The recognition of target cells is mediated by germ line-encoded receptors, and the activity of NK cells can be further regulated by soluble factors such as cytokines and Toll-like receptor ligands. Thus, NK cells display an exciting potential as a powerful immunotherapeutic tool against malignant diseases, and different strategies are being tested aiming to overcome tumor-induced NK cell suppression and restore NK-cell mediated antitumor activity. This section describes different flow cytometry-based protocols to study NK cell effector functions, which can be used to evaluate the immunomodulatory ability of different therapeutic compounds.