NK Cell Education and CIS Interaction Between Inhibitory NK Cell Receptors and Their Ligands
Natural killer (NK) cells are major players of the innate immunity. Their capacity to synthesize cytokines and chemokines, to lyse various cells and to allow crosstalk between innate and adaptive immunity, make them important angular effector cells in the global immune system.
NK cells have to be “educated” to correctly fulfill their functions. The expression of inhibitory receptors (IR) must be regulated in a way such that NK cells remain tolerant towards normal autologous cells while recognizing and eliminating cells that have lost, in part or in total, the expression of autologous major histocompatibility complex class I (MHC-I) molecules. This loss frequently reflects tumor transformations or viral infections. In other words, NK cells are “educated” or “selected” for sparing normal autologous cells (normal presence of “self”) and for detecting abnormal autologous cells (abnormal absence of “self,” in other words “missing-self”) which leads to the elimination of diseased cells. The mechanisms of this education/selection process have not yet been completely elucidated, although dramatic progress has been made in recent years.
KeywordsNatural Killer Cell Natural Killer Cell Population Tetramer Binding Natural Killer Cell Development Ly49 Receptor
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