Inhibitory MHC class I receptors on NK cells and T cells.

Natural killer (NK) and T cells express receptors for polymorphic major histocompatibility complex (MHC) class I molecules, and activation of these receptors results in inhibition of their effector cell function. Genes encoding the murine and human NK-cell receptors have been cloned, and studies of their structure, function and expression are progressing rapidly, as reviewed here by Lewis Lanier and Joseph Phillips.