Regulation of NKG2D Ligand MICA by p53

NKG2D is a stimulatory receptor used by natural killer (NK) cells and some types of T cells of the immune system to detect infected and transformed cells. It recognizes and binds to NKG2D ligands––a family of ligands which are upregulated in diseased cells, which include MICA, MICB, and ULBP1-5 in humans and h60a-c, RAE-1a-e, and Mult-1 in mice. NKG2D ligands are expressed constitutively on primary tumors by poorly understood mechanisms. In addition, there is also active repression of NKG2D ligand expression by normal cells by mechanisms, which may be subverted in pathology by cancer cells and viruses. Therefore understanding the molecular mechanisms of upregulation during early stages of carcinogenesis and downregulation during later stages may have an important implication in cancer and immune disease therapeutics