Killer cell immunoglobulin-like receptor, two Ig domains and long cytoplasmic tail 5A (KIR2DL5A)

Killer cell immunoglobulin-like receptor, two Ig domains and long cytoplasmic tail 5A (KIR2DL5A) is a protein expressed on the surface of natural killer (NK) cells and some T cells[1][3]. It is part of the KIR gene family, which encodes a family of broadly polymorphic receptors that regulate NK cell activity through their interaction with major histocompatibility complex (MHC) class I molecules, specifically subsets of human leukocyte antigen (HLA) class I[1][3]. KIR2DL5A belongs to the group of KIR proteins characterized by two extracellular immunoglobulin domains and a long cytoplasmic tail, which includes immune tyrosine-based inhibitory motifs (ITIMs) responsible for transmitting inhibitory signals and suppressing NK cell-mediated cytotoxicity[1][3]. The gene is located in the leukocyte receptor complex on chromosome 19q13.4 and displays significant polymorphism[1][2][3]. Variations in KIR gene content and alleles have been associated with immune-related diseases such as cancer, infectious diseases, autoimmune disorders, graft-versus-host disease, and other immune phenotypes[1][3]. Ligands for KIR2DL5A are still being clarified and not as well characterized as for other KIRs[3]. No directly approved drugs target KIR2DL5A, though modulation of KIR activity is an area of research for immunotherapy and transplant medicine.

Other names

KI2LAKiller cell immunoglobulin like receptor two Ig domains and long cytoplasmic tail 5AKIR2DL5NKAT11

Inhibits NK cell cytotoxicity via immune tyrosine-based inhibitory motifs (ITIMs) upon ligand engagement