Human Killer Cell Immunoglobulin Like Receptor 2DL3 (KIR2DL3) Protein

Background

KIR2DL3 is an inhibitory receptor that is part of the killer cell immunoglobulin-like receptor (KIR) family, which is primarily expressed on natural killer (NK) cells and some T-cell subsets. This receptor plays a pivotal role in immune surveillance and modulation by binding to specific HLA class I molecules, particularly HLA-C alleles, on potential target cells. KIR2DL3 recognizes HLA-C1 (characterized by an asparagine at position 80), which is different from HLA-C2 (lysine at position 80) recognized by related receptors like KIR2DL1. By binding to HLA-C1, KIR2DL3 sends inhibitory signals that regulate NK cell cytotoxicity, promoting immune tolerance and minimizing the risk of autoimmunity. The KIR genes, including KIR2DL3, are located on chromosome 19q13.4 in a highly polymorphic region known as the leukocyte receptor complex (LRC). Genetic variability within this complex, particularly in the KIR2DL3 and its HLA-C ligands, contributes to diversity in immune response among individuals. Variants in KIR2DL3 and other KIR genes are associated with differential susceptibility to diseases, including autoimmune disorders, viral infections, and cancers.