Killer-cell immunoglobulin-like receptor

Killer-cell immunoglobulin-like receptors (KIRs), are a family of cell surface proteins found on important cells of the immune system called natural killer (NK) cells. They regulate the killing function of these cells by interacting with MHC class I molecules, which are expressed on all cell types. This interaction allows them to detect virally infected cells or tumor cells that have a characteristic low level of Class I MHC on their surface. Most KIRs are inhibitory, meaning that their recognition of MHC suppresses the cytotoxic activity of their NK cell. Only a limited number of KIRs have the ability to activate cells.^[1] KIR molecules are highly polymorphic, meaning their gene sequences differ greatly between individuals, so that different individuals possess different arrays/repertoires of KIR genes.^[2]

Genes

• two domains, long cytoplasmic tail: KIR2DL1, KIR2DL2, KIR2DL3, KIR2DL4, KIR2DL5A, KIR2DL5B,
• two domains, short cytoplasmic tail: KIR2DS1, KIR2DS2, KIR2DS3, KIR2DS4, KIR2DS5
• three domains, long cytoplasmic tail: KIR3DL1, KIR3DL2, KIR3DL3
• three domains, short cytoplasmic tail: KIR3DS1

See also

• Leukocyte immunoglobulin-like receptors

References

1. ↑ Vilches C, Parham P (2002). "KIR: diverse, rapidly evolving receptors of innate and adaptive immunity". Annu Rev Immunol 20: 217–51. doi:10.1146/annurev.immunol.20.092501.134942. PMID 11861603. 
2. ↑ Uhrberg M (2005). "The KIR gene family: life in the fast lane of evolution". Eur J Immunol 35 (1): 10–5. doi:10.1002/eji.200425743. PMID 15580655. 

External links

• http://www.KIRtyping.info
• The KIR Gene Cluster, NIH Bookshelf, PDF
• killer cell immunoglobulin-like receptor at the US National Library of Medicine Medical Subject Headings (MeSH)