Human Killer cell lectin-like receptor subfamily G member 1

Killer cell lectin-like receptor subfamily G member 1 is a protein that in humans is encoded by the KLRG1 gene.

NK cells are a type of immune cell that can kill virus-infected cells and certain tumor cells without the need for prior activation. They also play a role in regulating both humoral and cell-mediated immunity.

The KLR family of proteins, to which the protein encoded by this gene belongs, is expressed predominantly in NK cells and is composed of transmembrane proteins. Research in mice has indicated that the expression of this gene may be regulated by MHC class I molecules. KLRG1 is a co-inhibitory receptor that is expressed primarily on late-differentiated effector and effector memory CD8+ T and NK cells. Its ligands, E-cadherin and N-cadherin, are markers of epithelial and mesenchymal cells, respectively.

Targeting co-inhibitory receptors, such as CTLA-4, PD-1, and PD-L1, has gained significant interest for use in cancer immunotherapy. However, KLRG1 has received relatively fewer studies compared to other co-inhibitory receptors due to its characterization as a "senescent" marker rather than an "exhaustion" marker.

KLRG1 knockout mice have been found to have enhanced immunity in a tuberculosis challenge model, although they initially showed no abnormal features. Further research is needed to fully understand the role of KLRG1 in immune function and potential therapeutic applications.