Natural killer cell receptor protein 1C (NKR-P1C)

Natural killer cell receptor protein 1C (NKR-P1C) is a C-type lectin-like type II transmembrane receptor primarily expressed on mouse natural killer (NK) cells, NKT cells, and certain progenitor thymocytes. It is encoded by the Klrb1c gene and is recognized experimentally as the NK1.1 antigen in select mouse strains (e.g., C57BL/6). Upon engagement (such as with specific monoclonal antibodies), NKR-P1C mediates NK cell activation, leading to interferon-gamma production and cytotoxicity toward target cells. Its natural ligands and detailed biological roles are complex and under continued investigation, but it plays critical roles in NK cell recognition of transformed, infected, or stressed cells. Some members of the NKR-P1 family are inhibitory, but NKR-P1C is considered stimulatory. The NKR-P1/Clr receptor-ligand system is evolutionarily conserved among mammals, although with key species differences. In humans, the closest functional analog is NKR-P1A (CD161, KLRB1), not NKR-P1C.

Other names

NK1.1CD161cKlrb1c (gene name in mouse)NKR-P1CNK-RP1CNKRP1C

Monoclonal antibodies (such as PK136 in mice) can activate NKR-P1C, leading to NK cell activation, interferon-gamma production, and cytotoxic degranulation. Antibody ligation triggers association with the Fc receptor gamma (FcRγ) signaling adaptor, leading to downstream immune signaling.