NK1.1/CD161 (E6Y9G) Rabbit mAb recognizes endogenous levels of total CD161c protein from C57BL/6, SJL, and NZW mice, but not from BALB/c and 129S6 mice. Mice from other strains have not been tested. This antibody is predicted to cross-react with CD161b and may cross-react with CD161a protein in some mouse strains.

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues near the carboxy terminus of mouse NK1.1/CD161 protein.

CD161/KLRB1 (Killer cell lectin-like receptor subfamily B member 1, also known as CLEC5B and NKR-P1A) is a type II transmembrane protein that is expressed on the majority of Natural Killer (NK) cells, NK T cells, and some T lymphocytes (1). CD161/KLRB1 is also expressed on Th17 cells, promotes their generation, and modulates their function (2). Engagement with its ligand lectin-like transcript 1 (LLT1) inhibits NK cell function, while LLT1 and CD161/KLRB1 interaction in the presence of a TCR signal enhances IFN-gamma production by T cells (3,4). There are several different CD161 isoforms in rodents and some function as activating receptors as well (5,6).

There is a family of Klrb1 genes in rodents (7). PK136 antibody recognizes a specific epitope on mouse KLRB1b/c, also referred to as NK1.1, and is commonly used for detection of mouse NK cells in certain mouse strains (CE, B6, NZB, C58, Ma/My, ST, SJL, FVB). However, the epitope is absent in other mouse strains (BALB/c, AKR, CBA, C3H, DBA, 129) (8).