CD161 is a 30 kDa type II transmembrane C-type lectin that is expressed as a homodimer. The NKR-P1 receptor in rats is mainly expressed on NK cells, T cell subsets, dendritic cells and activated monocytes. There are three different types of NKR-P in rats, namely NKR-P1a, NKR-P1b and NKR-P1c. NKR-P1a does not contain an ITIM structure and is an activating receptor, while NKR-P1b contains an ITIM and has an inhibitory function. LLT-1 (ligand lectin like transcript 1) is the ligand, while KLR (killer cell lectin like) acts as the receptor.
