Alexa Fluor® 700 Mouse Anti-Rat CD161 Antibody (S-R628)

CD161, also known as Natural Killer Cell Receptor P1B (NKR-P1B) or CLEC2D, is a type II transmembrane glycoprotein belonging to the C-type lectin-like receptor superfamily that plays a pivotal role in modulating immune responses, particularly within the context of innate and adaptive immunity. Primarily expressed on natural killer (NK) cells, NKT cells, and specific subsets of T cells—including Th17 cells and mucosal-associated invariant T (MAIT) cells—CD161 functions by binding to its endogenous ligand, LLT1 (lectin-like transcript 1), which is often upregulated on activated antigen-presenting cells and certain tumor cells. This interaction generally delivers an inhibitory signal that dampens cytotoxicity and cytokine production, thereby serving as a critical checkpoint to prevent excessive immune activation and autoimmunity; however, depending on the cellular context and co-stimulatory signals, it can also influence cell migration and tissue retention, making CD161 a significant biomarker for identifying pro-inflammatory T cell subsets involved in autoimmune diseases such as multiple sclerosis and rheumatoid arthritis, as well as a potential therapeutic target in cancer immunotherapy where blocking this axis could enhance anti-tumor immune effector functions.