LILRB1/CD85j (D4L8L) Rabbit Monoclonal Antibody #78144

The leukocyte Ig-like receptor subfamily B (LILRB) are type-I transmembrane glycoproteins containing ligand-binding extracellular IgG-like domains and immunoreceptor tyrosine-based inhibition motifs (ITIMS) within the cytoplasmic domain, which recruit SHP protein tyrosine phosphatases, leading to transduction of signals that inhibit immune cell activation. Encoded within a region of chromosome 19 known as the leukocyte receptor complex, the LILRB subfamily of inhibitory receptors consists of LILRB1 to LILRB5, also referred to as CD85J, CD85D, CD85A, CD85K, and CD85C, respectively (1). There is mounting evidence that LILRBs function, in part, as a novel class of immune checkpoint receptors and support tumor growth through the transmission of inhibitory signals upon engagement of ligands expressed on tumor cells (2).

LILRB1 (CD85j/ILT2/LIR1) is expressed across multiple hematopoietic cell lineages, such as B-cells, NK cells, monocytes, and T-cells (3,4). Like other members of the LILRB subfamily, LILRB1 contains multiple extracellular IgG-like domains and intracellular ITIM motifs (5). Research studies have demonstrated that LILRB1 interacts with multiple HLA class I ligands, such as HLA-G (6). Cross-linking of LILRB1 upon ligand engagement has been shown to activate immunosuppressive signaling cascades, which in B-cells, suppresses their activation and ability to produce antibodies (7). In NK and T cell lineages, research studies have shown that LILRB1 transduces signaling to inhibit cytolytic activity (3).