LILRB4
LILRB4 (leukocyte immunoglobulin like receptor B4, also known as ILT3, LIR-5, LIR5, HM18 and CD85k) is an inhibitory cell-surface receptor of the LIR family. It helps down-regulate immune responses and supports the development of immune tolerance. Browse Assay Genie's current range of LILRB4 research reagents below, or read on for the biology behind the target.
LILRB4 is an inhibitory receptor that dampens immune activation. It inhibits receptor-mediated phosphorylation of cellular proteins and the mobilisation of intracellular calcium ions. In monocytes, it opposes FCGR1A/CD64-mediated activation by driving phosphatase-mediated down-regulation of the phosphorylation of several proteins, including LCK, SYK, LAT and ERK, which reduces TNF production. This effect occurs at least in part through binding to FN1.
The receptor also acts on adaptive immunity. It inhibits T cell proliferation, induces anergy, suppresses the differentiation of IFNG-producing CD8+ cytotoxic T cells and enhances the generation of CD8+ T suppressor cells. It induces up-regulation of CD86 on dendritic cells and interferes with TNFRSF5 signalling and NF-kappa-B up-regulation. Reported ligands include FN1, apolipoprotein APOE and ALCAM/CD166. NCBI describes binding to MHC class I molecules on antigen-presenting cells, transduction of a negative signal, and a role in antigen capture and presentation. It is thought to help focus the immune response and limit autoreactivity.
The LILRB4 gene belongs to the leukocyte immunoglobulin-like receptor cluster at 19q13.4. Subfamily B receptors have two or four extracellular immunoglobulin domains, a transmembrane domain and two to four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs). Multiple transcript variants encoding different isoforms have been described. The protein is classed among the CD molecules and the inhibitory leukocyte immunoglobulin like receptors, and was previously named leukocyte immunoglobulin-like receptor, subfamily B (with TM and ITIM domains), member 4.
LILRB4 is involved in down-regulating immune responses and developing immune tolerance, including T cell anergy and the generation of CD8+ T suppressor cells.
LILRB4 inhibits FCGR1A/CD64-mediated monocyte activation by reducing phosphorylation of LCK, SYK, LAT and ERK, lowering TNF production.
LILRB4 induces up-regulation of CD86 on dendritic cells and interferes with TNFRSF5 signalling and NF-kappa-B up-regulation.
LILRB4 is thought to control inflammatory responses and cytotoxicity, helping to focus the immune response and limit autoreactivity.
LILRB4 is an inhibitory receptor that down-regulates immune responses and promotes immune tolerance. It limits phosphorylation signalling and calcium mobilisation, suppresses monocyte activation and TNF production, and inhibits T cell proliferation. Its reported ligands include FN1, APOE and ALCAM/CD166.
LILRB4 is also known as ILT3, LIR-5, LIR5, HM18 and CD85k. Its earlier name was leukocyte immunoglobulin-like receptor, subfamily B (with TM and ITIM domains), member 4. Multiple transcript variants encoding different isoforms have been reported for the gene.
LILRB4 belongs to subfamily B of the leukocyte immunoglobulin-like receptor family, whose genes cluster at 19q13.4. Subfamily B members share extracellular immunoglobulin domains, a transmembrane domain and cytoplasmic ITIMs. Check the datasheet of any product for its validated reactivity.
Other inhibitory leukocyte immunoglobulin-like receptors from the same subfamily B.
Gene and protein annotations from HGNC, NCBI Gene and UniProt Q8NHJ6; product specifications from Assay Genie datasheets.