LILRB1 Human
Description
Functional Roles in Immune Regulation
LILRB1 serves as an immune checkpoint receptor with diverse roles:
Immune Suppression
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Inhibits NK cell cytotoxicity and T cell activation by competing with CD8 for MHC class I binding .
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Promotes tolerogenic dendritic cell differentiation, dampening adaptive immune responses .
Tumor Microenvironment Modulation
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In multiple myeloma (MM), LILRB1 facilitates cholesterol uptake via LDLR/LDLRAP1 complexes, protecting cancer cells from ferroptosis .
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High LILRB1 expression on tumor-associated macrophages (TAMs) correlates with reduced phagocytosis and poor prognosis in solid tumors .
Autoimmunity
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Germline LILRB1 variants (e.g., rs1061680) impair SHP-1 phosphorylation, leading to dysregulated Treg function and autoimmune phenotypes .
Cholesterol Metabolism in Cancer
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Role in MM: LILRB1 deficiency in MM cells reduces LDL/cholesterol uptake, increasing oxidative stress and ferroptosis susceptibility .
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Pathway Activation: LILRB1-KD MM cells exhibit upregulated fatty acid β-oxidation and ROS production, linked to ferroptosis activation .
Ligand Interactions
Cancer Prognosis
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Multiple Myeloma: High LILRB1 expression correlates with aggressive progression and poor survival (median OS: 2 years vs. 5 years in low expressers) .
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Prostate Cancer: Elevated LILRB1+ NK cells in late-stage disease suggest immune exhaustion .
Therapeutic Targeting
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Antibody Blockade: Anti-LILRB1 mAbs (e.g., B1-176) restore NK cell cytotoxicity against MM, leukemia, and solid tumors in preclinical models .
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Combination Therapies: Synergy with PD-1/CTLA-4 inhibitors is under investigation to overcome myeloid-driven immunosuppression .
Genetic and Epigenetic Regulation
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Polymorphisms: Over 58 SNVs identified in LILRB1, with rs1061679 and rs1061680 linked to altered receptor stability and expression .
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Enhancer Regions: A 3-kb enhancer in intron 1, regulated by YY1, drives lymphoid-specific transcription .
Population-Specific Diversity:
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Brazilian cohorts show high haplotype diversity (13 major haplotypes), influenced by admixture and selection pressures .
Future Directions
Product Specs
Leukocyte Immunoglobulin Like Receptor B1 (LILRB1), a member of the leukocyte immunoglobulin-like receptor (LIR) family, is found on immune cells. It binds to MHC class I molecules on antigen-presenting cells, transmitting a negative signal that suppresses immune responses. This inhibitory action helps regulate inflammation, cytotoxicity, and self-reactivity. LILRB1 is present on various immune cells, including B cells, monocytes, subsets of NK cells, gamma delta T cells, memory/effector CD8+ T cells, and monocyte-derived dendritic cells.
Recombinant human LILRB1, produced in Sf9 Baculovirus cells, is a single, glycosylated polypeptide chain. It comprises 446 amino acids (24-461 a.a), resulting in a molecular weight of 48.5 kDa. The protein includes an 8 amino acid His-tag at the C-terminus and is purified using proprietary chromatographic methods.
The LILRB1 solution is provided at a concentration of 0.25 mg/ml in a buffer containing 10% glycerol and Phosphate-Buffered Saline (pH 7.4).
For short-term storage (2-4 weeks), the LILRB1 solution can be stored at 4°C. For extended storage, freezing at -20°C is recommended. The addition of a carrier protein (0.1% HSA or BSA) is advised for long-term storage. To maintain protein integrity, avoid repeated freeze-thaw cycles.
The purity of LILRB1 is determined to be greater than 95.0% using SDS-PAGE analysis.
The biological activity of LILRB1 is greater than 50%. This activity is assessed by the protein's ability, when immobilized, to support the adhesion of HSB2 human peripheral blood acute lymphoblastic leukemia cells. The cells are introduced to LILRB1-coated plates at a concentration of 5 µg/ml.
Leukocyte immunoglobulin-like receptor subfamily B member 1,
Leukocyte immunoglobulin-like receptor 1, leucocyte Ig-like receptor B1, CD85 antigen-like family member J, Immunoglobulin-like transcript 2, myeloid inhibitory receptor 7, Monocyte/macrophage immunoglobulin-like receptor 7, Ig-like transcript 2, MIR-7, LILRB1, ILT2, LIR1, MIR7, LIR-1, ILT-2, PIRB, PIR-B
Sf9, Baculovirus cells.
GHLPKPTLWA EPGSVITQGS PVTLRCQGGQ ETQEYRLYRE KKTAPWITRI PQELVKKGQF PIPSITWEHT GRYRCYYGSD TAGRSESSDP LELVVTGAYI KPTLSAQPSP VVNSGGNVTL QCDSQVAFDG FILCKEGEDE HPQCLNSQPH ARGSSRAIFS VGPVSPSRRW WYRCYAYDSN SPYEWSLPSD LLELLVLGVS KKPSLSVQPG PIVAPEETLT LQCGSDAGYN RFVLYKDGER DFLQLAGAQP QAGLSQANFT LGPVSRSYGG QYRCYGAHNL SSEWSAPSDP LDILIAGQFY DRVSLSVQPG PTVASGENVT LLCQSQGWMQ TFLLTKEGAA DDPWRLRSTY QSQKYQAEFP MGPVTSAHAG TYRCYGSQSS KPYLLTHPSD PLELVVSGPS GGPSSPTTGP TSTSGPEDQP LTPTGSDPQS GLGRHLGVLE HHHHHH
Product Science Overview
Leukocyte Immunoglobulin-Like Receptor B1 (LILRB1), also known as CD85j, LIR1, and ILT2, is a transmembrane glycoprotein that plays a crucial role in the immune system. It is a member of the leukocyte immunoglobulin-like receptor (LILR) family, which includes both activating and inhibitory receptors that regulate immune cell activity .
LILRB1 is a protein-coding gene that belongs to the subfamily B class of LIR receptors. The encoded protein contains two or four extracellular immunoglobulin domains, a transmembrane domain, and two to four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs) . These ITIMs are essential for the inhibitory function of LILRB1, as they recruit phosphatases that dephosphorylate signaling molecules, thereby downregulating immune cell activation .
LILRB1 is expressed on various immune cells, including neutrophils, monocytes, macrophages, dendritic cells, and some subsets of T and B cells . It serves as a receptor for human leukocyte antigen G (HLA-G), a non-classical major histocompatibility complex (MHC) class I molecule that plays a role in immune tolerance . By binding to HLA-G, LILRB1 can inhibit the activation of immune cells, thereby preventing excessive inflammation and tissue damage .
Elevated expression of LILRB1 has been associated with poor prognosis in certain cancers, such as glioma . In glioma, higher LILRB1 expression is linked to increased tumor immune infiltration and poorer patient outcomes. This suggests that LILRB1 may play a role in tumor immune evasion and could be a potential target for immunotherapy .
Recombinant human LILRB1 is produced using recombinant DNA technology, which involves inserting the gene encoding LILRB1 into a suitable expression system, such as bacteria or mammalian cells. This allows for the large-scale production of the protein for research and therapeutic purposes . Recombinant LILRB1 can be used to study its structure, function, and interactions with other molecules, as well as to develop potential therapeutic interventions targeting LILRB1.
