IL18BP: Interleukin 18 Binding Protein
A key regulator of IL-18 activity in immune and inflammatory responses
Gene Information Card
| Symbol | IL18BP |
|---|---|
| Full Name | interleukin 18 binding protein |
| Gene Type | protein coding |
| Chromosomal Location | 11q13.4 |
| NCBI Gene ID | 10068 ncbi.nlm.nih.gov/gene/10068 |
| Ensembl ID | ENSG00000137496 |
| UniProt ID | O95998 |
| OMIM ID | 604113 |
| HGNC ID | 5989 |
| Aliases | IL18BP, IL-18BP, IL18BPa, IL18BPb, IL18BPc, IL18BPd |
Description
IL18BP encodes the interleukin 18 binding protein, a secreted protein that binds to interleukin 18 (IL-18) with high affinity and neutralizes its activity. It functions as a natural inhibitor of IL-18-mediated immune responses, including interferon-gamma production and Th1 cell activation. Alternative splicing generates multiple isoforms (a, b, c, d) with varying affinities and tissue distributions.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Inflammatory bowel disease (Crohn's disease) | Reduced IL18BP levels lead to unopposed IL-18 activity, promoting intestinal inflammation | ClinVar, PMID: 20628021 |
| Rheumatoid arthritis | Imbalance between IL-18 and IL18BP contributes to synovial inflammation | NCBI Gene, PMID: 15208739 |
| Systemic lupus erythematosus | Altered IL18BP expression correlates with disease activity | OMIM, PMID: 16920933 |
| Sepsis | IL18BP modulates IL-18-driven cytokine storm in severe infection | UniProt, PMID: 11564765 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Lung | 12.5 | Medium |
| Spleen | 8.3 | Medium |
| Small intestine | 6.1 | Low |
| Colon | 5.4 | Low |
| Liver | 4.2 | Low |
| Kidney | 3.8 | Low |
| Heart | 2.1 | Not detected |
| Brain | 1.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| THP-1 (monocyte) | 15.2 | High expression after LPS stimulation |
| HeLa (cervical) | 2.3 | Low baseline expression |
| A549 (lung) | 4.1 | Moderate expression |
| HepG2 (liver) | 1.8 | Low expression |
| Jurkat (T-cell) | 0.9 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | missense | <0.01% | Potential loss of start codon; likely loss of function |
| c.200C>T (p.Pro67Leu) | missense | <0.01% | Unknown significance; rare variant |
| c.340G>A (p.Gly114Arg) | missense | <0.01% | Unknown significance; rare variant |
| c.500_501insA | frameshift | <0.01% | Predicted loss of function; truncation |
Mutation functional classification
Loss of Function (LOF)
Mutations that disrupt the start codon or cause frameshifts/truncations likely reduce or abolish IL-18 binding and neutralization, leading to increased IL-18 activity.
Gain of Function (GOF)
No gain-of-function mutations have been reported in IL18BP.
Dominant Negative (DN)
No dominant-negative mutations have been described for IL18BP.
View complete mutation data：
Gene Ontology (GO)
| • cytokine activity (GO:0005125) | • protein binding (GO:0005515) |
| • extracellular region (GO:0005576) | • extracellular space (GO:0005615) |
| • cytokine binding (GO:0019955) | • interleukin-18 binding (GO:0032611) |
| • identical protein binding (GO:0042802) | • negative regulation of interleukin-18 production (GO:0045079) |
| • negative regulation of inflammatory response (GO:0050728) | • defense response to Gram-positive bacterium (GO:0050830) |
Pathways
• Interleukin-18 signaling pathway (Reactome: R-HSA-448424)
• Cytokine-cytokine receptor interaction (KEGG: hsa04060)
• NOD-like receptor signaling pathway (KEGG: hsa04621)
• Toll-like receptor signaling pathway (KEGG: hsa04620)
• Inflammatory bowel disease (KEGG: hsa05321)
Protein Summary
The IL-18 binding protein (IL-18BP) is a secreted glycoprotein of approximately 40 kDa that binds to mature IL-18 with high affinity (Kd ~0.4 nM), preventing IL-18 from interacting with its receptor. It is constitutively expressed in many tissues and upregulated during inflammation. Four major isoforms (a, b, c, d) arise from alternative splicing; isoform a is the most abundant and has the highest affinity. IL-18BP acts as a natural antagonist of IL-18-driven Th1 and NK cell responses, and its dysregulation is implicated in autoimmune and inflammatory diseases.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| IL18BP Knockout HEK293 Cell Line | EDJ-KQ2452 | Human | 10068 | Details Get a Quote |
| IL18BP Knockout HCT 116 Cell Line | EDJ-KQ22982 | Human | 10068 | Details Get a Quote |
| IL18BP Knockout HeLa Cell Line | EDJ-KQ22983 | Human | 10068 | Details Get a Quote |
| IL18BP Knockout A-549 Cell Line | EDJ-KQ21648 | Human | 10068 | Details Get a Quote |
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