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Recombinant Human IL-18 Protein

Cat # Size Price Quantity
63020110 µg$125
630202100 µg$550

  Bulk/Custom

Product Details

ApplicationBioassay
FormatLyophilized from sterile PBS, pH 7.4.
Expression HostE.coli
Target NameIL-18, IL18, IL1F4, Interferon-gamma-inducing factor, IGIF, IL-1g
SpeciesHuman
accession numberNP_001553.1
SourcesA DNA sequence encoding the human IL18 (NP_001553.1) (Tyr37-Asp193) was expressed.
Molecular WeightThe recombinant human IL18 consists 157 amino acids and predicts a molecular mass of 18.2 kDa.
Affinity TagNone
Purity> 95 % as determined by SDS-PAGE. > 95 % as determined by SEC-HPLC.
Regulatory StatusRUO
Endotoxin level<0.01EU per μg protein
Protein ConcentrationLyophilized
Storage and HandlingProteins are stable for up to twelve months from date of receipt at -20℃ to -80℃. Store it under sterile conditions at -20℃ to -80℃. It is recommended that the protein be aliquoted for optimal storage. Avoid repeated freeze-thaw cycles.
Research AreasCytokines, Inflammation, Th1 cells, NK cells, NKT cells, Wound Healing, Autoimmunity

Background Information

Human interleukin-18 (IL-18) is a proinflammatory cytokine belonging to the IL-1 family, with a key role in innate and adaptive immunity. It is produced by macrophages, dendritic cells, epithelial cells, and other tissues as an inactive precursor that requires cleavage by caspase-1 within the inflammasome to become biologically active. IL-18 is best known for its ability to induce interferon-gamma (IFN-γ) production from natural killer (NK) cells and T cells, especially in synergy with IL-12, thereby promoting T helper 1 (Th1) immune responses.

Structurally, IL-18 is a single-chain polypeptide that adopts a β-trefoil fold typical of IL-1 family cytokines. Its primary receptor is a heterodimer composed of IL-18Rα (binding chain) and IL-18Rβ (accessory chain), which together initiate downstream signaling through the MyD88-dependent pathway and activation of NF-κB and MAP kinases. A natural high-affinity antagonist, IL-18 binding protein (IL-18BP), tightly regulates IL-18 activity by preventing receptor engagement.

Dysregulated IL-18 expression is implicated in inflammatory and autoimmune diseases such as rheumatoid arthritis, psoriasis, and inflammatory bowel disease, as well as in metabolic and cardiovascular disorders. Elevated IL-18 levels are also associated with severe infections and cytokine storm syndromes. Therapeutically, targeting IL-18 signaling—particularly through recombinant IL-18BP or neutralizing antibodies—has emerged as a strategy to control excessive inflammation. Conversely, IL-18 is being explored as an immune activator in cancer immunotherapy to enhance anti-tumor responses.

Data Sheets

Recombinant Human IL-18 Protein TDS

Frequently Asked Questions

What are InnoCyto's Cytokines and Growth Factors?
These are recombinantly expressed signaling proteins, including interleukins, interferons, chemokines, and growth factors, that mediate cell communication, proliferation, differentiation, and immune activation. They are produced for use as research reagents to stimulate, modulate, or study cellular responses in vitro and in vivo.
What expression systems are these proteins produced in, and does it matter for my application?
Cytokines and growth factors may be produced in mammalian, insect, or E. coli expression systems depending on the protein, and the system affects properties like glycosylation, folding, and bioactivity. Non-glycosylated proteins from E. coli are often suitable for cell culture stimulation assays, while glycosylation-dependent proteins may require mammalian- or insect-expressed versions for full biological activity — check the product page for the expression system and recommended applications.
How is bioactivity measured and confirmed for each lot?
Bioactivity is typically confirmed using a functional cell-based assay (e.g., proliferation, differentiation, or reporter assay) relevant to the specific cytokine or growth factor, and is reported as an EC50/ED50 value or specific activity (units/mg) on the Certificate of Analysis. Always reference the lot-specific CoA rather than assuming activity is identical across lots or products.
Are these proteins carrier-free, and does that matter for my experiment?
Carrier-free formulations (without BSA or other stabilizing proteins) are available for applications where carrier protein could interfere with downstream analysis, such as certain in vivo studies or proteomic work, while carrier-containing formulations offer improved stability for routine cell culture use. Choose the format that matches your assay's sensitivity to background protein content.
Can these cytokines and growth factors be used for in vivo studies?
Mouse proteins may be used in vivo, but suitability depends on your endotoxin requirements for in vivo use. Endotoxin minimum threshholds vary by product and are indicated on the individual product page. Always confirm the endotoxin specification and formulation on the Certificate of Analysis before using a product in an in vivo setting.

Have a product or application question? Consult our FAQs or contact us.