Recombinant Human IL-18Rβ-Fc Chimera (carrier-free)

Pricing & Availability
Regulatory Status
Other Names
IL-18 receptor accessory protein, IL-18RAP, Accessory protein-like, AcPL, CDw218b, CD218b, IL-1R accessory protein-like, IL-1RAcPL, IL-1R7, IL-18R-beta, IL-18Rbeta, IL-18Rb
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Product Citations
Recombinant human IL-18Rβ-Fc chimera inhibits the induction of IFN-γ by human IL-18 in human KG-1 cells. The ED50 for this effect is 1 – 5 µg/mL.
  • Human_IL-1818Rbeta_CF_RECOM_1_121020.png
    Recombinant human IL-18Rβ-Fc chimera inhibits the induction of IFN-γ by human IL-18 in human KG-1 cells. The ED50 for this effect is 1 – 5 µg/mL.
  • Human_IL-1818Rbeta_CF_RECOM_2_121020.png
    Stability Testing for Recombinant Human IL-18Rβ-Fc Chimera. Recombinant human IL-18Rβ-Fc chimera was aliquoted in PBS, pH 7.2 at 0.2 mg/mL. One aliquot was frozen and thawed four times (4x Freeze/Thaw) and compared to the control that was kept at 4⁰C (Control). The samples were tested for their ability to inhibit the induction of IFN-γ by human IL-18 in human KG-1 cells. The ED50 for this effect is 1 – 5 µg/mL.
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790404 25 µg 118€
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790406 100 µg 268€
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790408 500 µg 797€
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IL-18 is essential for both innate and adaptive immunity. IL-18 receptor is composed of an α and a β subunit that form a high affinity heterodimer for IL-18. IL-18Rβ chain, also known as IL-18RAcP and CD218b, is a type I transmembrane protein. It is expressed on NK cells, neutrophils, endothelial cells, and subsets of T and B cells. The expression of IL-18Rα and IL-18Rβ on lymphocytes are upregulated upon IL-12 stimulation. Upon IL-18 engagement, the intracellular TIR domain of IL- IL-18Rα and IL-18Rβ recruits adaptor proteins, MyD88, and in turn recruits IRAK and TRAF6, activating the NF-κB and MAPK pathways, which upregulate the production of various inflammatory cytokines. The interaction of IL-18 and IL-18 receptor has been reported to be implicated in promotion of Th1 cytokine production and atherogenesis. Antibodies against IL-18Rβ inhibit IL-18-induced responses. Several splice isoforms of IL-18Rβ were identified thus, a known polymorphism on the IL-18Rβ gene leads to reduced expression of IL-18Rβ and reduced pattern-recognition receptor (PRR)-induced cytokine secretion in monocyte-derived macrophages.

Product Details
Technical data sheet

Product Details

Human IL-18Rβ, amino acid Phe20-Arg356 (Accession #O95256.1), with a linker (SSLGS) and a C-terminal human IgG (Pro100-Lys330), was expressed in CHO cells.
Molecular Mass
The 573 amino acid recombinant protein has a predicted molecular mass of approximately 64.82 kD. The DTT-reduced and non-reduced protein migrates at approximately 90 kD and 180 kD by SDS-PAGE, respectively. The predicted N-terminal amino acid is Phe.
> 95%, as determined by Coomassie stained SDS-PAGE
0.22 µm filtered protein solution in PBS
Endotoxin Level
Less than 0.01 ng per µg cytokine as determined by the LAL method.
10 and 25 µg sizes are bottled at 200 µg/mL. 100 µg size and larger sizes are lot-specific and bottled at the concentration indicated on the vial. To obtain lot-specific concentration and expiration, please enter the lot number in our Certificate of Analysis online tool.
Storage & Handling
Unopened vial can be stored between 2°C and 8°C for up to 2 weeks at -20°C for up to six months, or at -70°C or colder until the expiration date. For maximum results, quick spin vial prior to opening. The protein can be aliquoted and stored at -20°C or colder. Stock solutions can also be prepared at 50 - 100 µg/mL in appropriate sterile buffer, carrier protein such as 0.2 - 1% BSA or HSA can be added when preparing the stock solution. Aliquots can be stored between 2°C and 8°C for up to one week and stored at -20°C or colder for up to 3 months. Avoid repeated freeze/thaw cycles.
The ED50 is 1 - 5 μg/mL, as determined by a dose-dependent inhibition of human IL-18-induced IFN-γ secretion by KG-1 cells in the presence of 10 ng/mL human IL-18 (Cat. No. 592102) and 30 μg/mL human IL-18Rα.


Application Notes

BioLegend carrier-free recombinant proteins provided in liquid format are shipped on blue-ice. Our comparison testing data indicates that when handled and stored as recommended, the liquid format has equal or better stability and shelf-life compared to commercially available lyophilized proteins after reconstitution. Our liquid proteins are validated in-house to maintain activity after shipping on blue ice and are backed by our 100% satisfaction guarantee. If you have any concerns, contact us at

Antigen Details

Disulfide-linked homodimer

Expressed on NK cells and neutrophils, IL-12 activated T and B cells, endothelial cells, and smooth muscle cells; highly expressed on Hodgkin's disease cell lines; plasma membrane

IL-18Rα forms a receptor complex with IL-18Rβ and mediates IL-18 function.
Human IL-18Rβ inhibits the induction of IFN-γ by human IL-18 in human KG-1 cells.
Cell Type
B cells, Endothelial cells, Leukocytes, Lymphocytes, Neutrophils, NK cells, T cells, Th1
Biology Area
Adaptive Immunity, Immunology, Innate Immunity
Molecular Family
Fc Receptors, Soluble Receptors
Antigen References

1. Born TL., et al. 1998. J Biol Chem. 273: 29445. 
2. Airoldi I., et al. 2000. J Immunol. 165: 6880.
3. Debets R., et al. 2000. J Immunol. 165: 4950. 
4. Adachi O., et al. 1998. Immunity. 9: 143. 
5. Tsutsumi N.. et al. 2014. Nat Comm. 5: 5340.
6. Hedl M., et al. 2014. J Immunol. 192: 5924.
7. Fiszer D., et al. 2007. Cytokine 39: 178. 
8. Kato Z., et al. 2003. Nat Struc Biol. 10: 966.

Gene ID
8807 View all products for this Gene ID
View information about IL-18Rbeta on

Related FAQs

Why choose BioLegend recombinant proteins?

     • Each lot of product is quality-tested for bioactivity as indicated on the data sheet.
     • Greater than 95% Purity or higher, tested on every lot of product.
     • 100% Satisfaction Guarantee for quality performance, stability, and consistency.
     • Ready-to-use liquid format saves time and reduces challenges associated with reconstitution.
     • Bulk and customization available. Contact us.
     • Learn more about our Recombinant Proteins.

How does the activity of your recombinant proteins compare to competitors?

We quality control each and every lot of recombinant protein. Not only do we check its bioactivity, but we also compare it against other commercially available recombinant proteins. We make sure each recombinant protein’s activity is at least as good as or better than the competition’s. In order to provide you with the best possible product, we ensure that our testing process is rigorous and thorough. If you’re curious and eager to make the switch to BioLegend recombinants, contact your sales representative today!

What is the specific activity or ED50 of my recombinant protein?

The specific activity range of the protein is indicated on the product datasheets. Because the exact activity values on a per unit basis can largely fluctuate depending on a number of factors, including the nature of the assay, cell density, age of cells/passage number, culture media used, and end user technique, the specific activity is best defined as a range and we guarantee the specific activity of all our lots will be within the range indicated on the datasheet. Please note this only applies to recombinants labeled for use in bioassays. ELISA standard recombinant proteins are not recommended for bioassay usage as they are not tested for these applications.

Have your recombinants been tested for stability?

Our testing shows that the recombinant proteins are able to withstand room temperature for a week without losing activity. In addition the recombinant proteins were also found to withstand four cycles of freeze and thaw without losing activity.

Does specific activity of a recombinant protein vary between lots?

Specific activity will vary for each lot and for the type of experiment that is done to validate it, but all passed lots will have activity within the established ED50 range for the product and we guarantee that our products will have lot-to-lot consistency. Please conduct an experiment-specific validation to find the optimal ED50 for your system.

How do you convert activity as an ED50 in ng/ml to a specific activity in Units/mg?

Use formula Specific activity (Units/mg) = 10^6/ ED50 (ng/mL)

Go To Top Version: 1    Revision Date: 12.10.2020

For Research Use Only. Not for diagnostic or therapeutic use.


This product is supplied subject to the terms and conditions, including the limited license, located at ("Terms") and may be used only as provided in the Terms. Without limiting the foregoing, BioLegend products may not be used for any Commercial Purpose as defined in the Terms, resold in any form, used in manufacturing, or reverse engineered, sequenced, or otherwise studied or used to learn its design or composition without express written approval of BioLegend. Regardless of the information given in this document, user is solely responsible for determining any license requirements necessary for user’s intended use and assumes all risk and liability arising from use of the product. BioLegend is not responsible for patent infringement or any other risks or liabilities whatsoever resulting from the use of its products.


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