Recombinant human IL-18 protein - Bioactive cytokine

Human IL-18 protein - E. coli -expressed, tag-free, with HSA

Recombinant human IL-18 is a high-quality and biologically active cytokine, validated using proprietary IL-18 reporter cells. This member of the IL-1/TLR cytokine superfamily is produced in E. coli and thoroughly purified to remove endotoxins.

Recombinant human IL-18 can be used together with HEK-Blue™ IL-18 cells for the screening of inhibitory molecules, such as Camoteskimab, a monoclonal antibody targeting IL-18 (see figures).

IL-18 signaling and biological functions

Key features

• Each lot is validated using HEK-Blue™ IL-18 cells
• Endotoxin < 10 EU/mg
• 0.2 µm sterile-filtered

Applications

• Standard for IL-18 detection and quantification assays
• Screening and release assays for antibodies blocking IL-18 signaling
• Screening and release assays for engineered IL-18

Interleukin 18 (IL-18) is a pro-inflammatory cytokine and a powerful inducer of type 1 responses mediated by activated NK, Th1, and CD8+ cytotoxic T cells. Abnormal IL-18 serum concentration is associated with immune-mediated inflammation diseases, including cryopyrin-associated periodic syndrome (CAPS), familial mediterranean fever (FMF), and multiple sclerosis.

 More details

InvivoGen’s products are for internal research use only, and not for human or veterinary use.

Figures

SDS PAGE of the recombinant human (h)IL-18 protein. 1.5 μg of hIL-18 was loaded on a 12% Mini-PROTEAN® TGX Stain-Free™ Precast Gel (Bio-Rad) stained with Coomassie. Detection was performed as per the manufacturer’s instructions. A band was detected at ~18 kDa.

Dose-response in HEK-Blue™ IL-18 cells to recombinant IL-18 cytokine. Cells were stimulated with increasing concentrations of recombinant human IL-18. After overnight incubation, the NF-κBinduced SEAP activity was determined using QUANTI-Blue™, a SEAP detection reagent. Data are shown as optical density (OD) at 650 nm (mean ± SEM).

Dose-dependent inhibition of HEK-Blue™ IL-18 cells response using Camoteskimab biosimilar. Increasing concentrations of Anti-hIL-18-hIgG1-FES (0.1 ng/ml - 10 µg/ml) were incubated with recombinant human (h)IL-18 (30 pg/ml) for 1 h before the addition of HEK-Blue™ IL-18 cells. After overnight incubation, SEAP activity in the cell culture supernatant was assessed using QUANTI-Blue™ Solution. Data are shown in percentage of activity (%) (mean ± SEM).

Specifications

Source: E. coli

Species: Human

Alternative names: Iboctadekin, Interferon gamma-inducing factor

Carrier: HSA (human serum albumin)

Tag: Tag-free

Accession number: Q14116

Protein size: 157 a.a. (T37-D193)

Molecular weight: ~ 18 kDa (SDS-PAGE)

Solubility: 100 μg/ml in water

Formulation: Phosphate buffer saline (pH 7.4), 5% saccharose, 2% HSA

Sterility: 0.2 µm filtration

Form: Lyophilized

Reconstitution buffer: Endotoxin-free water (provided)

Purity: ≥95% (SDS-PAGE)

Endotoxin: The absence of bacterial contamination (e.g. lipoproteins and endotoxins) has been confirmed using HEK-Blue™ TLR2 and HEK‑Blue™ TLR4 cells.

Tested applications: Cellular assays

Quality control: Each lot is functionally tested and validated

Contents

Recombinant human IL-18 is provided as a lyophilized powder and is available in two quantities:

• rcyec-hil18: 10 μg
• rcyec-hil18-5: 50 μg (5 x 10 μg)
• 1.5 ml endotoxin-free water for rcyec-hil18 and rcyec-hil18-5

Recombinant human IL-18 is shipped at room temperature.

Upon receipt, the product should be stored at -20 °C.

 Avoid repeated freeze-thaw cycles.

Details

Interleukin-18 (IL-18), formerly called interferon-γ (IFN-γ) inducing factor, is a pro-inflammatory cytokine that causes a wide variety of biological effects associated with infection, inflammation, and autoimmune processes [1, 2]. More specifically, IL-18 induces IFN-γ production and contributes to T-helper 1 (Th1) cell polarization.

IL-18 is produced by macrophages and other cells, as a pro-protein which is proteolytically processed to its active form by caspase 1, an enzyme that is activated within the inflammasome multiprotein complex. It binds to a heterodimeric receptor consisting of IL-18R and IL-18 receptor accessory protein (IL-18RAP). Upon binding, IL-18 activates NF-κB and AP-1 via signaling pathways that involve TRAF-6 [3, 4].

1. Yasuda K. et al., 2019. Interleukin-18 in health and disease. Int J Mol Sci. 20(3).
2. Dinarello CA. et al., 1998. Overview of interleukin-18: more than an interferon-gamma inducing factor. J Leukoc Biol. 63(6):658-64.
3. Gracie JA. et al., 2003. Interleukin-18. J Leukoc Biol.3(2):213-24.
4. Kojima H. et al., 1998. Interleukin-18 activates the IRAK-TRAF6 pathway in mouse EL-4 cells. BBRC 244(1):183-6.