Recombinant Feline IL-18/IL-1F4 Protein

• Reactivity: Fe
• Applications: Bioactivity

Recombinant Feline IL-18/IL-1F4 Protein Summary

• Details of Functionality: Measured by its ability to induce IFN-gamma secretion by KG‑1 human acute myelogenous leukemia cells in the presence of TNF-alpha . The ED₅₀ for this effect is 0.200-5.00 μg/mL in the presence of 20 ng/mL recombinant human TNF-alpha .
• Source: E. coli-derived feline IL-18/IL-1F4 protein
  Tyr36-Asn192, with an N-terminal Met
• Accession #: Q95M33
• N-terminal Sequence: Met
• Protein/Peptide Type: Recombinant Proteins
• Purity: >90%, by SDS-PAGE under reducing conditions and visualized by silver stain.
• Endotoxin Note: <0.01 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 18.3 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 19 kDa, reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in MOPS, Na₂SO₄, EDTA and DTT with BSA as a carrier protein.
• Purity: >90%, by SDS-PAGE under reducing conditions and visualized by silver stain.
• Reconstitution Instructions: Reconstitute at 100 μg/mL in PBS containing at least 0.1% human or bovine serum albumin.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Feline IL-18/IL-1F4 Protein

• Iboctadekin
• IFN-gamma-inducing factor
• IGIF
• IGIFIL-1 gamma
• IL18
• IL-18
• IL-18MGC12320
• IL-1F4
• IL1F4iboctadekin
• IL-1g
• Interferon gamma-inducing factor
• interleukin 18 (interferon-gamma-inducing factor)
• Interleukin-1 gamma
• interleukin-18

Background

Interleukin-18 (IL-18) is a proinflammatory cytokine in the IL-1 family that exerts distinct immune effects depending on the local cytokine environment. It is expressed as a 24 kDa precursor by endothelial and epithelial cells, keratinocytes, gamma δ T cells, and phagocytes. The precursor is activated intracellularly by Caspase-1 mediated proteolysis to release the 17 kDa mature cytokine. The precursor can also be released by necrotic cells for extracellular cleavage by multiple proteases.
IL-18 activation is induced by infection or tissue damage and contributes to disease pathology in chronic inflammation (1-3). IL-18 binds to the widely expressed IL-18 R alpha which recruits IL-18 R beta to form the signaling receptor complex (4, 5). Its bioactivity is negatively regulated by interactions with IL-18 binding proteins and virally encoded IL-18BP homologs (6). In the presence of IL-12 or IL-15, IL-18 enhances anti-viral Th1 immune responses by inducing IFN-gamma production and the cytolytic activity of CD8⁺ T cells and NK cells (7, 8). In the absence of IL-12 or IL-15, however, IL-18 promotes production of the Th2 cytokines IL-4 and IL-13 by CD4⁺ T cells and basophils (9, 10). In the presence of IL-1 beta or IL-23, IL-18 induces the antigen-independent production of IL-17 by gamma δ T cells and CD4⁺ T cells (11). IL-18 also promotes myeloid dendritic cell maturation and triggers neutrophil respiratory burst (12, 13). In cancer, IL-18 exhibits diverse activities including enhancing anti-tumor immunity, inhibiting or promoting angiogenesis, and promoting tumor cell metastasis (14). Mature feline IL-18 shares 87% - 89% aa sequence identity with canine and porcine IL-18 and 62% - 77% with human, mouse, rat, and rhesus IL-18 (15).

1. Dinarello, C.A. et al. (2013) Front. Immunol. 4:289.
2. Smith, D.E. (2011) J. Leukoc. Biol. 89:383.
3. Gu, Y. et al. (1997) Science 275:206.
4. Torigoe, K. et al. (1997) J. Biol. Chem. 272:25737.
5. Cheung, H. et al. (2005) J. Immunol. 174:5351.
6. Novick, D. et al. (1999) Immunity 10:127.
7. Fehniger, T.A. et al. (1999) J. Immunol. 162:4511.
8. Yoshimoto, T. et al. (1998) J. Immunol. 161:3400.
9. Yoshimoto, T. et al. (2000) Nat. Immunol. 1:132.
10. Kroeger, K.M. et al. (2009) J. Leukoc. Biol. 86:769.
11. Lalor, S.J. et al. (2011) J. Immunol. 186:5738.
12. Li, J. et al. (2004) Cell. Immunol. 227:103.
13. Elbim, C. et al. (2005) Clin. Diagn. Lab. Immunol. 12:436.
14. Fabbi, M. et al. (2015) J. Leukoc. Biol. 97:665.
15. Ishizaka, T. et al. (2001) Vet. Immunol. Immunopathol. 79:209.

Bioinformatics

• Uniprot:
  • Q95M33()