• Species Reactivity

  Rat

• Specificity

  Detects rat IL‑18/IL-1F4 in direct ELISAs and Western blots. In Western blots, approximately 35% cross-reactivity with recombinant mouse IL‑18 is observed and approximately 10% cross-reactivity with recombinant human IL‑18 is observed.

• Source

  Polyclonal Goat IgG

• Purification

  Antigen Affinity-purified

• Immunogen

  E. coli-derived recombinant rat IL‑18/IL-1F4    
  His37-Ser194    
  Accession # P97636

• Formulation

  Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied as a 0.2 µm filtered solution in PBS.

• Endotoxin Level

  <0.10 EU per 1 μg of the antibody by the LAL method.  

• Label

  Unconjugated

Applications

• Recommended    
  Concentration

  Sample

• Western Blot

  0.1 µg/mL

  Recombinant Rat IL‑18/IL‑1F4 (Catalog # )

• 
  

• Neutralization

  Measured by its ability to neutralize IL‑18/IL‑1F4-induced IFN‑ gamma secretion in activated mouse T cells [Ahn, H.J.     et al. (1997) J. Immunol.     159:2125]. The Neutralization Dose (ND    ₅₀) is typically 1-3 µg/mL in the presence of 15 ng/mL Recombinant Rat IL‑18/IL‑1F4 and 0.1 ng/mL Recombinant Mouse IL‑12.

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Data Examples

Preparation and Storage

• Reconstitution

  Reconstitute at 0.2 mg/mL in sterile PBS.

• Shipping

  The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. *Small pack size (SP) is shipped with polar packs. Upon receipt, store it immediately at -20 to -70 °C

• Stability & 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.

• 6 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: IL-18/IL-1F4

Interleukin-18 (IL-18), also known as IL-1F4 and IFN-gamma inducing factor (IGIF), is a member of the IL-1 family of cytokines and is a key molecule in the innate immune response (1). Rat IL-18 is synthesized as a 24 kDa proprotein that contains a 36 amino acid (aa) propeptide and a 158 aa mature region (2). Under inflammatory conditions, the propeptide is cleaved by Caspase-1 in the cytoplasm to liberate the mature nonglycosylated 18 kDa monomeric IL-18 (3, 4). Mature rat IL-18 shares 91% aa sequence identity with mouse IL-18 and 60-64% aa sequence identity with human, canine, feline, porcine, and rhesus macaque IL-18. IL-18 is secreted by a variety of cell types including macrophages, dendritic cells, and epithelial cells (1, 5). Circulating mature IL-18 is sequestered by soluble IL-18 binding proteins (IL-18 BP) that inhibit IL-18 bioactivity (6). IL-18 interacts with the widely expressed IL-18 R alpha which then recruits the signaling subunit IL-18 R beta (7, 8). The IL-1 family member IL-1F7 also binds to IL-18 R alpha but does not recruit IL-18 R beta or induce signaling (9). IL-1F7 binds IL-18 BP and enhances its neutralizing effect on IL-18 activity (9). IL-18 synergizes with other cytokines to activate NK, Th1, and Th17 cells and to increase the production of IFN-gamma (1, 5, 10-12). IL-18 can also promote Th2 cytokine release which reduces the effectiveness of antiviral responses (13, 14). Increased levels of active IL-18 contribute to the severity of autoimmunity and hypertension, while deficiency of IL-18 results in symptoms of metabolic syndrome (1, 5, 15, 16). In cancer, IL-18 stimulates Th1 and NK cells to target tumor cells, but it can also promote angiogenesis, metastasis, and tumor cell immune evasion (11).

• References:

1. Arend, W.P. et al. (2008) Immunol. Rev. 223:20.

2. Culhane, A.C. et al. (1998) Mol. Psychiatry 3:362.

3. Ghayur, T. et al. (1997) Nature 386:619.

4. Gu, Y. et al. (1997) Science 275:206.

5. Boraschi, D. and C.A. Dinarello (2006) Eur. Cytokine Netw. 17:224.

6. Novick, D. et al. (1999) Immunity 10:127.

7. Torigoe, K. et al. (1997) J. Biol. Chem. 272:25737.

8. Born, T.L. et al. (1998) J. Biol. Chem. 273:29445.

9. Bufler, P. et al. (2002) Proc. Natl. Acad. Sci. USA 99:13723.

10. Takeda, K. et al. (1998) Immunity 8:383.

11. Park, S. et al. (2007) Cell. Mol. Immunol. 4:329.

12. Yoshimoto, T. et al. (1998) J. Immunol. 161:3400.

13. Hoshino, T. et al. (2001) J. Immunol. 166:7014.

14. Iannello, A. et al. (2009) AIDS Rev. 11:115.

15. Rabkin, S.W. (2009) Nat. Clin. Pract. Cardiovasc. Med. 6:192.

16. Netea, M.G. et al. (2006) Nat. Med. 12:650.

• Long Name:

  Interleukin 18

• Entrez Gene IDs:

  3606 (Human); 16173 (Mouse); 29197 (Rat); 397057 (Porcine); 574151 (Primate)

• Alternate Names:

  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