Interleukin 18, Recombinant, Rat (IL-18, IFN-gamma inducing factor, IGIF)

Interleukin-18 is a member of the interleukin-1 family of cytokines with pro-inflammatory and tumor-suppressive properties. Its ability to potently enhance the production of interferon-gamma indicates in particular the crucial function of interleukin-18 as an immunomodulatory molecule. In fact, high levels of interleukin-18 are detected in human diseases associated with immunoactivation including viral or bacterial infections and chronic inflammation. Animal models suggest suppression of interleukin-18 bioactivity as a novel therapeutic concept specifically for the treatment of chronic inflammatory diseases such as rheumatoid arthritis, Crohn's disease, and psoriasis. It is the only cytokine with a unique capacity to induce T helper 1 or T helper 2 polarization, depending on the immunologic context.\n\nDescription: \nRecombinant Rat IL-18 produced in E.Coli is a single, non-glycosylated polypeptide chain containing 158 amino acids and having a molecular mass of 18260 Dalton. Recombinant Rat Interleukin-18 is purified by proprietary chromatographic techniques.\n\nAmino Acid Sequence: \nThe sequence of the first five N-terminal amino acids was determined and was found to be His-Phe-Gly-Arg-Leu.\n\nDimers and Aggregates: \nLess than 1% as determined by silver-stained SDS-PAGE gel analysis.\n\nBiological Activity: \nRat IL-18 is fully biologically active when compared to standard. The ED50 as determined by the dose-dependent stimulation of IFN-gamma by murine lymph node cells (4 x 105 cells/well) co-stimulated with sub optimal dose of ConA (0.75ug/ml) is 12 ng/ml. The medium was RPMI containing 10% FCS and 50microM 2-ME.\n\nProtein Content: \nProtein quantitation was carried out by two independent methods: \n1. UV spectroscopy at 280 nm using the absorbency value of 0.213 as the extinction coefficient for a 0.1% (1mg/ml) solution. This value is calculated by the PC GENE computer analysis program of protein sequences (IntelliGenetics). \n2. Analysis by RP-HPLC, using a standard solution of IL-18 as a Reference Standard.\n\nEndotoxin: \n(same/less than) 0.1ng/ug (IEU/ug) of rat IL-18.\n\nSolubility: \nIt is recommended to reconstitute the lyophilized IL-18 in sterile 18MOmega-cm H2O not less than 100microg/ml, which can then be further diluted to other aqueous solutions.\n\nStability: \nLyophilized Interlekin-18 although stable at room temperature for 3 weeks, should be stored desiccated below -180C. Upon reconstitution IL-18 should be stored at 40C between 2-7 days and for future use below -180C. For long term storage it is recommended to add a carrier protein (0.1% HSA or BSA). Please avoid freeze-thaw cycles.

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SPECIFICATIONS

Catalog Number

I8439-95R1

Size

5ug

Form

Supplied as a lyophilized powder in 0.4X PBS, pH 7.2.

Purity

(same/more than) 95% as determined by RP-HPLC, anion-exchange FPLC and/or reducing and non-reducing SDS-PAGE Silver Stained gel.

References

1. Lack of association of interleukin-18 gene polymorphisms with susceptibility of Japanese populations to Graves' disease or Graves' ophthalmopathy.\n\nThyroid 2006 Mar;16(3):243-8\n\n2. Interleukin 18 and human immunodeficiency virus type I infection in adolescents and adults.\n\nClin Exp Immunol 2006 Apr;144(1):117-24\n\n3. Interleukin-18: a novel prognostic cytokine in bacteria-induced sepsis.\n\nCrit Care Med 2006 Apr;34(4):1225-33\n\n4. MyD88 deficiency results in tissue-specific changes in cytokine induction and inflammation in interleukin-18-independent mice infected with Borrelia burgdorferi.\n\nInfect Immun 2006 Mar;74(3):1462-70\n\n5. Interleukin 1 and interleukin 18 as mediators of inflammation and the aging process.\n\nAm J Clin Nutr 2006 Feb;83(2):447S-455S\n\n6. Interleukin-18 mRNA expression in the rat pituitary gland.\n\nJ Neuroimmunol 2006 Apr;173(1-2):117-25