Interleukin 4, aa25-153, Recombinant, Human (IL-4)

Interleukin-4 (IL-4), also known as B cell-stimulatory factor-1, is a monomeric, ~13kD-18kD Th2 cytokine that shows pleiotropic effects during immune responses (1-3). It is a glycosylated polypeptide that contains three intrachain disulfide bridges and adopts a bundled four a-helix structure (4). Human IL-4 is synthesized with a 24aa signal sequence. Alternate splicing generates an isoform with a 16aa internal deletion. Mature human IL-4 shares 55%, 39%, 43% aa sequence identity with bovine, mouse, and rat IL-4, respectively. Human, mouse, and rat IL-4 are species-specific in their activities (5-7). IL-4 exerts its effects through two receptor complexes (8, 9). The type I receptor, which is expressed on hematopoietic cells, is a heterodimer of the ligand binding IL-4 Ra and the common y chain (a shared subunit of the receptors for IL-2, -7, -9, -15, and -21). The type II receptor on nonhematopoietic cells consists of IL-4 Ra and IL-13 Ra1. The type II receptor also transduces IL-13 mediated signals. IL-4 is primarily expressed by Th2-biased CD4+ T cells, mast cells, basophils, and eosinophils (1, 2). It promotes cell proliferation, survival, and immunoglobulin class switch to IgG4 and IgE in human B cells, acquisition of the Th2 phenotype by native CD4+ T cells, priming and chemotaxis of mast cells, eosinophils, and basophils, and the proliferation and activation of epithelial cells (10 - 13). IL-4 plays a dominant role in the development of allergic inflammation and asthma (12, 14).\n\nSource: \nRecombinant corresponding to aa25-153 from human IL-4, expressed in CHO cells.\n\nMolecular Weight: \n~15kD\n\nEndotoxin Level:\n(same/less than)1EU/1ug (LAL)\n\nBiological Activity:\nMeasured in a cell proliferation assay using TF-1 human erythroleukemic cells. Kitamura, T. et al. (1989) J. Cell Physiol. 140:323. The ED50 for this effect is typically 0.05-0.2ng/ml.\n\nStorage and Stability:\nLyophilized powder may be stored at -20 degrees C. Stable for 12 months at -20 degrees C. Reconstitute with PBS. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Reconstituted product is stable for 6 months at -20 degrees C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.

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SPECIFICATIONS

Catalog Number

I8426-48D

Size

10ug

Form

Supplied as a lyophilized powder in PBS. Reconstitute with PBS to 100ug/ml.

Purity

~95% (SDS-PAGE)

References

1. Benczik, M. and S.L. Gaffen (2004) Immunol. Invest. 33:109. 2. Chomarat, P. and J. Banchereau (1998) Int. Rev. Immunol. 17:1. 3. Yokota, T. et al. (1986) Proc. Natl. Acad. Sci. 83:5894. 4. Redfield, C. et al. (1991) Biochemistry 30:11029. 5. Ramirez, F. et al. (1988) J. Immunol. Meth. 221:141. 6. Leitenberg, D. and T.L. Feldbush (1988) Cell. Immunol. 111:451. 7. Mosman, T.R. et al. (1987) J. Immunol. 138:1813. 8. Mueller, T.D. et al. (2002) Biochim. Biophys. Acta 1592:237. 9. Nelms, K. et al. (1999) Annu. Rev. Immunol. 17:701. 10. Paludan, S.R. (1998) Scand. J. Immunol. 48:459. 11. Corthay, A. (2006) Scand. J. Immunol. 64:93. 12. Ryan, J.J. et al. (2007) Crit. Rev. Immunol. 27:15. 13. Grone, A. (2002) Vet. Immunol. Immunopathol. 88:1. 14. Rosenberg, H.F. et al. (2007) J. Allergy Clin. Immunol. 119:1303.