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).
Source:Recombinant corresponding to aa25-153 from human IL-4, expressed in CHO cells.
Molecular Weight:~15kD
Endotoxin Level:≤1EU/1ug (LAL)
Biological Activity:Measured 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.
Storage and Stability:Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with PBS. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Reconstituted product is stable for 6 months at -20°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.
仕様
Size：10ug
Source Antigen：Recombinant, CHO
Grade：Highly Purified
Purity：~95% (SDS-PAGE)
Form：Supplied as a lyophilized powder in PBS. Reconstitute with PBS to 100ug/ml.
