Recombinant Human Interleukin-4 （IL-4）
Purified No Carrier Protein
（BCGF, BCDF, B Cell Stimulating Factor, BSF-1, MGC79402）
Prod. No.: I-186
Source E. coli
Pkg. Size: 1 mg, 10 µg, 50 µg
Storage: -20°C to -70°C Detailed storage instructions below.

Description
Background:
Interleukin-4 （IL-4）, also known as B Cell Stimulating Factor, is a pleiotropic cytokine that regulates diverse T and B cell responses including cell proliferation, survival and gene expression （1）. Produced by mast cells, T cells and bone marrow stromal cells, IL-4 regulates the differentiation of naive CD4+ T cells into helper Th2 cells, which favor a humoral immune response while suppressing a cell mediated immune response controlled by Th1 cells （2）. STAT6, a signal transducer and activator of transcription, has been shown to play a central role in mediating the immune regulatory signal of IL-4. Another dominant function of IL-4 is inducing immunoglobulin class switching to the IgG1 and IgE isotypes in B cells, as well as, up-regulating MHC class II production （3）. IL-4 is the ligand for IL-4 receptor. The IL-4 receptor also binds to IL-13, which may contribute to overlapping functions with IL-13. IL-4 plays a dominant role in the development of allergic inflammation and asthma （4）.

Source
E. coli
Molecular Weight
The predicted molecular weight of Recombinant Human IL-4 is Mr 14 kDa.
State of Matter
Lyophilized
Formulation
This recombinant protein was 0.2 µm filtered and lyophilized from modified Dulbecco’s phosphate buffered saline （1X PBS） pH 7.2 – 7.3 with no calcium, magnesium, or preservatives present.
Purity
>97% by SDS-PAGE and analyzed by silver stain.
Storage and Stability
This lyophilized protein is stable for six to twelve months when stored desiccated at -20°C to -70°C. After aseptic reconstitution, this protein may be stored at 2°C to 8°C for one month or at -20°C to -70°C in a manual defrost freezer. Avoid Repeated Freeze Thaw Cycles. See Product Insert for exact lot specific storage instructions.
Endotoxin
<1.0 EU/µg as determined by the LAL method
Biological Activity
The biological activity of Human IL-4 was determined by a cell proliferation assay using a human factor-dependent cell line, TF-1 （Kitamura, T. et al., 1989, J. Cell Physiol. 140:323）. The expected ED50 for this effect is typically 0.05 - 0.2 ng/ml.
Each investigator should determine their own optimal working dilution for specific applications.
Amino Acid Sequence
mhkcdit lqeiiktlns lteqktlcte ltvtdifaas kntteketfc raatvlrqfy shhekdtrcl gatafhrh kqlirflkrl drnlwglagl nscpvkeanq stlenflerl ktimrekysk css

Country of Origin
USA
References
1. Pike, J. W. et al. （2001） PNAS 98:2443
2. Finkelman, F. D. et al. （2003） J. Immunol. 170:3835
3. Paludan, S. R. et al. （1998） Scand. J. Immunol. 48:459
4. Ryan, J. J. et al. （2007） Crit. Rev. Immunol. 27:15

Related Products
Anti-Mouse IL-4 （Antigen Aff. Pur.） （Leinco Prod. No.: I-164）
Anti-Human IL-4 （Antigen Aff. Pur.） （Leinco Prod. No.: I-148）
Anti-Human IL-4-Biotin （Antigen Aff. Pur.） （Leinco Prod. No.: I-251）
Anti-Rat IL-4 （Antigen Aff. Pur.） （Leinco Prod. No.: I-225）
Recombinant Mouse IL-4 （Leinco Prod. No.: I-207）
Anti-Mouse IL-4-Biotin （Antigen Aff. Pur.） （Leinco Prod. No.: I-252）
Anti-Human IL-4 （Leinco Prod. No.: I-173）
Anti-Human IL-4 （Leinco Prod. No.: I-631）
Anti-Mouse IL-4 （Leinco Prod. No.: I-662）
Anti-Porcine IL-4 （Leinco Prod. No.: I-689）
Anti-Canine IL-4 （Leinco Prod. No.: I-703）
Human IL-4 ELISA Development Kit （Leinco Prod. No.: I-287）
Mouse IL-4 ELISA Development Kit （Leinco Prod. No.: I-288）
Recombinant Rat IL-4 （Leinco Prod. No.: I-221）
Anti-Rat IL-4-Biotin （Antigen Aff. Pur.） （Leinco Prod. No.: I-253）
Anti-Rat IL-4 （Leinco Prod. No.: I-673）
：      曹