IL-15 was discovered in the supernatant from a simian kidney epithelial cell line CV-1/EBNA, as a soluble factor capable of supporting proliferation of the IL-2-dependent cell line, CTLL-2 (1). Interleukin-15 (IL-15) is a regulatory cytokine, and it is produced by dendritic cells, epithelial cells, human stromal cell line (IMTLH), fibroblasts, and monocytes (2). IL-15 plays an important role in immune response and shares many functions with IL-2, for example, stimulating the proliferation of activated T cells (1, 2), NK cells (3) and B cells, and inducing immunoglobulin synthesis by B cells stimulated by anti-IgM or CD40 ligand (4). In addition, IL-15 promotes the development of dendritic cells (5), activates human neutrophils (6, 7) and induces the production of proinflammatory cytokines from macrophages (8). IL-15 acts as a bridge between innate and adaptive immunity because of its diverse roles in the immune system. IL-15 binds to heterotrimeric receptors composed of IL-15Rα, IL-15Rβ, and IL-15Rγc. IL-15 shares with IL-2 the receptor chains β and γc. IL-15 is normally not secreted in soluble form but is held on the cell surface bound to a unique receptor, IL-15Rα, especially on dendritic cells. Cell-bound IL-15 then is presented in trans to T cells and NK cells and is recognized by the γc receptor on these cells; such recognition maintains cell survival and intermittent proliferation (9).Product Details
- Human IL-15, amino acids Asn49-Ser162 (Accession# NM_000585), was expressed in E. coli.
- Molecular Mass
- The 114 amino acid recombinant protein has a predicted molecular mass of 12,773 Da. The DTT-reduced protein migrates at approximately 9kDa and the non-reduced protein migrates at approximately 7kDa by SDS-PAGE. The N-terminal amino acid is Asn.
- Purity is >98%, as determined by Coomassie stained SDS-PAGE.
- 0.22 µm filtered protein solution is in 10mM NaH2PO4, 150mM NaCl, pH 7.2.
- Endotoxin Level
- Endotoxin level is <0.1 EU/µg (<0.01ng/µg) protein as determined by the LAL method.
- 10 and 25 µg sizes are bottled at 200 µg/mL. 100 µg size and larger sizes are lot-specific and bottled at the concentration indicated on the vial (please contact technical support for concentration, or use our Lookup tool if you have a lot number.) Please note, new lots of the 100 µg size will be lot-specific and may differ from previous lots that had a fixed concentration.
- Storage & Handling
- Unopened vial can be stored between 2°C and 8°C for up to 2 weeks, at -20°C for up to six months, or at -70°C or colder until the expiration date. For maximum results, quick spin vial prior to opening. The protein can be aliquoted and stored at -20°C or colder. Stock solutions can also be prepared at 50 - 100 µg/mL in appropriate sterile buffer, carrier protein such as 0.2 - 1% BSA or HSA can be added when preparing the stock solution. Aliquots can be stored between 2°C and 8°C for up to one week and stored at -20°C or colder for up to 3 months. Avoid repeated freeze/thaw cycles.
- ED50 = 2 - 10 ng/ml, corresponding to a specific activity of 0.1 - 0. 5 x 106 units/mg, as determined by the dose dependent stimulation of MO7e cell proliferation.
- Recommended Usage
Use when high specific biological activity is required.
- Application Notes
This IL-15 protein is biologically active and can be used for in vitro assays.
BioLegend carrier-free recombinant proteins provided in liquid format are shipped on blue-ice. Our comparison testing data indicates that when handled and stored as recommended, the liquid format has equal or better stability and shelf-life compared to commercially available lyophilized proteins after reconstitution. Our liquid proteins are validated in-house to maintain activity after shipping on blue ice and are backed by our 100% satisfaction guarantee. If you have any concerns, contact us at email@example.com.
(PubMed link indicates BioLegend citation)
- Correia DV, et al. 2011. Blood 118:992. (BA) PubMed
- Product Citations
- 13 kD single non-glycosylated polypeptide
IL-15 is expressed by DC, epithelial cells, human stromal cell line (IMTLH), fibroblasts, and monocytes.
- IL-15 stimulates the proliferation of activated T cells (1, 2), NK cells (3) and B cells, and inducing immunoglobulin synthesis by B cells stimulated by anti-IgM or CD40 ligand (4). In addition, IL-15 promotes the development of dendritic cells (5), activates human neutrophils (6, 7) and induces the production of proinflammatory cytokines from macrophages (8).
- stimulatory activities on the proliferation, survival and activation of T lymphocytes and NK cells, and the pathogenesis of rheumatoid arthritis via activating T cells and induces IL-17 production
- Cell Sources
- adherent peripheral blood mononuclear cells, fibroblasts and epithelial cells
- Cell Targets
- T lymphocytes, NK cells
- IL-15Rα, IL-15Rβ and IL-15γc
- Cell Type
- Hematopoietic stem and progenitors
- Biology Area
- Immunology, Innate Immunity, Stem Cells, Cell Biology
- Molecular Family
- Antigen References
1. Grabstein K, et al. Science 264:965-968 1994.
2. Ma A, et al. Annu Rev Immunol 24:657-679 2006.
3. Meresse B, et al. Immunity 21:357-366 2004.
4. Armitage RJ et al, J Immunol 154:483-490 1995.
5. Pulendran B, et al. Eur. J. Immunol. 34:66-73 2004.
6. Bouchard A, et al. J. Leukoc. Biol. 76:162-168 2004.
7. Ratthe C, et al. 2004. J. Leukoc. Biol. 75:893.
8.Feng T, et al. 2008. Cell Immunol 5:189.
9. Rubinstein MP et al, P. Natl. Acad. Sci. USA 103:9166-9171 2006.
- Gene ID
- 3600 View all products for this Gene ID
- View information about IL-15 on UniProt.org
- Does specific activity of a recombinant protein vary between lots?
Specific activity will vary for each lot and for the type of experiment that is done to validate it, but all passed lots will have activity within the established ED50 range for the product and we guarantee that our products will have lot-to-lot consistency. Please conduct an experiment-specific validation to find the optimal ED50 for your system.
- Have your recombinants been tested for stability?
Our testing shows that the recombinant proteins are able to withstand room temperature for a week without losing activity. In addition the recombinant proteins were also found to withstand four cycles of freeze and thaw without losing activity.
- How do you convert activity as an ED50 in ng/ml to a specific activity in Units/mg?
- Use formula Specific activity (Units/mg) = 10e6/ ED50 (ng/mL)
- How does the activity of your recombinant proteins compare to competitors?
We quality control each and every lot of recombinant protein. Not only do we check its bioactivity, but we also compare it against other commercially available recombinant proteins. We make sure each recombinant protein’s activity is at least as good as or better than the competition’s. In order to provide you with the best possible product, we ensure that our testing process is rigorous and thorough. If you’re curious and eager to make the switch to BioLegend recombinants, contact your sales representative today!
- What is the specific activity or ED50 of my recombinant protein?
The specific activity range of the protein is indicated on the product datasheets. Because the exact activity values on a per unit basis can largely fluctuate depending on a number of factors, including the nature of the assay, cell density, age of cells/passage number, culture media used, and end user technique, the specific activity is best defined as a range and we guarantee the specific activity of all our lots will be within the range indicated on the datasheet. Please note this only applies to recombinants labeled for use in bioassays. ELISA standard recombinant proteins are not recommended for bioassay usage as they are not tested for these applications.