- Other Names
- Human monocyte differentiation antigen CD14, Myeloid cell-specific leucine-rich glycoprotein
- Ave. Rating
- Submit a Review
- Product Citations
CD14 is a pattern recognition receptor important in innate immunity. CD14 exists in two forms, as a glycosylphosphatidylinositol-anchored protein on the surface of mononuclear cells and as a soluble protein in the blood. CD14 is shed from the surface of CD14-expressing cells, resulting in the soluble CD14 protein (sCD14). CD14 is down regulated from the cell membrane on stimulated monocytes by different factors such as LPS, IFNγ, PMA, calcium ionophore A 23187, and antibodies against CD14. CD14 can be released from the cells with GPI-phospholipase C and D (PLC/D). Membrane associated CD14 is a pro-inflammatory co-receptor for LPS, a characteristic constituent of the cell wall of Gram-negative bacteria. LPS interacts with LPS-binding protein (LBP) and CD14, and this complex interacts with TLR4, which subsequently induces inflammatory gene expression through NF-κB and mitogen-activated protein-kinase signaling in host cells. sCD14 enables responses to LPS by cells that do not express CD14 such as endothelial cells. In this sense, HUVEC cells respond to LPS by production of IL-6 and this responsiveness is serum dependent. Elevated levels of sCD14 has been detected in serum of patients with different diseases such as systemic lupus erythematosus, HIV infected patients, common variable immunodeficiency (CVID), and nonalcoholic fatty liver disease (NAFLD). Also, high levels of sCD14 have been associated with infectious diseases, including sepsis. In addition, it has been reported that sCD14 could be a potential biomarker for predicting the prognosis of breast invasive ductal carcinoma.Product Details
- Mouse CD14, amino acid (Ala18-Pro345) (Accession# Q4FJ97) was expressed in 293E cells.
- Molecular Mass
- The 328 amino acid recombinant protein has a predicted molecular mass of approximately 35.2 kD. The reduced and non-reduced protein migrates at approximately 50 kD by SDS-PAGE. The predicted N-terminal amino acid is Ala.
- >98%, as determined by Coomassie stained SDS-PAGE.
- 0.22 µm filtered protein solution is 1X PBS, pH 7.2.
- Endotoxin Level
- Less than 0. 1 EU/µg cytokine as determined by the LAL method.
- 10 and 25 µg sizes are bottled at 200 µg/mL. 100 µg 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.)
- Storage & Handling
- Unopened vial can be stored between 2°C and 8°C for one months, at -20°C for six months, or at -70°C for one year. For maximum results, quick spin vial prior to opening. Stock solutions should be prepared at no less than 100-200 µg/mL in sterile buffer (PBS, HPBS, DPBS, and EBSS) containing carrier protein such as 0.2 - 1% BSA or HSA. After dilution, the cytokine can be stored at 4°C for one month or from -20°C to -70°C for up to three months. Avoid repeated freeze/thaw cycles.
- The ED50 = 5 - 25 ng/mL, as determined by the inhibition of IL-8 production in THP-1 human acute monocytic leukemia cells in the presence of 10 ng/mL LPS.
- Application Notes
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 firstname.lastname@example.org.
Activated monocytes are a source of sCD14. It is present in plasma, colostrum, and milk.
- CD14 enhances innate immune responses to infections, and it sensitizes cells to bacterial LPS. sCD14 induces B cell growth and differentiation. It enables responsivesness to LPS by non CD14-expressing cells. LPS, IFNγ, PMA, calcium ionophore A 23187, and antibodies against CD14 induce sCD14.
- B cells, endothelial cells
- Ligand Receptor
- LBP, TLR2, TLR4
- Cell Type
- Dendritic cells
- Biology Area
- Immunology, Innate Immunity
- Antigen References
- Simmons DL, et al. 1989. Blood. 73:284.
- Wright SD, et al. 1990. Sciences. 249:1431.
- Bazil V and Strominger JL. 1991. J Immunol. 147:1567.
- Frey EA, et al. 1992. J Exp Med. 176:1665.
- Matsuguchi T, et al. 2000. J Immunol. 165:5767.
- Bochkov VN, et al. 2002. Nature. 419:77.
- Zanin-Zhorov A, et al. 2007. J Immunol. 179:41.
- Baumann CL, et al. 2010. J Exp Med. 207:2689.
- Litzman J, et al. 2012. Clin Exp Immunol. 170:321.
- Gene ID
- 12475 View all products for this Gene ID
- View information about CD14 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.