Synonyms
Interleukin 28A;Interferon lambda-2;Interleukin-28A;IFN-lambda-2
Description
IL28A (Interferon-lambda 2; IFN-lambda 2), IL-28B/IFN-lambda 3, and IL-29/IFN-lambda 1 are type III interferons which are distantly related to IL-10 family and type I IFN family cytokines. Mature human IL-28A is an approximately 22-25 kDa protein that shares 66% amino acid (aa) sequence identity with mouse and rat IL-28A and shows cross-species activity. It shares 96% and 70% aa sequence identity with human IL-28B and IL-29, respectively. Type III interferons are upregulated in response to viral infection, and they act predominantly on epithelial cells through a receptor complex that contains IL-10 R beta and IL-28 R alpha /IFN-gamma R1. Type III IFNs function as anti-viral molecules and induce the upregulation of MHC class I antigen. IL-28A promotes the Th1 polarization of dendritic cells in the airway (e.g. production of IL-12 p70 and IFN-gamma ) and inhibits Th2 and Th17 mediated inflammation. In the liver, however, the IL-28A induced Th1 cytokine response contributes to inflammation in T cell mediated hepatitis. IL-28A additionally exhibits anti-tumor activity, in part by enhancing IL-12 dependent anti-tumor CTL responses in vivo. In contrast, it is up-regulated in invasive bladder cancer where it promotes tumor cell migration.
Molecular Weight
Approximately 19.7 kDa.
AA sequence
DPVPRATRLP VEAKDCHIAQ FKSLSPKELQ AFKKAKDAIE KRLLEKDMRC SSHLISRAWD LKQLQVQERP KALQAEVALT LKVWENMTDS ALATILGQPL HTLSHIHSQL QTCTQLQATA EPKPPSRRLS RWLHRLQEAQ SKETPGCLED SVTSNLFRLL TRDLKCVASG DQCV
Appearance
Sterile Filtered White lyophilized (freeze-dried) powder.
Purity
> 95 % by SDS-PAGE and HPLC analyses.
Biological Activity
Fully biologically active when compared to standard. The ED50 as determined by an anti-viral assay using human HepG2 cells infected with encephalomyocarditis is less than 3 ng/ml, corresponding to a specific activity of > 3.3 × 105 IU/mg.
Endotoxin
< 0.1 EU per 1μg of the protein by the LAL method.
Formulation
Lyophilized from a 0.2 µm filtered concentrated solution in PBS, pH 7.4, with 5 % trehalose.
Reconstitution
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1 % BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20 °C. Further dilutions should be made in appropriate buffered solutions.