IL-28A (also named interferon-A2, IFN-A2), IL-28B (IFN-A3) and IL-29 (IFN-A1) are type III interferons that are class II cytokine receptor ligands.1-4 They are distantly related to members of the IL-10 family and type I IFN family.1-4 Mouse IL-28A cDNA encodes a 193 amino acid (aa) protein with a 19 aa signal peptide and a 174 aa mature protein that lacks N-glycosylation sites. Mature mouse IL-28A shares 81% and 66% aa sequence identity with rat and human IL-28A, respectively, and functions across species.5 Mouse IL-28A and IL-28B share 97% aa identity; the mouse lacks a functional IL-29 gene.4 Type III interferons are widely expressed, but are mainly produced by antigen presenting cells in response to viruses and double-stranded RNA that interact with Toll-like receptors or RIG-1 family helicases.2-6 They signal through a widely expressed receptor that is a heterodimer of the IL-10 receptor b (IL-10 Rb) and IL-28 receptor a (IL-28 Ra; also called IFN-lambda R1).2, 3, 7, 9 Interaction of either type I or type III IFNs with their receptors activates similar pathways, including JAK tyrosine kinase activation, STAT phosphorylation and formation of the IFN-stimulated regulatory factor 3 (ISGF-3) transcription factor complex.1-3 Both type I and III IFNs induce antiviral activity and upregulate MHC class I antigen expression.2-6 Cell lines responsive to type III IFNs are also responsive to type I IFNs, but in general, higher concentrations of type III IFNs are needed for similar in vitro responses.8 In vivo, however, type III IFNs enhance levels of IFN-y in serum, suggesting that the robust antiviral activity of type III IFNs may stem in part from activation of the immune system.5, 7 Anti-proliferative and antitumor activity in vivo has also been shown for type III IFNs.9-11
A DNA sequence encoding mouse IL-28A (Met 1-Val 193; Accession # Q4VK74) was fused with a six-histidine tag at the C-terminus. The protein was expressed in a mouse myeloma cell line, NS0.
Calculated molecular mass of 20. kD. As a result of glycosylation, the recombinant mouse IL-28A migrates as an ~ 25-30kD protein in SDS-PAGE under reducing conditions.
Activity:Measured in an anti-viral assay using human HepG2 cells infected with encephalomyocarditis virus.
Storage and Stability:Lyophilized and reconstituted products are stable for 6 months after receipt at -20°C. Reconstitute with sterile PBS. Aliquot to avoid repeated freezing and thawing. Store 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：25ug
Source Antigen：Recombinant, NS0 cells
Grade：Highly Purified
Purity：≥ 95%, as determined by SDS-PAGE under reducing conditions and visualized by silver stain. Endotoxin: ≤1EU/1ug.
Form：Supplied as a lyophilized powder in PBS. Reconstitute with 250ul sterile PBS.
