Recombinant human IFN-α2b

IFN-α signaling

Recombinant human interferon-alpha 2b (with HSA)

The human interferon α2 (hIFN-α2) was the first highly active IFN subtype to be cloned and available for research.  For this reason, hIFN-α2 has been the prototypic IFN-α among all other subtypes of this family used in fundamental research and most clinical applications [1, 2].

 More details

Human IFN-α2a and-α2b are allelic variants differing by a neutral lysine to arginine substitution at position 23 of the mature protein, respectively [1, 2].  They are the only IFN-α subtypes with an O-glycosylation site (on Thr106) [2]. Human IFN-α2b is induced in peripheral blood mononuclear cells (PBMCs) upon incubation with CpG-oligonucleotides and in plasmacytoid dendritic cells upon incubation with CpG-oligonucleotides or imiquimod [1, 2]. All IFN-αs bind to a common heterodimer receptor IFNAR1/IFNAR2. The ternary complex signals through the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) signaling pathway, inducing the formation of the ISGF3 transcriptional complex (STAT1/STAT2/IRF9). ISGF3 binds to IFN-stimulated response elements (ISRE) in the promoter regions of numerous IFN-stimulated genes (ISGs) [3].

InvivoGen provides a glycosylated recombinant human IFN-α2b that is produced in CHO cells (as opposed to recombinant IFN-αs produced in non-mammalian cells). Of note, glycosylation stabilizes proteins against physicochemical instabilities.

Key features:

• Produced in CHO cells
• High-quality: purity ≥ 95% and endotoxin level < 1EU/µg
• Functionally tested

Applications:

• Cellular assays
• ELISA

IFN-α2b provided by InvivoGen is for research use only.

References

1. Paul F. et al., 2015. IFNA2: The prototypic human interferon. Gene. 
2. Antonelli G. et al., 2015. Twenty-five years of type I interferon-based treatment: A critical analysis of its therapeutic use. Cytokine Growth Factor Rev. 26(2):121-31.
3. Schreiber G. 2017. The molecular basis for differential type I interferon signaling. J. Biol. Chem. 292:7285-94.

Figures

Dose-response of IRF-reporter cells to recombinant IFN-α2b.
HEK-Blue™ IFN-α/β cells (A) or THP1-Dual™ cells (B) were stimulated with increasing concentrations of recombinant human IFN-α2b. After overnight incubation, ISG activation was assessed by measuring SEAP activity (A) or Lucia luciferase activity (B) in the supernatant using QUANTI‑Blue™ Solution and QUANTI‑Luc™ detection reagents, respectively.

Specifications

Source: Mammalian; Chinese hamster ovary (CHO) cells

Uniprot ID: P01563

Alternate name: IFN-alpha 2

Formulation: Lyophilized from a 0.2 µm filtered phosphate buffer solution (pH 7.4) containing 2% human serum albumin (HSA) and 5% saccharose.

Molecular mass: ~ 21 kDa (SDS-PAGE)

Solubility: 100 μg/ml in water

Quality control:

   Purity: ≥95% (SDS-PAGE)
   Endotoxin level: ≤ 1 EU/μg
   The biological activity has been confirmed using HEK-Blue™ IFN‑α/β cells (see validation data sheet).
   The units have been determined for each lot using hIFN-α2 laboratory standard calibrated to the WHO International Standard Interferon Alpha (Human leukocyte-derived) from the National Institute for Biological Standards and Control (NIBSC; code 94/784) [*]

* http://www.nibsc.org/documents/ifu/94-784.pdf. National Institute for Biological Standards and Control. Potters Bar, Hertfordshire, EN6 3QG. WHO International Laboratory for Biological Standards. UK Official Medicines Control Laboratory.

Contents

• 1 μg of lyophilized recombinant human IFN-α2b.
• 1.5 ml endotoxin-free water.

Recombinant human IFN-α2b is shipped at room temperature.

Upon receipt it should be stored at -20°C.

Details

The human interferon-alpha family

Type I interferons (IFN) include the IFN-α family, IFN-β, IFN-ε, IFN-κ, and IFN-ω. IFN-αs are important anti-viral cytokines that also have anti-proliferative and immuno-modulatory functions. The human IFN-α family comprises 13 genes encoding 12 proteins, with IFN-α13 being identical to IFN-α1. All IFN-αs bind to a common heterodimer receptor IFNAR1/IFNAR2. The ternary complex signals through the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) signaling pathway, inducing the formation of the ISGF3 transcriptional complex (STAT1/STAT2/IRF9). ISGF3 binds to IFN-stimulated response elements (ISRE) in the promoter regions of numerous IFN-stimulated genes (ISGs) [1].

Human IFN-α genes have evolved under strong selective pressure, suggesting a non-redundant role between IFN-α subtypes [2]. Although most studies have focused on IFN-α2 and IFN-α8, a consensus model for all IFN-αs has emerged depending on the affinity of a particular IFN-α subtype for IFNAR. Low-affinity IFN-α subtypes signal strictly through ISGF3 and induce robust ISGs, such as PKR, ISG56, and IFI16, which display anti-viral functions. Conversely, high-affinity IFN-α subtypes signal through ISGF3 and other factors, which activate “tunable” ISGs” such as CXCL10, IL-8, and ISG15, that induce anti-proliferative and immuno-modulatory functions [3]. IFN-α8, IFN-α10, and IFN-α14 have been identified as the most potent inducers of ISGs, while IFN-α1 is the weakest [4].

IFN-α subtypes available upon request for a minimum quantity

1. Schreiber G. 2017. The molecular basis for differential type I interferon signaling. J. Biol. Chem. 292:7285-94.
2. Manry J. et al., 2011. Evolutionary genetic dissection of human interferons. J. Exp. Med. 208:2747-59.
3. Levin D. et al., 2014. Multifaceted activities of type I interferon are revealed by a receptor antagonist. Sci. Signal. 7(327). ra50.
4. Kurunganti S. et al., 2014. Production and characterization of thirteen human type-I interferon-α subtypes. Protein Expr. Purif. 103: 75-83.