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Human IL-28A/IFN-Lambda 2, Carrier-Free

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Human IL-28A/IFN-Lambda 2, Carrier-Free

Catalog Number: 11821

Recombinant Human Interleukin 28A (IL-28A)/IFN-Lambda 2 expressed in mouse myeloma cell line, NS0-derived.


Pack Size

Formulation Supplied lyophilized without a carrier protein
Molecular Weight Based on N-terminal sequencing, the mature recombinant IL-28A starts at Val 26 and has a calculated molecular mass of 20.8 kDa. As a result of glycosylation, the recombinant monomer migrates as an approximately 24 kDa protein in SDS-PAGE under reducing conditions.
Source DNA sequence encoding human IL-28A with a carboxyl-terminal polyhistidine tag expressed in mouse myeloma cell line, NSO
Purity Greater than 95% as determined by a combination of HPLC methods
Endotoxin level < 1 EU/μg
Bioactivity Human HepG2 cells infected with encephalomyocarditis virus, ED50 ~10-50 ng/ml
Storage For retention of full activity store at -70°C or below and avoid repeated freeze/thaw cycles
Synonyms Hu IL-28A; Hu IFN-λ2
Accession Number


Tech Info & Data



IL-28A, IL-28B, and IL-29, also named interferon-λ2 (IFN-λ2), IFN-λ3, and IFN-λ1, respectively, are newly identified class II cytokine receptor ligands that are distantly related to members of the IL-10 family (11-13% aa sequence identity) and type I IFN family (15 - 19% aa sequence identity). The genes encoding these three cytokines are localized to chromosome 19 and each is composed of multiple exons. The exon organization of these genes is also found in the IL-10 family genes but is distinct from the type I IFNs, which are encoded within a single exon. The expression of IL-28A, B, and IL-29 is induced by virus infection or double-stranded RNA. All three cytokines exert bioactivities that overlap those of type I IFNs, including antiviral activity and up-regulation of MHC class I antigen expression. The three proteins signal through the same heterodimeric receptor complex that is composed of the IL-10 receptor β (IL-10 Rβ) and a novel IL-28 receptor α (IL-28 Rα, also known as IFN-λ R1). Ligand binding to the receptor complex induces Jak kinase activation and STAT1 and STAT2 tyrosine phosphorylation. The phosphorylated STAT1 and STAT2 complex with IFN-regulatory factor 9 (IRF-9) to form the IFN-stimulated regulatory factor 3 (ISGF-3) transcription factor complex that is translocated to the nucleus. ISGF-3 binds to the IFN-stimulated response element (ISRE) present in the regulatory regions of the target genes. Human IL-28A cDNA encodes a 200 amino acid (aa) residue precursor protein with a putative 25 aa signal peptide. It shares 94% and 67% aa sequence identity with human IL-28B and human IL-29, respectively.




  1. Vilcek, J., 2003, Nature Immunol. 4:8 - 9.

  2. Sheppard, P. et al., 2003, Nature Immunol. 4:63 - 68.

  3. Kotenko, S.V. et al., 2003, Nature Immunol. 4:69 - 77.


Certificate of Analysis (CoA) and Safety Data Sheet (SDS)
11821-1 CoA

11821-1 Certificate of Analysis (CoA)

11821 SDS

11821 Safety Data Sheet