Recombinant Human IFNa5 protein

Interferon alpha-5 (IFNα5), a member of the type I interferon family, is a naturally occurring cytokine critical in mediating innate immune responses against viral infections and modulating adaptive immunity. Discovered in the 1980s, human IFNα5 is encoded by the IFNA5 gene located on chromosome 9. It shares structural homology with other IFNα subtypes, featuring a conserved core fold stabilized by disulfide bonds, but exhibits unique receptor-binding affinities and functional specificities due to subtle amino acid variations.

Recombinant IFNα5 is produced using biotechnological platforms, typically through expression in Escherichia coli or mammalian cell systems. The non-glycosylated bacterial product or glycosylated mammalian-derived protein is purified to >95% homogeneity, ensuring bioactivity comparable to native IFNα5. Its molecular weight ranges between 19-20 kDa depending on the expression system.

Functionally, IFNα5 activates the JAK-STAT signaling pathway by binding to the IFNAR1/IFNAR2 receptor complex, inducing interferon-stimulated genes (ISGs) that establish antiviral states in cells. Preclinical studies highlight its potent antiviral activity against hepatitis B/C viruses and herpesviruses, often exceeding other IFNα subtypes in specific contexts. It also demonstrates immunomodulatory effects, enhancing antigen presentation and T-cell responses, which underpins its exploration in cancer immunotherapy, particularly for hematologic malignancies.

Clinically, while IFNα2 remains the most therapeutically utilized subtype, IFNα5 has gained attention for its distinct pharmacokinetic profile and reduced toxicity in early-phase trials. Current research focuses on engineering PEGylated variants to extend half-life and evaluating synergistic effects with checkpoint inhibitors. Its role in autoimmune diseases and as a vaccine adjuvant is also under investigation, reflecting the expanding therapeutic potential of recombinant IFNα5.