Interferon alpha (IFN-α) (IFN-α)

Interferon alpha (IFN-α) is a group of Type I interferon cytokines produced primarily by plasmacytoid dendritic cells (pDCs) in response to the activation of pattern recognition receptors like TLR7 and TLR9 (Source: UniProt P01562). It functions by binding to the heterodimeric IFN-α/β receptor (IFNAR), which triggers the JAK-STAT signaling pathway to induce the expression of hundreds of interferon-stimulated genes (ISGs) that mediate antiviral, antiproliferative, and immunomodulatory effects (Source: PubMed PMID: 30559446). In oncology and virology, recombinant IFN-α (e.g., Interferon alfa-2b) is used to enhance the immune response against tumors and viruses like Hepatitis B and C (Source: PubChem CID: 11966181). However, chronic overproduction of IFN-α is a hallmark of autoimmune disorders such as systemic lupus erythematosus (SLE), where it promotes the maturation of myeloid dendritic cells and the loss of self-tolerance (Source: NIH/NCBI Bookshelf NBK482395). Consequently, therapeutic interventions include monoclonal antibodies that neutralize IFN-α (e.g., sifalimumab) or block its receptor (e.g., anifrolumab) to reduce disease activity in SLE patients (Source: FDA Label for Saphnelo). The term "IFN-α production" refers to the biological process of cytokine synthesis rather than a specific molecular target, making it an imprecise descriptor for a drug target.

Other names

IFN-alphaType I InterferonLeucocyte interferonIFNAIFNA1IFNA2

Interferon alpha acts as an agonist by binding to the IFNAR1/IFNAR2 receptor complex, which activates the receptor-associated kinases JAK1 and TYK2. This leads to the phosphorylation of STAT1 and STAT2, which dimerize and associate with IRF9 to form the ISGF3 complex, translocating to the nucleus to initiate transcription of interferon-stimulated genes. Therapeutic antibodies like sifalimumab neutralize the cytokine directly, while anifrolumab blocks the IFNAR1 subunit, both preventing the initiation of this signaling cascade in autoimmune conditions.