Interferon (IFN)

Interferons (IFNs) are a family of naturally occurring cytokines secreted by immune cells in response to pathogens such as viruses, bacteria, or tumor cells [1]. They are categorized into three main types: Type I (e.g., IFN-alpha, IFN-beta), Type II (IFN-gamma), and Type III (IFN-lambda), each signaling through distinct receptor complexes to activate the JAK-STAT pathway [2][3]. These proteins play a critical role in the innate immune response by inducing an antiviral state in cells, inhibiting viral replication, and enhancing the activity of natural killer cells and macrophages [1][4]. Clinically, recombinant interferons are used as therapeutic agents for treating chronic viral hepatitis, certain malignancies like melanoma, and autoimmune conditions like multiple sclerosis [2][5]. Conversely, dysregulated interferon signaling is a hallmark of interferonopathies and systemic lupus erythematosus, where therapeutic strategies involve neutralizing the cytokines or blocking their receptors [3][6].

Other names

IFNsType I interferonType II interferonType III interferonAntiviral proteinInterferon receptor

Interferons bind to specific multi-subunit receptors on the cell surface (IFNAR for Type I, IFNGR for Type II, and IFNLR for Type III), triggering the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway [1][3]. This signaling cascade leads to the phosphorylation and nuclear translocation of STAT proteins, which induce the expression of interferon-stimulated genes (ISGs) that mediate antiviral, antiproliferative, and immunomodulatory effects [3][4].