Host interferon pathway (IFN pathway)

The host interferon (IFN) pathway is a complex signaling network essential for the innate immune response against viral, bacterial, and parasitic pathogens (StatPearls, 2023). It is classified into three main types: Type I (IFN-alpha, IFN-beta), Type II (IFN-gamma), and Type III (IFN-lambda), each utilizing specific cell-surface receptors to trigger intracellular cascades (Nature Reviews Immunology, 2019). Signaling typically proceeds through the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, resulting in the expression of hundreds of interferon-stimulated genes (ISGs) that inhibit viral replication and modulate immune cell activity (PubMed, 2020). While vital for defense, chronic or excessive activation of this pathway is a hallmark of autoimmune diseases such as systemic lupus erythematosus and certain autoinflammatory interferonopathies (NIH, 2022). Therapeutically, the pathway is targeted by recombinant interferons to treat viral hepatitis and cancers, or by inhibitors like anifrolumab and JAK inhibitors to dampen overactive immune responses in inflammatory conditions (PubChem, 2023). Management of these therapies is often complicated by significant side effects, including severe flu-like symptoms and potential neuropsychiatric issues (Mayo Clinic, 2023).

Other names

Interferon signaling pathwayIFN signaling cascadeType I, II, and III interferon pathwaysInterferon-mediated immune response

The pathway is modulated via several mechanisms: direct activation using recombinant interferon receptor agonists to induce antiviral and antiproliferative states; blockade of interferon receptors (e.g., IFNAR1) using monoclonal antibodies to reduce pathological signaling in autoimmune diseases; and inhibition of downstream Janus kinases (JAK1/JAK2/TYK2) to prevent the transcription of interferon-stimulated genes (ISGs).