Interferon
A family of signalling proteins released by cells in response to viral infection, activating antiviral defences in neighbouring cells. Interferons also modulate immune responses and have anti-tumour properties. Interferon biology intersects with peptide therapeutics in hepatitis treatment where thymosin alpha-1 is used.
Technical Context
IFN types: Type I (IFN-α from leukocytes, IFN-β from fibroblasts — induced by viral infection, activating antiviral gene programme via JAK1-TYK2/STAT1-STAT2/IRF9 signalling), Type II (IFN-γ from T cells and NK cells — activating macrophages for intracellular pathogen killing via JAK1-JAK2/STAT1 signalling), Type III (IFN-λ — mucosal antiviral immunity). Thymosin alpha-1's mechanism involves enhancing IFN-α production by plasmacytoid dendritic cells (through TLR9 activation) — this is the rationale for its use as adjunct to interferon therapy in hepatitis B/C. Glatiramer acetate may also modulate IFN-γ production — shifting from IFN-γ-dominant Th1 responses (pro-inflammatory in MS) toward IL-4/IL-10-dominant Th2 responses (anti-inflammatory). IFN-β (Avonex, Rebif, Betaferon) is itself a protein therapeutic used in MS — it reduces relapse rate by approximately 30%, comparable to glatiramer acetate.