Type I and Type II interferon signaling pathways (IFN pathways) (IFN pathways)

The Type I and Type II interferon (IFN) signaling pathways are fundamental components of the immune system that mediate cellular responses to viral infections, bacterial pathogens, and tumors (Ivashkiv & Donlin, Nature Reviews Immunology, 2014). Type I interferons, such as IFN-α and IFN-β, bind to the ubiquitous IFNAR1/IFNAR2 receptor complex, activating Janus kinases (JAK1 and TYK2) to induce a broad antiviral state through the expression of interferon-stimulated genes (Platanias, Nature Reviews Immunology, 2005). Type II interferon, or IFN-γ, binds to the IFNGR1/IFNGR2 complex, primarily activating JAK1 and JAK2 to promote macrophage activation, antigen presentation, and Th1 cell differentiation (Schreiber, Journal of Biological Chemistry, 2017). Dysregulation of these pathways is central to the pathogenesis of autoimmune disorders like systemic lupus erythematosus, where chronic Type I IFN signaling drives tissue damage, and hemophagocytic lymphohistiocytosis, which is driven by excessive Type II IFN (NIH, StatPearls: Interferon, 2023). Therapeutic interventions include receptor-blocking antibodies like anifrolumab for lupus, neutralizing antibodies like emapalumab for HLH, and various JAK inhibitors that dampen downstream signaling (FDA, Saphnelo Prescribing Information, 2021). Conversely, recombinant interferons are utilized as therapeutic agonists to treat chronic viral hepatitis and certain malignancies by leveraging their potent antiproliferative and immunomodulatory effects.

Other names

Type I IFN pathwayType II IFN pathwayIFN-alpha/beta signalingIFN-gamma signalingJAK-STAT interferon signaling

Modulation of interferon signaling through receptor antagonism, cytokine neutralization, or inhibition of downstream Janus kinases (JAKs).