Figure 1.

Interferon and activation of classical JAK-STAT pathways by type I and III interferons. The type I and III IFN receptors are both associated with the Janus activated kinase 1 (JAK1). Activation of JAK1 results in tyrosine phosphorylation of STAT1 (signal transducer and activator of transcription) and STAT2, which leads to the formation of complexes that translocate to the nucleus and bind IFN-stimulated response elements (ISREs) in DNA to initiate gene transcription. Gene transcription then produces mRNA of interferon-stimulating genes (ISGs), including ISG56 (IFIT1), ISG54 (IFIT2), Viperin (gene name RSAD2), and ISG15. While functionally distinct, these ISGs collaborate to reduce viral replication. Created using BioRender (biorender.com; BioRender, Toronto, Ontario, Canada).