Virus Induced Signaling to Initiate the Interferon Mediated Anti-Viral Host Response

Signaling cascades leading to the activation of an anti-viral host response have been subject to intense investigations over the last decade. Consequently our understanding of the initial switches that launch this response have increased greatly. The establishment of an anti- viral state hinges on the co-ordinated production of type I interferons. These cytokines link the innate and adaptive anti-viral response. The expression of “early phase” interferons, comprising IFNß, murine IFNα4 or human IFNα1, are controlled by Toll-like receptor-induced signaling cascades that activate the latent transcription factors NF-кB and interferon regulatory factor (IRF)-3. In turn, the early IFNs induce signals to promote the expression and activation of transcription factors. These go on to induce the expression of a variety of cytokines and chemokines that propel cells of the adaptive immune system towards an anti-viral response.