IRF7 is a key transcriptional factor involved in the signaling pathway leading to establishment of antiviral state in infected cells. Under normal conditions, IRF7 exists in a latent form in the cytoplasm. Viral infection triggers the phosphorylation of IRF7 C-terminal region. The activated IRF7 migrates to the nucleus leading to the transcriptional activation of the IFN-alpha and IFN-beta genes. IRF7 is predominantly expressed in the spleen, thymus and primary blood lymphocytes(PBL) as a lymphoid-specific factor.
Several viral proteins interfere with IRF7 activity thus modulating the response to the virus induced in the infected cell. For example, VP35 from ebola virus exploits the cellular SUMOylation machinery for its advantage and increase IRF7 SUMOylation thereby disabling its activity.