IRF3 and infection: Indeed, the co-expression of a dominant-negative of IRF3 corresponding to the C-terminal part of the protein (IRF3 Cter; amino acids 115 to 449; GenBank accession no. HE856621) together with STING or MAVS abolished the protection as shown by the apparition of a complete CPE 3 days post-infection (Figure 5A) and a massive virus production (Figure 5B).