Avian oncogenic herpesvirus antagonizes the cGAS-STING DNA-sensing pathway to mediate immune evasion
Fig 9
Schematic model of Meq-mediated inhibition of the cGAS-STING pathway during MDV infection.
MDV DNA or tumor-derived DNA is recognized by cytosolic DNA sensor cGAS, which produces cGAMP for STING activation and IFN-β production. However, the MDV oncoprotein Meq interacts with STING and IRF7, which disrupts assembly of the STING-TBK1-IRF7 complex, thereby leading to the inhibition of IRF7 activation and IFN-β induction during MDV infection. Additionally, STING is involved in the melanoma differentiation-associated gene 5 (MDA5) signaling pathway against RNA viruses as well as the innate immunity against bacteria. As an inhibitor of the cGAS-STING signaling, Meq could exert its immunomodulatory functions in the innate immune responses against not only DNA viruses but also RNA-related pathogens and various bacteria.