Avian oncogenic herpesvirus antagonizes the cGAS-STING DNA-sensing pathway to mediate immune evasion
Fig 5
Meq interacts with STING and IRF7.
(A) The IFN-β-luc, IRF7-luc, or NF-κB-luc reporter was cotransfected with cGAS and STING constructs as well as Meq-Flag plasmid or empty vector into DF-1 cells. After 36 h, cells were harvested and analyzed using the dual-luciferase reporter assay. (B) DF-1 cells were transfected with cGAMP or plasmid expressing TBK1 or IRF7, together with IFN-β-luc reporter and Meq-Flag plasmid or an empty vector. The dual-luciferase reporter assay was performed 36 h posttransfection, and the fold relative to the mock controls was determined. (C) HEK293T cells were transfected with the indicated plasmids for 36 h before coimmunoprecipitation and immunoblot analysis with the indicated antibodies. (D) Coimmunoprecipitation and immunoblot analyses were performed with the endogenous proteins from the CEFs left uninfected or infected with MDV. (E) Purified GST, GST-STING, or GST-IRF7 were used to pull down transiently expressed Meq-Flag as indicated. (F) Full length Meq (Meq-FL), and N- (Meq-N) or C-terminally truncated forms of Meq (Meq-C) were transfected together with STING-HA or IRF7-HA plasmids into HEK293T cells for 36 h before coimmunoprecipitation and immunoblot analysis with the indicated antibodies. (G) DF-1 cells were transfected with IFN-β-luc reporter, and expression plasmids for cGAS, STING, IRF7, Meq, and its truncation mutants for 36 h before luciferase assays. ***: p < 0.001; ns: no significant difference.