FIGURE 7.

HCMV IE86 protein interferes with 2′3′-cGAMP-induced signaling pathway. (A) HEK293T cells were co-transfected with small amounts of vectors expressing STING and control renilla luciferase reporter and IFN-β promoter-driven firefly luciferase reporter plasmids plus the expression vector for IE72, IE86 or UL82. At 18 h after transfection, cells were treated with a STING agonist, 2′3′-cGAMP, and IFN-β promoter-driven luciferase activities were determined at 12 h after treatment. (B) HEK293T cells were transfected with the vector expressing STING plus the expression vector for GST, GST-IE72, GST-IE86 or GST-UL82. At 24 h after transfection, cells were harvested, and equal amounts of cell extracts were subjected to western blot analysis with antibodies to STING, TBK1, GST and tubulin. (C) HFF cells were transduced with 10 pfu per cell of either Ad-GFP plus Ad-Trans or Ad-IE86 plus Ad-Trans. At 48 h after transduction, cells were treated with 2′3′-cGAMP, and relative amounts of IFNB1, CXCL10 and UL122 transcripts were measured using qRT-PCR at 12 h after treatment. The data shown here represent three independent experiments ±SD. The asterisk (^∗) denotes a significant difference between samples, which was determined by the P-value of a two-sample t-test (P < 0.05).