Fig. 6.

US7 and US8 suppress innate antiviral response in vivo. a Schematic representation of the HCMV strains used. HCMV WT, wild-type HCMV AD169; HCMVΔUS7-16, HCMV deletion mutant lacking the US7-US16 region; HCMVΔUS7-16-Rev.US7 or -Rev.US8 HCMV mutant lacking all genes in the US7-US16 region restored with US7 or US8 expression. b, c HCMV, but not HCMVΔUS7-16, blocks antiviral response through destabilizing TLR3 and TLR4 proteins. HFF cells were infected with HCMV WT or HCMVΔUS7-16 at an MOI of 2 for the indicated times. The presence of HCMV-derived US7 or US8 and ifnb mRNA expressions were analyzed by RT-PCR. UL44 and GAPDH were used as HCMV infection and loading controls, respectively. d HCMV, but not HCMVΔUS7-16, degrades TLR3 and TLR4 proteins at late times. TLR3-Myc- or TLR4-Myc-expressing HFF cells were infected with HCMV WT or HCMVΔUS7-16 and the lysates were immunoblotted with indicated antibodies. RT-PCR analysis of UL44 and GAPDH was used as HCMV infection and loading controls, respectively. e US7 and US8 decreases TLR3 or TLR4 expression levels in vivo. HFF cells were infected with HCMV WT, HCMVΔUS7-16, HCMVΔUS7-16-Rev.US7, or HCMVΔUS7-16-Rev.US8. Lysates were immunoblotted with anti-TLR3, anti-TLR4, anti-GFP, anti-Calnexin, or anti-Tubulin antibody. RT-PCR analysis of UL44 and GAPDH was used as HCMV infection and loading controls, respectively. The intensity of TLRs bands was quantified as comparing the relative abundance of TLR3 or TLR4 to Tubulin (right graphs). f Both US7 and US8 block innate antiviral response in vivo. HFF cells were infected with HCMV WT, HCMVΔUS7-16, HCMVΔUS7-16-Rev.US7, or HCMVΔUS7-16-Rev.US8. The indicated gene expression was measured by qPCR. *P < 0.001, **P < 0.05 (Student’s t-test). Data are representative of three independent experiments and are presented as means ± s.d. in f. Source data are provided as a Source Data file