Fig. 4.

Deletion of the UL133 to UL138 genes is sufficient to reinstall the inhibition of TNF-α-induced NF-κB activation by HCMV. (A) Schematic illustration of Toledo knockout mutants within the ULb′ region. UL133 to UL151 genes were grouped and deleted in 5 sets from the Toledo BAC as indicated. UL130 to UL132 were not included, since these genes are present in both AD169-varATCC and AD169-varT and should therefore not account for the functional differences of these strains. (B) Primary fibroblasts were infected with Toledo knockout mutants as indicated for 72 h and either treated (+) or not treated (−) with TNF-α. NF-κB DNA binding was detected by EMSA. (C) Quantitative analysis of three independent EMSA experiments by phosphorimaging. (D) Surface expression of TNFR1 on control cells and cells infected with HCMV as indicated was performed as described for Fig. 3D.