FIG 3 .

Ectopic US28 expression in THP-1 cells can complement for a deletion of US28 from the virus. THP-1 cells stably expressing N-terminally HA-tagged US28 (HA-US28-WT), US28 with a disrupted G protein binding DRY motif (HA-US28-R129A), and US28 with a disrupted chemokine binding region (HA-US28-Y16F) were generated by lentiviral transduction and puromycin selection. (A) Western blot analysis using an antibody against the N-terminal HA tag was carried out on an empty-vector-transduced cell line and the three cell lines expressing HA-US28 constructs. (B) These THP-1 cells, expressing different HA-US28 constructs and empty vector control cells, were infected with Titan-ΔUS28 and fixed 5 days postinfection. Fixed samples were stained for immediate early or UL32-GFP and nuclei were also stained. (C) Media from these infected cells was titrated on indicator fibroblasts and the number of infectious virions quantified by IE staining. Data are means of results from at least three independent experiments; error bars show standard deviations.