Fig 1. US28 mediated signaling inhibits IE1 expression in monocytes.

(A to C) Primary human peripheral blood monocytes were mock-infected or infected (MOI = 1) with wild-type (WT) or US28Δ HCMV for 24 h (A, C) or 48 h (C). IE1 induction was detected by Western blot (A, C) and quantified (B). WT-infected primary human fibroblasts are shown as a positive control. (D) NuFF-1 cells were infected (MOI= 1) with US28-3xFLAG, R129A, or ΔN HCMV. After 100% cytopathic effect occurred, cell-free HCMV was purified from supernatants and cell lysates were collected. Incorporation of recombinant US28 into HCMV viral particles was detected by Western blotting for FLAG. IE1, pp65, and tubulin were used as controls. (E and F) Monocytes were mock-infected or infected with WT, US28Δ, ΔN or R129A HCMV (MOI = 1) for 24 h. IE1 induction was detected by Western blot (E) and quantified (F). β-actin was used as a loading control. Western blots and densitometry are representative of at least 3 biological replicates per group. *P<0.05, **P < 0.005, ****P < 0.0001, by one-way ANOVA with Tukey’s HSD post hoc test or Student’s t-test.