FIG 3.

HCMV is able to efficiently induce a senescence-like phenotype in infected cells that have reduced levels of Rb. (A and B) Passage 6 fibroblasts were induced to undergo senescence by plating at a high density and maintenance in complete media for 48 h (A) or plated at a subconfluent density and serum-starved for 48 h before fixation and staining for senescence-associated β-galactosidase (SA-β-Gal, left) and Hoechst to visualize nuclei (right) (B). (C) HCMV-infected scrambled control cells were serum starved and infected at an MOI of 1, and at 72 h postinfection the cells were stained for SA-β-Gal and the percentages of positive cells were calculated. The horizontal bar represents the mean from three biological replicates, and the individual symbols represent the values from three biological replicates. A paired Student t test was used to evaluate statistical significance (not significant, P > 0.9). (D and E) Representative images of the SA-β-Gal staining of scrambled control (Scr) (D) or Rb knockdown (Rb2) (E) cells used to generate the results for panel C are shown.