Fig 4.

Disrupting stem loop 1 decreases HCMV replication. (A) MRC5 fibroblasts were infected with equivalent number so viral genomes for each mutant as in Fig. 3. Viral protein expression for representative immediate early (IE1 and IE2), early (UL44), and late (UL99) proteins was measured by Western blot at the indicated times after infection. Representative results from three independent experiments are shown. (B) Cell-free virus was measured at 72, 96, and 120 hours after infection with each virus using the TCID₅₀ method. (C) Cell-free HCMV genomes were quantified at the indicated times after infection by qPCR. Results show the SEM for three independent experiments. Statistical significance was determined by pairwise comparison to WT values. All experiments were confirmed with two independent clones of each recombinant virus (*P < 0.05, **P < 0.01, multiple comparison statistics calculated using Dunnett’s test).