Progeny Varicella-Zoster Virus Capsids Exit the Nucleus but Never Undergo Secondary Envelopment during Autophagic Flux Inhibition by Bafilomycin A1

Girsch, James H.; Walters, Katherine; Jackson, Wallen; Grose, Charles

Titers of VZV in cultures treated with bafilomycin. Based on the appearance of the monolayer after BAF treatment, along with the decreased gE production, we predicted that the VZV titer in treated infected cells would be lower than the titer in untreated infected cells. To carry out the titrations, we sonically disrupted the cells in the infected monolayer after a 3-day incubation to obtain cell-free VZV. Following this procedure, the infectivity of the sonicate was titrated by 10-fold dilutions (Fig. 3 ). There was a marked drop in titer in the infected monolayer treated with BAF for 24 h, in other words, from 48 to 72 hpi. The differences in titers between a treated and an untreated monolayer were significant. When the monolayer incubated with BAF for 48 h (24 to 72 hpi) was sonicated and titrated, no infectious cell-free virus was recovered (Fig. 3 ). Because the decrease in infectivity after BAF treatment was substantial while the confocal microscopy experiments shown in Fig. 2 failed to reveal an explanation, we decided to examine the BAF-treated infected cells by electron microscopy.