ER stress induces late events in EBV lytic production. (A-B). TG treatment results in gp350 expression at the plasma membrane. Five days after chemical treatment, LCLs were stained for gp350 and analyzed by flow cytometry. The percentage of gp350-positive cells is plotted (A). The shift in fluorescence intensity of gp350-positive cells from DMSO-treated (pink trace) to TG-treated (green trace) LCLs can be seen (B). The background fluorescence of LCLs is shown as the filled trace. (C) TG treatment results in increased EBV copy number in high-copy-number LCLs (> 400 episomes/cell). Five days after chemical treatment of LCLs, supernatant was collected and EBV copy number determined by qPCR. (D) TG treatment does not increase EBV copy number in low-copy-number LCLs (< 50 episomes/cell). Five days after chemical treatment of LCLs, supernatant was collected and EBV copy number determined by qPCR. (E) Induction of EBV lytic genes 5 days after chemical treatment, when LCLs were harvested, RNA isolated, and gene expression of immediate-early (BRLF1 and BZLF1), early (BMRF1), and late (gp350) EBV lytic genes was evaluated by real-time qPCR.