FIG 2.

ORF21 is required to activate brivudine (Briv) and zidovudine (Zido). (A and B) iSLK cells stably transfected with KSHV-WT (WT) or KSHV-ORF21_3GV mutant (3GV) were induced with SB (1 mM) and doxycycline (1 μg/ml) and treated with 0.01 μM to 10 μM (1/2 dilutions) of brivudine (A) or zidovudine (B) DMSO-treated nonreactivated and reactivated cells were used as a control. Supernatants from inhibitor-treated, reactivated, and nonreactivated iSLK cells were used to infect HEK293. Infected GFP-positive cells were counted 48 h after infection. (C and D) MTT assay of iSLK cells was performed 48 h after treatment with inhibitors and reactivation.