FIG 5.

Inhibition of TK autophosphorylation and virus production by kinase inhibitors in KSHV-infected cells. (A to D) iSLK cells stably transfected with KSHV BAC16 WT were induced with SB (1 mM) and doxycycline (1 μg/ml) and treated with 5 or 10 μM dasatinib (A), bosutinib (B), or ponatinib (C). Nonreactivated cells were used as a control. At 48 h after induction, cells were lysed, immunoprecipitated using beads coupled to an antibody against phosphorylated tyrosine residues, and analyzed by immunoblotting using antibodies against phosphorylated tyrosine residues (pY) and β-actin. (D) Supernatants from inhibitor-treated, reactivated and nonreactivated iSLK cells were used to infect HEK293. Infected GFP-positive cells were counted 48 h after infection. An unpaired t test was performed. ***, P < 0.001. (E) Dasatinib treatment of cells infected with KSHV-WT or the KSHV-3GV mutant. iSLK cells stably transfected with KSHV-WT (WT) or the 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 dasatinib. 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 cells. Infected GFP-positive cells were counted 48 h after infection.