FIG 4.

USP9X knockdown reduces viral replication and infectivity of KSHV. (A) siRNA-transfected iSLK.219 cells were harvested 72 h postreactivation and gene expression was quantified with RT-qPCR. (B) Protein expression was determined by Western blotting at 72 h postreactivation. (C) iSLK.219 cells were either transfected with nonspecific siRNA (si NS) or USP9X siRNAs (si USP9X) for 48 h and viral reactivation was induced with doxycycline. Supernatants were harvested at 72 h postreactivation and virions were quantified by qPCR. (D) Supernatants were harvested at 72 h postreactivation and transferred to naive HEK293T. Fluorescence microscopy of GFP-positive HEK 293T cells infected with KSHV from the experiment described in panel A was conducted. (E) Quantification of GFP-positive cells by flow cytometry. Data are presented as mean ± standard deviation from at least three independent experiments. Significance was determined using ANOVA with multiple comparisons.