Figure 4

HSP90 inhibitors prevented the viral RNA synthesis. PRRSV-infected cells were treated with chemicals at the concentration as indicated. Mock-infected cells were untreated. (A) MARC-145 cells and (B) PAMs were harvested at 24 h.p.i. Total RNA was isolated and strand-specific qRT-PCR was performed to determine the viral full-length minus-stranded RNA copy number. Data are mean ± SD, n = 3, and significant differences compared with DMSO (in MARC-145 cells) or no drug (in PAMs) treatment group, respectively, are denoted by ^*(P < 0.05). (C) Inhibitors-treated MARC-145 cells were fixed at 24 h.p.i to detect viral dsRNA (red) by IFA. Nuclei were stained with Hoechst dye 33258 (blue). Bar, 50 μm.