Cholesterol depletion reduced BRV entry. MA-104 cells were pretreated with different concentrations of MβCD followed by BRV infection for 12 h. (A) The virus titers were determined by TCID50 assay. (B) Viral mRNA levels were measured by Realtime PCR, results are expressed as the fold increase relative to mock-treated control (set at 1.0). All experiments were performed three times, and the error bars indicated the standard deviations of three independent experiments. (C) After virus attachment, the unbound BRV was removed, cells were treated with MβCD at indicated time at 37°C. At 12 hpi, the levels of VP4 in the BRV-infected cells were detected by Western blotting.