Fig. 2.

Effects of viral cholesterol depletion on the replication of porcine nidoviruses. (A) PRRSV and PEDV stocks were pretreated with MβCD to remove cholesterol in the viral envelope, followed by ultracentrifugation. Virion cholesterol content was determined using the cholesterol-binding, fluorescing antibiotic filipin III. Fluorescence intensity was measured using a fluorescence microplate reader. (B) PAM-pCD163 and Vero cells were infected with the purified PRRSV and PEDV, respectively. At 48 hpi, the virus-infected cells were fixed, and virus infectivity was determined by measuring the percentage of cells expressing N proteins of PRRSV or PEDV by FACS. (C) Culture supernatants were harvested at the same time point, and the titers of PRRSV and PEDV were measured. The values are representative of three independent experiments, and error bars indicate standard deviations