Fig. 6.

Effects of cellular cholesterol depletion on virus entry. PAM-pCD163 and Vero cells were infected with PRRSV or PEDV at an MOI of 1 at 4 °C for 1 h, respectively. After washing with cold PBS, infected cells were maintained in the presence or absence of MβCD, either at 4 °C (binding) or 37 °C (internalization), for an additional hour. The virus-infected cells maintained at 37 °C were further treated with proteinase K at 37 °C. The infected cells were then serially diluted and plated onto fresh target cells. At 2 days post-incubation, internalized viruses were titrated by IFA and plaque assay for PRRSV (A) and PEDV (B), respectively. The results are expressed as the mean values from three independent experiments performed in triplicate, and error bars represent standard deviations. *, P = 0.001 to 0.05; **, P < 0.001