Fig. 3.

Porcine nidovirus infection efficiency after cholesterol depletion and replenishment in cellular membranes. PAM-pCD163 and Vero cells were preincubated with various concentrations of MβCD with (+) or without (–) exogenous cholesterol and infected with PRRSV and PEDV, respectively, in the presence or absence of MβCD and/or exogenous cholesterol as indicated. 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 (A) or PEDV (B) by FACS. Virus production in PAM-pCD163 and Vero cells treated with MβCD and cholesterol that was significantly different from that in cells treated with MβCD alone is indicated. The data are presented as the mean values from three independent experiments, and error bars represent standard deviations. *, P = 0.001 to 0.05; **, P < 0.001