Cellular membrane cholesterol is required for porcine reproductive and respiratory syndrome virus entry and release in MARC-145 cells

Sun, Ying; Xiao, ShaoBo; Wang, Dang; Luo, Rui; Li, Bin; Chen, HuanChun; Fang, LiuRong

If the inhibition of PRRSV replication was specifically due to the cholesterol depletion by MβCD, then cholesterol replenishment in MβCD-treated cells should restore PRRSV replication. To clarify this hypothesis, MβCD-treated cells were incubated with DMEM containing water-soluble cho- lesterol and then cholesterol levels were measured. As shown in Figure 2D , the cellular cholesterol level of MβCD-cholesterol-treated cells was partially restored to 85% of mock-treated cell cholesterol levels. Subsequently, virus yields from the infected MβCD-cholesterol-treated cells were assayed and compared with that from MβCD-treated cells. The titer of PRRSV from the infected MβCD-cholesterol-treated cells was increased to approximately 3.35×10 3 -fold of that from MβCD-treated cells ( Figure 2E ). These results definitively demonstrated that decreasing cellular cholesterol levels resulted in the reduced ability of PRRSV replication and with the replenishment of cellular cholesterol, virus replication was restored to a certain extent.