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

Being an essential component of cell membrane, cholesterol could potentially inhibit virus entry by several different mechanisms. First, cholesterol may affect virus entry by modifying the interaction of the virus particle with host cell membrane. Cholesterol level is important for maintaining biological membrane fluidity [36] , and its removal could reduce lateral diffusion within the membrane. This reduction in fluidity could probably influence entry of PRRSV within the membrane. Second, the lipid environment, including cholesterol level, is known to affect the charge properties of some ion channels [37] , and the ion channels formed on cellular membrane require the presence of cholesterol for effective cytoplasmic delivery of the viral genome during virus entry. Cholesterol and sphingolipids are components of lipid rafts, and lipid recognition by certain proteins of viruses might be imperative for virus entry [38] . Moreover, there are also other studies indicating that cholesterol removal resulted in an inhibition of cellular signaling pathways [39] .