Infection by a DAF-using strain of echovirus 11 is dependent upon cholesterol and an intact cytoskeleton, indicating entry via lipid rafts, whereas a non-DAF-using mutant was unaffected.
The glycosylphosphatidylinositol (GPI)-anchored complement regulatory protein decay-accelerating factor (DAF) is used by a number of enteroviruses as a receptor during infection. DAF and other GPI-anchored proteins can be found in cholesterol-rich ordered domains within the plasma membrane that are known as "lipid rafts." We have shown, by using drugs to specifically inhibit various endocytosis routes, that infection by a DAF-using strain of echovirus 11 (EV11) is dependent upon cholesterol and an intact cytoskeleton, whereas a non-DAF-using mutant derived from it was unaffected by these drugs. Using RNA transfection and virus-binding assays, we have shown that this requirement for cholesterol, the actin cytoskeleton, and the microtubule network occurs postbinding of the virus but prior to uncoating of the RNA, indicating a role during virus entry. Confocal microscopy of virus infection supported the role of cholesterol and the cytoskeleton during entry. In addition, (35)Smethionine-labeled DAF-using EV11, but not the non-DAF-using EV11, could be copurified with lipid raft components during infection after Triton X-100 extraction. These data indicate that DAF usage by EV11 enables the virus to associate with lipid rafts and enter cells through this novel route.
Stuart et al. (Sun,) conducted a other in Echovirus 11 infection (in vitro). Endocytosis inhibitors (nystatin, chlorpromazine, nocodazole, cytochalasin D) vs. Untreated cells / non-DAF-using mutant (EV11-207R) was evaluated on Viral infection and entry. Infection by a DAF-using strain of echovirus 11 is dependent upon cholesterol and an intact cytoskeleton, indicating entry via lipid rafts, whereas a non-DAF-using mutant was unaffected.