A novel cell entry pathway for a DAF-using human enterovirus is dependent on lipid rafts.
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)S]methionine-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.
Division of Virology, Department of Pathology, University of Cambridge, CB2 1QP Cambridge, United Kingdom. ads35@mole.bio.cam.ac.uk
Amanda D
AD
Stuart
Hannah E
HE
Eustace
Thomas A
TA
McKee
T D K
TD
Brown
D018958:CD55 Antigens / Q000378:metabolism*; D051242:Caveolin 1; D022461:Caveolins / Q000378:metabolism*; D002460:Cell Line; D002746:Chlorpromazine / Q000494:pharmacology; D002784:Cholesterol / Q000378:metabolism; D015638:Cytochalasin D / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D029822:Enterovirus B, Human / Q000187:drug effects / Q000472:pathogenicity*; D004769:Enterovirus Infections / Q000821:virology; D006801:Humans; D021962:Membrane Microdomains / Q000378:metabolism*; D015739:Nocodazole / Q000494:pharmacology; D009761:Nystatin / Q000494:pharmacology
D018958:CD55 Antigens; D051242:Caveolin 1; D022461:Caveolins; D009761:Nystatin; D015638:Cytochalasin D; D002784:Cholesterol; D015739:Nocodazole; D002746:Chlorpromazine