title: Ceramide enrichment of the plasma membrane induces CD81 internalization and inhibits hepatitis C virus entry.
abstract: Virus entry is a major step in which host-cell lipids can play an essential role. In this report, we investigated the importance of sphingolipids in hepatitis C virus (HCV) entry. For this purpose, sphingomyelin present in the plasma membrane of target cells was hydrolysed into ceramide by sphingomyelinase treatment. Interestingly, ceramide enrichment of the plasma membrane strongly inhibited HCV entry. To understand how ceramide affected HCV entry, we analysed the effect of ceramide enrichment of the plasma membrane on three cell-surface molecules identified as entry factors for HCV: CD81 tetraspanin, scavenger receptor BI and Claudin-1. These proteins, which we found to be mainly associated with detergent-soluble membranes in Huh-7 cells, were not relocated in detergent-resistant microdomains after sphingomyelin hydrolysis into ceramide. Importantly, ceramide enrichment of the plasma membrane led to a 50% decrease in cell-surface CD81, which was due to its ATP-independent internalization. Our results strongly suggest that the ceramide-induced internalization of CD81 is responsible for the inhibitory effect of ceramide on HCV entry. Together, these data indicate that some specific lipids of the plasma membrane are essential for HCV entry and highlight plasma membrane lipids as potential targets to block HCV entry.
authors.affiliation: Institut de Biologie de Lille (UMR8161), CNRS, Université de Lille I and II and Institut Pasteur de Lille, Lille, France.
authors.forename: Cécile
authors.initials: C
authors.lastname: Voisset
authors.forename: Muriel
authors.initials: M
authors.lastname: Lavie
authors.forename: François
authors.initials: F
authors.lastname: Helle
authors.forename: Anne
authors.initials: A
authors.lastname: Op De Beeck
authors.forename: Angéline
authors.initials: A
authors.lastname: Bilheu
authors.forename: Justine
authors.initials: J
authors.lastname: Bertrand-Michel
authors.forename: François
authors.initials: F
authors.lastname: Tercé
authors.forename: Laurence
authors.initials: L
authors.lastname: Cocquerel
authors.forename: Czeslaw
authors.initials: C
authors.lastname: Wychowski
authors.forename: Ngoc
authors.initials: N
authors.lastname: Vu-Dac
authors.forename: Jean
authors.initials: J
authors.lastname: Dubuisson
mesh_terms: D015703:Antigens, CD / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D002518:Ceramides / Q000378:metabolism*; D062445:Claudin-1; D016174:Hepacivirus / Q000502:physiology*; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism; D051122:Scavenger Receptors, Class B / Q000378:metabolism; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D013109:Sphingomyelins / Q000378:metabolism; D060225:Tetraspanin 28; D053586:Virus Internalization
chemical_list: D015703:Antigens, CD; C554798:CD81 protein, human; C568108:CLDN1 protein, human; D002518:Ceramides; D062445:Claudin-1; D008565:Membrane Proteins; C495124:SCARB1 protein, human; D051122:Scavenger Receptors, Class B; D013109:Sphingomyelins; D060225:Tetraspanin 28; D013108:Sphingomyelin Phosphodiesterase