title: Impact of intra- and interspecies variation of occludin on its function as coreceptor for authentic hepatitis C virus particles.
abstract: Hepatitis C virus (HCV) is characterized by a narrow host range and high interindividual variability in the clinical course of infection. Both of these traits are thought to be largely due to genetic variation between species and between individual hosts. The tight junction component occludin (OCLN) is essential for HCV entry into host cells, and the differences between human and murine OCLN are thought to account in part for the inability of HCV to infect mice and hence preclude their use as a convenient small-animal model. This study assesses the impact of genetic variation in OCLN on cell culture-grown HCV (HCVcc) using a newly generated and characterized OCLN(low) subclone of the Huh-7.5 cell line (Huh-7.5 subclone in which endogenous OCLN expression has been downregulated by a short hairpin RNA). We report the frequency of coding nonsynonymous single nucleotide polymorphisms, i.e., polymorphisms resulting in amino acid exchanges, present in the human population and determine their ability to function as HCV (co)receptors. Moreover, we show that murine OCLN can sustain HCVcc entry, albeit with about 5-fold reduced efficiency compared to that of human OCLN. This reduction in efficiency is due solely to two amino acid residues previously identified by others using an HCV pseudoparticle approach. Finally, we use the Huh-7.5/OCLN(low) cell line to show that HCV spread between neighboring cells is strictly dependent on OCLN.
authors.affiliation: Medizinische Hochschule Hannover, Klinik für Gastroenterologie, Hepatologie und Endokrinologie, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Ciesek
authors.forename: Sandra
authors.initials: S
authors.lastname: Westhaus
authors.forename: Melanie
authors.initials: M
authors.lastname: Wicht
authors.forename: Ilka
authors.initials: I
authors.lastname: Wappler
authors.forename: Sylvana
authors.initials: S
authors.lastname: Henschen
authors.forename: Christoph
authors.initials: C
authors.lastname: Sarrazin
authors.forename: Nabila
authors.initials: N
authors.lastname: Hamdi
authors.forename: Ahmed I
authors.initials: AI
authors.lastname: Abdelaziz
authors.forename: Christian P
authors.initials: CP
authors.lastname: Strassburg
authors.forename: Heiner
authors.initials: H
authors.lastname: Wedemeyer
authors.forename: Michael P
authors.initials: MP
authors.lastname: Manns
authors.forename: Thomas
authors.initials: T
authors.lastname: Pietschmann
authors.forename: Thomas
authors.initials: T
authors.lastname: von Hahn
mesh_terms: D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002460:Cell Line; D005434:Flow Cytometry; D005787:Gene Frequency; D016174:Hepacivirus / Q000502:physiology*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D051379:Mice; D062793:Occludin; D020641:Polymorphism, Single Nucleotide; D012313:RNA / Q000235:genetics; D011991:Receptors, Virus / Q000502:physiology*; D013045:Species Specificity; D014771:Virion / Q000502:physiology*; D014779:Virus Replication
chemical_list: D008565:Membrane Proteins; C568985:OCLN protein, human; D062793:Occludin; C568986:Ocln protein, mouse; D011991:Receptors, Virus; D012313:RNA