Hepatitis C virus induces CD81 and claudin-1 endocytosis

J Virol. 2012 Apr;86(8):4305-16. doi: 10.1128/JVI.06996-11. Epub 2012 Feb 8.

Abstract

Hepatitis C virus (HCV) leads to progressive liver disease and hepatocellular carcinoma. Current treatments are only partially effective, and new therapies targeting viral and host pathways are required. Virus entry into a host cell provides a conserved target for therapeutic intervention. Tetraspanin CD81, scavenger receptor class B member I, and the tight-junction proteins claudin-1 and occludin have been identified as essential entry receptors. Limited information is available on the role of receptor trafficking in HCV entry. We demonstrate here that anti-CD81 antibodies inhibit HCV infection at late times after virus internalization, suggesting a role for intracellular CD81 in HCV infection. Several tetraspanins have been reported to internalize via motifs in their C-terminal cytoplasmic domains; however, CD81 lacks such motifs, leading several laboratories to suggest a limited role for CD81 endocytosis in HCV entry. We demonstrate CD81 internalization via a clathrin- and dynamin-dependent process, independent of its cytoplasmic domain, suggesting a role for associated partner proteins in regulating CD81 trafficking. Live cell imaging demonstrates CD81 and claudin-1 coendocytosis and fusion with Rab5 expressing endosomes, supporting a role for this receptor complex in HCV internalization. Receptor-specific antibodies and HCV particles increase CD81 and claudin-1 endocytosis, supporting a model wherein HCV stimulates receptor trafficking to promote particle internalization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / metabolism
  • Antibodies, Neutralizing / immunology
  • Antibodies, Neutralizing / metabolism
  • Antibody Affinity / immunology
  • Cell Line
  • Claudin-1
  • Endocytosis*
  • Hepacivirus / metabolism*
  • Humans
  • Membrane Proteins / metabolism*
  • Protein Structure, Tertiary
  • Protein Transport
  • Receptors, Virus / metabolism
  • Tetraspanin 28 / chemistry
  • Tetraspanin 28 / immunology
  • Tetraspanin 28 / metabolism*
  • Viral Envelope Proteins / metabolism
  • Virus Internalization

Substances

  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • CLDN1 protein, human
  • Claudin-1
  • Membrane Proteins
  • Receptors, Virus
  • Tetraspanin 28
  • Viral Envelope Proteins