Recombinant human L-ficolin directly neutralizes hepatitis C virus entry

J Innate Immun. 2014;6(5):676-84. doi: 10.1159/000362209. Epub 2014 May 15.

Abstract

L-ficolin is a soluble pattern recognition molecule expressed by the liver that contributes to innate immune defense against microorganisms. It is well described that binding of L-ficolin to specific pathogen-associated molecular patterns activates the lectin complement pathway, resulting in opsonization and lysis of pathogens. In this study, we demonstrated that in addition to this indirect effect, L-ficolin has a direct neutralizing effect against hepatitis C virus (HCV) entry. Specific, dose-dependent binding of recombinant L-ficolin to HCV glycoproteins E1 and E2 was observed. This interaction was inhibited by soluble L-ficolin ligands. Interaction of L-ficolin with E1 and E2 potently inhibited entry of retroviral pseudoparticles bearing these glycoproteins. L-ficolin also inhibited entry of cell-cultured HCV in a calcium-dependent manner. Neutralizing concentrations of L-ficolin were found to be circulating in the serum of HCV-infected individuals. This is the first description of direct neutralization of HCV entry by a ficolin and highlights a novel role for L-ficolin as a virus entry inhibitor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Complement Pathway, Mannose-Binding Lectin
  • Ficolins
  • HEK293 Cells
  • Hepacivirus / pathogenicity
  • Hepacivirus / physiology*
  • Hepatitis C / immunology*
  • Hepatitis C / transmission
  • Humans
  • Lectins / metabolism*
  • Liver / drug effects*
  • Liver / physiology
  • Liver / virology
  • Protein Binding / drug effects
  • Receptors, Pattern Recognition / metabolism*
  • Recombinant Proteins / metabolism*
  • Viral Envelope Proteins / metabolism
  • Virulence
  • Virus Internalization / drug effects

Substances

  • E1 protein, Hepatitis C virus
  • Lectins
  • Receptors, Pattern Recognition
  • Recombinant Proteins
  • Viral Envelope Proteins
  • glycoprotein E2, Hepatitis C virus