High-density lipoproteins reduce the neutralizing effect of hepatitis C virus (HCV)-infected patient antibodies by promoting HCV entry

J Gen Virol. 2006 Sep;87(Pt 9):2577-2581. doi: 10.1099/vir.0.81932-0.

Abstract

The neutralizing activity of anti-hepatitis C virus (HCV) antibodies is attenuated by a factor present in human sera, which has been proposed to be high-density lipoproteins (HDLs). HDLs have also been shown to facilitate the entry of HCV pseudoparticles (HCVpp) into target cells. Here, the aim of the study was to determine whether HDL-mediated facilitation of HCVpp and infectious HCV (HCVcc) entry and attenuation of neutralization are two related phenomena. The data indicated that HDLs attenuate neutralization at a constant rate. In addition, as for HDL-mediated facilitation of HCVpp entry, attenuation of neutralization depended on the expression of the scavenger receptor BI (SR-BI) and its selective lipid-uptake function. Finally, kinetic experiments showed that HDL-mediated facilitation of HCVpp entry is more rapid than virus neutralization. Altogether, these observations indicate that HCV is exploiting the physiological activity of SR-BI for promoting its entry into target cells, which consequently also protects the virus against neutralizing antibodies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Hepacivirus / pathogenicity*
  • Hepacivirus / physiology
  • Hepatitis C / blood
  • Hepatitis C / immunology
  • Hepatitis C / virology
  • Hepatitis C Antibodies / immunology*
  • Humans
  • In Vitro Techniques
  • Lipoproteins, HDL / immunology
  • Lipoproteins, HDL / physiology*
  • Neutralization Tests
  • Scavenger Receptors, Class B / physiology

Substances

  • Antibodies, Monoclonal
  • Hepatitis C Antibodies
  • Lipoproteins, HDL
  • SCARB1 protein, human
  • Scavenger Receptors, Class B