Apolipoprotein E Interacts With Hepatitis C Virus... : Hepatology (original) (raw)

Viral Hepatitis

Apolipoprotein E Interacts With Hepatitis C Virus Nonstructural Protein 5A and Determines Assembly of Infectious Particles

Benga, Wagane J. A.1,2,†; Krieger, Sophie E.1,2,†; Dimitrova, Maria1,2,†; Zeisel, Mirjam B.1,2; Parnot, Marie1,2; Lupberger, Joachim1,2; Hildt, Eberhard3; Luo, Guangxiang4; McLauchlan, John5; Baumert, Thomas F.1,2,6,**; Schuster, Catherine1,2,*

1_Institut National de la Santé et de la Recherche Médicale (INSERM) Unite 748, Strasbourg, France_

2_Institut de Virologie, Université de Strasbourg, Strasbourg, France_

3_Institut für Infektionsmedizin, Molekulare Medizinische Virologie, Kiel, Germany_

4_Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky College of Medicine, Lexington, KY_

5_MRC Virology Unit, Glasgow, UK_

6_Pôle Hépato-digestif, Nouvel Hôpital Civil, Hôpitaux Universitaires de Strasbourg, Strasbourg, France_

*Address reprint requests to: Inserm U748, 3 rue Koeberlé, F-67000 Strasbourg, France. Email:[email protected]; fax: (33)-3-68-85-37-24.

**Address reprint requests to: Inserm U748, 3 rue Koeberlé, F-67000 Strasbourg, France. Email:[email protected]; fax: (33)-3-68-85-37-50.

Received 5 May 2009; Accepted 30 August 2009

Published online 9 September 2009 in Wiley InterScience (www.interscience.wiley.com).

Supported by Inserm, France, the European Union (LSHM-CT-2004-503359, ERC-2008-AdG-233130-HEPCENT and INTERREG IV “Hepato-Regio-Net”), the Chair of Excellence Program of the Agence Nationale de la Recherche (ANR-05-CEXC-008), France, the Agence Nationale de la Recherche sur le SIDA et les Hépatites Virales (ANRS-06221 and 2008/354), France, the FRM-BNP Paribas Foundation, Paris, France, the CONECTUS programme of the University of Strasbourg, France, and the Else-Kröner-Fresenius Foundation (P17/07//A83/06), Bad Homburg, Germany.

Potential conflict of interest: Nothing to report.

†These authors contributed equally to this work.

Abstract

Chronic hepatitis C virus (HCV) infection is a major cause of liver disease worldwide. Restriction of HCV infection to human hepatocytes suggests that liver-specific host factors play a role in the viral life cycle. Using a yeast-two-hybrid system, we identified apolipoprotein E (apoE) as a liver-derived host factor specifically interacting with HCV nonstructural protein 5A (NS5A) but not with other viral proteins. The relevance of apoE–NS5A interaction for viral infection was confirmed by co-immunoprecipitation and co-localization studies of apoE and NS5A in an infectious HCV cell culture model system. Silencing apoE expression resulted in marked inhibition of infectious particle production without affecting viral entry and replication. Analysis of particle production in liver-derived cells with silenced apoE expression showed impairment of infectious particle assembly and release. The functional relevance of the apoE–NS5A interaction for production of viral particles was supported by loss or decrease of apoE–NS5A binding in assembly-defective viral mutants. Conclusion: These results suggest that recruitment of apoE by NS5A is important for viral assembly and release of infectious viral particles. These findings have important implications for understanding the HCV life cycle and the development of novel antiviral strategies targeting HCV–lipoprotein interaction. (Hepatology 2010)