Previous Article | Next Article 
Journal of Virology, August 2009, p. 8012-8020, Vol. 83, No. 16
0022-538X/09/$08.00+0 doi:10.1128/JVI.00038-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
The Tight Junction-Associated Protein Occludin Is Required for a Postbinding Step in Hepatitis C Virus Entry and Infection
Ignacio Benedicto,1,2
Francisca Molina-Jiménez,1,2
Birke Bartosch,3,4,10,11
François-Loïc Cosset,3,10,11
Dimitri Lavillette,3,10,11
Jesús Prieto,2,5,6
Ricardo Moreno-Otero,2,7
Agustín Valenzuela-Fernández,8
Rafael Aldabe,2,6
Manuel López-Cabrera,1,2,9 and
Pedro L. Majano1,2*
Molecular Biology Unit, Hospital Universitario de la Princesa, Madrid, Spain,1 CIBER-ehd, Instituto de Salud Carlos III, Madrid, Spain,2 Université de Lyon, UCB-Lyon1, IFR128, Lyon F-69007, France,3 Hospices Civils de Lyon (HCL), Lyon, France,4 Liver Unit, Clínica Universitaria, Universidad de Navarra, Pamplona, Spain,5 Division of Gene Therapy and Hepatology, Centro de Investigación en Medicina Aplicada, CIMA, Pamplona, Spain,6 Liver Unit, Hospital Universitario de la Princesa, Madrid, Spain,7 Cellular and Viral Immunology Laboratory, Pharmacology Unit, Departamento de Medicina Física y Farmacología, Facultad de Medicina, Instituto de Tecnologías Biomédicas, Universidad de La Laguna, and Instituto Canario de Investigación del Cáncer (ICIC), Tenerife, Spain,8 Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC), Cantoblanco, Madrid, Spain,9 INSERM, U758, Lyon F-69007, France,10 Ecole Normale Supérieure de Lyon, Lyon-F-69007, France,11
Received 8 January 2009/ Accepted 28 May 2009
The precise mechanisms regulating hepatitis C virus (HCV) entry into hepatic cells remain unknown. However, several cell surface proteins have been identified as entry factors for this virus. Of these molecules, claudin-1, a tight junction (TJ) component, is considered a coreceptor required for HCV entry. Recently, we have demonstrated that HCV envelope glycoproteins (HCVgp) promote structural and functional TJ alterations. Additionally, we have shown that the intracellular interaction between viral E2 glycoprotein and occludin, another TJ-associated protein, could be the cause of the mislocalization of TJ proteins. Herein we demonstrated, by using cell culture-derived HCV particles (HCVcc), that interference of occludin expression markedly reduced HCV infection. Furthermore, our results with HCV pseudotyped particles indicated that occludin, but not other TJ-associated proteins, such as junctional adhesion molecule A or zonula occludens protein 1, was required for HCV entry. Using HCVcc, we demonstrated that occludin did not play an essential role in the initial attachment of HCV to target cells. Surface protein labeling experiments showed that both expression levels and cell surface localization of HCV (co)receptors CD81, scavenger receptor class B type I, and claudin-1 were not affected upon occludin knockdown. In addition, immunofluorescence confocal analysis showed that occludin interference did not affect subcellular distribution of the HCV (co)receptors analyzed. However, HCVgp fusion-associated events were altered after occludin silencing. In summary, we propose that occludin plays an essential role in HCV infection and probably affects late entry events. This observation may provide new insights into HCV infection and related pathogenesis.
* Corresponding author. Mailing address: Unidad Biología Molecular, Hospital Universitario de la Princesa, C/ Diego de León 62, 28006 Madrid, Spain. Phone: 34-91-5203462. Fax: 34-91-3093911. E-mail: pmajano.hlpr{at}salud.madrid.org
Published ahead of print on 10 June 2009.
Journal of Virology, August 2009, p. 8012-8020, Vol. 83, No. 16
0022-538X/09/$08.00+0 doi:10.1128/JVI.00038-09
Copyright © 2009, American Society for Microbiology. All Rights Reserved.
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»