Hepatitis C virus cell-cell transmission in hepatoma cells... : Hepatology (original) (raw)

Viral Hepatitis

Hepatitis C virus cell-cell transmission in hepatoma cells in the presence of neutralizing antibodies

Timpe, Jennifer M.1; Stamataki, Zania1; Jennings, Adam1; Hu, Ke1; Farquhar, Michelle J.1; Harris, Helen J.1; Schwarz, Anne1; Desombere, Isabelle2; Roels, Geert Leroux2; Balfe, Peter1; McKeating, Jane A.1*

1 Institute for Biomedical Research, University of Birmingham, Birmingham, United Kingdom

2 Center for Vaccinology, Ghent University and Hospital, Ghent, Belgium

*Address reprint requests to: Institute for Biomedical Research, University of Birmingham, Birmingham, B15 2TT, United Kingdom

Email:[email protected]

Received 16 April 2007; Accepted 1 August 2007

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

Grant sponsor: Medical Research Council (United Kingdom); Grant sponsor: Wellcome Trust.

Potential conflict of interest: Nothing to report.

fax: (44) 121 414 3599

Abstract

Hepatitis C virus (HCV) infection of Huh-7.5 hepatoma cells results in focal areas of infection where transmission is potentiated by cell-cell contact. To define route(s) of transmission, HCV was allowed to infect hepatoma cells in the presence or absence of antibodies that neutralize cell-free virus infectivity. Neutralizing antibodies (nAbs) reduced cell-free virus infectivity by >95% and had minimal effect(s) on the frequency of infected cells in the culture. To assess whether cell-cell transfer of viral infectivity occurs, HCV-infected cells were cocultured with fluorescently labeled naïve cells in the presence or absence of nAbs. Enumeration by flow cytometry demonstrated cell-cell transfer of infectivity in the presence or absence of nAbs and immunoglobulins from HCV+ patients. The host cell molecule CD81 and the tight junction protein Claudin 1 (CLDN1) are critical factors defining HCV entry. Soluble CD81 and anti-CD81 abrogated cell-free infection of Huh-7.5 and partially inhibited cell-cell transfer of infection. CD81-negative HepG2 hepatoma cells were resistant to cell-free virus infection but became infected after coculturing with JFH-infected cells in the presence of nAb, confirming that CD81-independent routes of cell-cell transmission exist. Further experiments with 293T and 293T-CLDN1 targets suggested that cell-cell transmission is dependent on CLDN1 expression. Conclusion: These data suggest that HCV can transmit in vitro by at least two routes, cell-free virus infection and direct transfer between cells, with the latter offering a novel route for evading nAbs. (Hepatology 2007.)

Abbreviations: Ab, antibody; CFSE, carboxyfluorescein diacetate succinimidyl ester; CLDN1, Claudin 1; CMFDA, 5-chloromethylfluorescein diacetate; DEN3, dengue virus type-3; DMEM, Dulbecco's modified Eagle's medium; FBS, fetal bovine serum; HCV, hepatitis C virus; HCVcc, cell culture–grown hepatitis C virus; HCVpp, hepatitis C virus pseudotype; HTLV-1, human T cell leukemia virus type I; IU, infectious unit; mAb, monoclonal antibody; MFI, mean fluorescence intensity; MLVpp, murine leukemia virus pseudoparticle; nAb, neutralizing antibody; pi., post infection; sCD81, soluble CD81; SEM, standard error of the mean; SI, specific infectivity.