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

Institute for Biomedical Research, University of Birmingham, Birmingham, United Kingdom.
Hepatology (Impact Factor: 11.06). 11/2007; 47(1):17-24. DOI: 10.1002/hep.21959
Source: PubMed


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.

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Available from: Geert Leroux-Roels, Sep 30, 2015
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    • "Further studies have demonstrated that HCV internalization requires the clathrinmediated endocytosis (Blanchard et al., 2006) and that the acidic pH of the early endosomes is essential to trigger fusion and uncoating (Meertens et al., 2006). The virus can also use a neutralizing antibody resistant transfer called cell-cell transmission (Timpe et al., 2008; Witteveldt et al., 2009). "
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    ABSTRACT: Hepatitis C virus (HCV) chronic infection is a major cause of hepatocellular carcinoma. Sorafenib is the only medical treatment that has been approved for the treatment of this cancer. It is a multikinase inhibitor with anti-tumor activity against a wide variety of cancers. Sorafenib blocks angiogenesis and tumor cell proliferation through inhibition of kinases, such as VEGFR2, PDGFR, or the serine/threonine kinases RAF. Previous studies have reported an anti-HCV effect of sorafenib in vitro, but various mechanisms of action have been described. The aim of this study was to clarify the action of sorafenib on the complete HCV infectious cycle. In order to examine the action of sorafenib on all steps of the HCV infectious cycle, we used a combination of validated cell culture models, based on the HuH-7 reference cell line and primary human hepatocytes. We found that sorafenib blocks HCV infection by altering the viral entry step and the production of viral particles. Moreover, we observed that treatment with sorafenib lead to a modification of Claudin-1 expression and localization, which could partly be responsible for the anti-HCV effect. Collectively, our findings confirm the anti-HCV effect of sorafenib in vitro, while highlighting the complexity of the action of sorafenib on the HCV infectious cycle. Copyright © 2015. Published by Elsevier B.V.
    Antiviral research 03/2015; 24. DOI:10.1016/j.antiviral.2015.03.012 · 3.94 Impact Factor
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    • "In addition to cell-free virus infection, HCV has been shown to spread efficiently from one infected cell to a neighboring one [34]. This alternative transmission route is resistant to anti-E2 neutralizing antibodies, thus could be important in vivo. "
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    ABSTRACT: Significant progress has been made in Hepatitis C virus (HCV) culture since the JFH1 strain cloning. However, developing efficient and physiologically relevant culture systems for all viral genotypes remains an important goal. In this work, we aimed at producing a high titer JFH1 derived virus to test different hepatic cells' permissivity. To this end, we performed successive infections and obtained a JFH1 derived virus reaching high titers. Six potential adaptive mutations were identified (I599V in E2, R1373Q and M1611T in NS3, S2364P and C2441S in NS5A and R2523K in NS5B) and the effect of these mutations on HCV replication and infectious particle production was investigated. This cell culture adapted virus enabled us to efficiently infect primary human hepatocytes, as demonstrated using the RFP-NLS-IPS reporter protein and intracellular HCV RNA quantification. However, the induction of a strong type III interferon response in these cells was responsible for HCV inhibition. The disruption of this innate immune response led to a strong infection enhancement and permitted the detection of viral protein expression by western blotting as well as progeny virus production. This cell culture adapted virus also enabled us to easily compare the permissivity of seven hepatoma cell lines. In particular, we demonstrated that HuH-7, HepG2-CD81, PLC/PRF/5 and Hep3B cells were permissive to HCV entry, replication and secretion even if the efficiency was very low in PLC/PRF/5 and Hep3B cells. In contrast, we did not observe any infection of SNU-182, SNU-398 and SNU-449 hepatoma cells. Using iodixanol density gradients, we also demonstrated that the density profiles of HCV particles produced by PLC/PRF/5 and Hep3B cells were different from that of HuH-7 and HepG2-CD81 derived virions. These results will help the development of a physiologically relevant culture system for HCV patient isolates.
    PLoS ONE 08/2013; 8(8):e70809. DOI:10.1371/journal.pone.0070809 · 3.23 Impact Factor
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    • "In addition to cell-free virus entry, where CD81 has been described as an essential factor [12], [14], [15], [16], [17], [30], [31], HCV uses direct cell-cell transfer to infect neighbouring cells and persist in the presence of virus-neutralizing antibodies [10]. This process also seems to require several HCV host factors including CD81, SR-BI, CLDN1, OCLN, EGFR, EphA2 and NPC1L1 [10], [25], [32], [33] but has been less extensively characterized than cell-free entry. Although a CD81-independent route of HCV spread has been described [10], [34], [35], the exact role of CD81 in viral cell-cell transmission remains unknown. "
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    ABSTRACT: Hepatitis C virus (HCV) infection is a challenge to prevent and treat because of the rapid development of drug resistance and escape. Viral entry is required for initiation, spread, and maintenance of infection, making it an attractive target for antiviral strategies. Using genetic immunization, we produced four monoclonal antibodies (mAbs) against the HCV host entry factor CD81. The effects of antibodies on inhibition of HCV infection and dissemination were analyzed in HCV permissive human liver cell lines. The anti-CD81 mAbs efficiently inhibited infection by HCV of different genotypes as well as a HCV escape variant selected during liver transplantation and re-infecting the liver graft. Kinetic studies indicated that anti-CD81 mAbs target a post-binding step during HCV entry. In addition to inhibiting cell-free HCV infection, one antibody was also able to block neutralizing antibody-resistant HCV cell-cell transmission and viral dissemination without displaying any detectable toxicity. A novel anti-CD81 mAb generated by genetic immunization efficiently blocks HCV spread and dissemination. This antibody will be useful to further unravel the role of virus-host interactions during HCV entry and cell-cell transmission. Furthermore, this antibody may be of interest for the development of antivirals for prevention and treatment of HCV infection.
    PLoS ONE 05/2013; 8(5):e64221. DOI:10.1371/journal.pone.0064221 · 3.23 Impact Factor
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