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Colpitts CC, Tawar RG, Mailly L, Thumann C, Heydmann L, Durand SC, Xiao F, Robinet E, Pessaux P, Zeisel MB, Baumert TF. Humanisation of a claudin-1-specific monoclonal antibody for clinical prevention and cure of HCV infection without escape. Gut 2018; 67:736-745. [PMID: 28360099 PMCID: PMC5868241 DOI: 10.1136/gutjnl-2016-312577] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 11/29/2016] [Accepted: 12/07/2016] [Indexed: 01/08/2023]
Abstract
OBJECTIVE HCV infection is a leading cause of chronic liver disease and a major indication for liver transplantation. Although direct-acting antivirals (DAAs) have much improved the treatment of chronic HCV infection, alternative strategies are needed for patients with treatment failure. As an essential HCV entry factor, the tight junction protein claudin-1 (CLDN1) is a promising antiviral target. However, genotype-dependent escape via CLDN6 and CLDN9 has been described in some cell lines as a possible limitation facing CLDN1-targeted therapies. Here, we evaluated the clinical potential of therapeutic strategies targeting CLDN1. DESIGN We generated a humanised anti-CLDN1 monoclonal antibody (mAb) (H3L3) suitable for clinical development and characterised its anti-HCV activity using cell culture models, a large panel of primary human hepatocytes (PHH) from 12 different donors, and human liver chimeric mice. RESULTS H3L3 pan-genotypically inhibited HCV pseudoparticle entry into PHH, irrespective of donor. Escape was likely precluded by low surface expression of CLDN6 and CLDN9 on PHH. Co-treatment of a panel of PHH with a CLDN6-specific mAb did not enhance the antiviral effect of H3L3, confirming that CLDN6 does not function as an entry factor in PHH from multiple donors. H3L3 also inhibited DAA-resistant strains of HCV and synergised with current DAAs. Finally, H3L3 cured persistent HCV infection in human-liver chimeric uPA-SCID mice in monotherapy. CONCLUSIONS Overall, these findings underscore the clinical potential of CLDN1-targeted therapies and describe the functional characterisation of a humanised anti-CLDN1 antibody suitable for further clinical development to complement existing therapeutic strategies for HCV.
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Affiliation(s)
- Che C Colpitts
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Rajiv G Tawar
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Laurent Mailly
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Christine Thumann
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Laura Heydmann
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Sarah C Durand
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Fei Xiao
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Eric Robinet
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Patrick Pessaux
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
- Institut Hospitalo-Universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Mirjam B Zeisel
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Thomas F Baumert
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
- Institut Hospitalo-Universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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Tawar RG, Heydmann L, Bach C, Schüttrumpf J, Chavan S, King BJ, McClure CP, Ball JK, Pessaux P, Habersetzer F, Bartenschlager R, Zeisel MB, Baumert TF. Broad neutralization of hepatitis C virus-resistant variants by Civacir hepatitis C immunoglobulin. Hepatology 2016; 64:1495-1506. [PMID: 27531416 PMCID: PMC7615276 DOI: 10.1002/hep.28767] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 07/19/2016] [Indexed: 12/15/2022]
Abstract
Hepatitis C virus (HCV)-induced end-stage liver disease is the major indication for liver transplantation (LT). However, reinfection of the liver graft is still common, especially in patients with detectable viral load at the time of LT. Limited data are available on direct-acting antivirals in the transplant setting for prevention of graft infection. The human hepatitis C immunoglobulin (HCIG) Civacir is an investigational drug that is currently being developed in an ongoing phase 3 clinical trial assessing its safety and efficacy at preventing HCV recurrence after liver transplantation (LT) in the United States. Using well-characterized patient-derived HCV variants selected during LT, we studied the molecular mechanism of action of Civacir. Inhibition of HCV infection was studied using infectious HCV models including HCV pseudoparticles (HCVpp) and cell culture-derived HCV (HCVcc) containing patient-derived viral envelope glycoproteins from 22 HCV variants isolated from patients before and after LT. The human hepatitis C immune globulin Civacir is an investigational drug that is currently being developed in an ongoing phase 3 clinical trial assessing safety and efficacy to prevent HCV recurrence after LT in the United States. Using well-characterized patient-derived HCV variants selected during LT, we studied the molecular mechanism of action of Civacir. Inhibition of HCV infection was studied using infectious HCV models including HCV pseudoparticles and cell culture-derived HCV containing patient-derived viral envelope glycoproteins from 22 HCV variants isolated from patients before and after liver transplantation. Additionally, we studied neutralization of different HCV genotypes and of direct-acting antiviral-resistant viruses. Our results indicate that Civacir potently, broadly, and dose-dependently neutralizes all tested patient variants in HCV pseudoparticles and cell culture-derived HCV assays including variants displaying resistance to host neutralizing antibodies and antiviral monoclonal antibodies. The half-maximal inhibitory concentrations were independent of the phenotype of the viral variant, indicating that virus neutralization by Civacir is not affected by viral selection. Furthermore, Civacir is equally active against tested direct-acting antiviral-resistant HCV isolates in cell culture. CONCLUSION Collectively, these results demonstrate broad neutralizing activity of Civacir against resistant viruses, likely due to synergy between anti-HCV antibodies derived from different plasma donors, and support its further clinical development for prevention of liver graft infection. (Hepatology 2016;64:1495-1506).
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Affiliation(s)
- Rajiv G Tawar
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Laura Heydmann
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Charlotte Bach
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | | | | | - Barnabas J King
- School of Life Sciences and the NIHR Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - C Patrick McClure
- School of Life Sciences and the NIHR Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Jonathan K Ball
- School of Life Sciences and the NIHR Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Patrick Pessaux
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
- Institut Hospitalo-universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - François Habersetzer
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
- Institut Hospitalo-universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Ralf Bartenschlager
- Department of Infectious Diseases, Molecular Virology, Heidelberg University, Heidelberg, Germany
- German Center for Infection Research, Heidelberg University, Heidelberg, Germany
| | - Mirjam B Zeisel
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Thomas F Baumert
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France.
- University of Strasbourg, Strasbourg, France.
- Institut Hospitalo-universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
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Raziorrouh B, Sacher K, Tawar RG, Emmerich F, Neumann-Haefelin C, Baumert TF, Thimme R, Boettler T. Virus-Specific CD4+ T Cells Have Functional and Phenotypic Characteristics of Follicular T-Helper Cells in Patients With Acute and Chronic HCV Infections. Gastroenterology 2016; 150:696-706.e3. [PMID: 26584604 DOI: 10.1053/j.gastro.2015.11.005] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 10/08/2015] [Accepted: 11/01/2015] [Indexed: 02/01/2023]
Abstract
BACKGROUND & AIMS Follicular T-helper (Tfh) cells contribute to pathogen-specific antibody responses by providing maturation signals to B cells. In mice with viral infections, virus-specific Tfh cells expand and are required to contain the infection. However, less is known about human virus-specific Tfh cells or their functions during infection. We investigated whether virus-specific CD4+ T cells from patients with hepatitis C virus (HCV) infection had phenotypic or functional features of Tfh cells and contribute to the production of HCV-specific antibodies. METHODS We collected blood samples from patients with acute and chronic HCV infection and healthy individuals (controls). We performed MHC class II tetramer analyses, assays to detect intracellular cytokines in response to HCV exposure, and analyses to quantify HCV-specific antibodies. In addition, we collected liver tissues from patients with chronic HCV infection or nonviral liver disease to analyze markers of Tfh cells. RESULTS HCV-specific CD4+ T cells from patients with acute HCV infection expressed markers of Tfh cells and secreted interleukin 21 in response to HCV exposure. Longitudinal analyses of HCV-specific T-cell responses and antibody responses showed an association between expression of inducible T-cell co-stimulator and induction of virus-specific antibodies in patients with acute HCV infection. Markers of Tfh cells were barely detectable in the peripheral blood samples from patients with chronic HCV infection, but were detected in liver tissues. CONCLUSIONS Virus-specific Tfh cells can be detected in blood samples from patients with acute HCV infection; inducible T-cell co-stimulator expression correlates with production of HCV-specific antibodies. In patients with chronic infection, Tfh cells seem to disappear from the blood but are detectable in the liver.
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Affiliation(s)
- Bijan Raziorrouh
- Department of Medicine II, University Hospital Munich-Grosshadern, Munich, Germany
| | - Kathrin Sacher
- Department of Medicine II, University Hospital Freiburg, Freiburg, Germany
| | - Rajiv G Tawar
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Université de Strasbourg, Strasbourg, France
| | - Florian Emmerich
- University Hospital Freiburg, Institute for Cell and Gene Therapy, Freiburg, Germany
| | | | - Thomas F Baumert
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Université de Strasbourg, Strasbourg, France; Institut Hospitalo-Universitaire, Pôle Hépato-Digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Robert Thimme
- Department of Medicine II, University Hospital Freiburg, Freiburg, Germany
| | - Tobias Boettler
- Department of Medicine II, University Hospital Freiburg, Freiburg, Germany.
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4
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Tawar RG, Colpitts CC, Timm J, Fehm T, Roggendorf M, Meisel H, Meyer N, Habersetzer F, Cosset FL, Berg T, Zeisel MB, Baumert TF. Acute hepatitis C virus infection induces anti-host cell receptor antibodies with virus-neutralizing properties. Hepatology 2015; 62:726-36. [PMID: 26010076 DOI: 10.1002/hep.27906] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 05/19/2015] [Indexed: 12/17/2022]
Abstract
UNLABELLED Hepatitis C virus (HCV) causes persistent infection in the majority of infected individuals. The mechanisms of persistence and clearance are only partially understood. Antibodies (Abs) against host cell entry receptors have been shown to inhibit HCV infection in cell culture and animal models. In this study, we aimed to investigate whether anti-receptor Abs are induced during infection in humans in vivo and whether their presence is associated with outcome of infection. We established an enzyme-linked immunosorbant assay using a recombinant CD81-claudin-1 (CLDN1) fusion protein to detect and quantify Abs directed against extracellular epitopes of the HCV CD81-CLDN1 coreceptor complex. The presence of anti-receptor Abs was studied in serum of patients from a well-defined cohort of a single-source HCV outbreak of pregnant women and several control groups, including uninfected pregnant women, patients with chronic hepatitis B and D virus (HBV/HDV) infection, and healthy individuals. Virus-neutralizing activity of Abs was determined using recombinant cell culture-derived HCV (HCVcc). Our results demonstrate that HCV-infected patients have statistically significantly higher anti-CD81/CLDN1 Ab titers during the early phase of infection than controls. The titers were significantly higher in resolvers compared to persisters. Functional studies using immunoadsorption and HCV cell culture models demonstrate that HCV-neutralizing anti-receptor Abs are induced in the early phase of HCV infection, but not in control groups. CONCLUSION The virus-neutralizing properties of these Abs suggest a role for control of viral infection in conjunction with antiviral responses. Characterization of these anti-receptor Abs opens new avenues to prevent and treat HCV infection.
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Affiliation(s)
- Rajiv G Tawar
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France.,University of Strasbourg, Strasbourg, France
| | - Che C Colpitts
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France.,University of Strasbourg, Strasbourg, France
| | - Jörg Timm
- Institute for Virology, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | - Tanja Fehm
- Department of Gynecology and Obstetrics, University Hospital Düsseldorf, Heinrich-Heine-University, Düsseldorf, Germany
| | | | - Helga Meisel
- Institute of Medical Virology, Helmut-Ruska-Haus, Charité University Medicine, Berlin, Germany
| | - Nicolas Meyer
- Pôle de Santé Publique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - François Habersetzer
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France.,University of Strasbourg, Strasbourg, France.,Institut Hospitalo-Universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - François-Loïc Cosset
- CIRI-International Center for Infectiology Research, Lyon, France; Inserm, U1111, Lyon France; Ecole Normale Supérieure; CNRS UMR 5308, Lyon, France; LabEx Ecofect, University of Lyon, Lyon, France
| | - Thomas Berg
- Department of Internal Medicine, Neurology and Dermatology, Gastroenterology and Rheumatology Clinic, Section of Hepatology, University of Leipzig, Leipzig, Germany
| | - Mirjam B Zeisel
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France.,University of Strasbourg, Strasbourg, France
| | - Thomas F Baumert
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France.,University of Strasbourg, Strasbourg, France.,Institut Hospitalo-Universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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5
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Tawar RG, Colpitts CC, Lupberger J, El-Saghire H, Zeisel MB, Baumert TF. Claudins and pathogenesis of viral infection. Semin Cell Dev Biol 2015; 42:39-46. [PMID: 25960372 DOI: 10.1016/j.semcdb.2015.04.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 04/29/2015] [Accepted: 04/29/2015] [Indexed: 01/06/2023]
Abstract
Since their discovery, tremendous progress has been made in our understanding of the roles of claudins in tight junction physiology. In addition, interactions between claudins and other cellular proteins have highlighted their novel roles in cell physiology. Moreover, the importance of claudins is becoming apparent in the pathophysiology of several diseases, including viral infections. Notable is the discovery of CLDN1 as an essential host factor for hepatitis C virus (HCV) entry, which led to detailed characterization of CLDN1 and its association with tetraspanin CD81 for the initiation of HCV infection. CLDN1 has also been shown to facilitate dengue virus entry. Furthermore, owing to the roles of claudins in forming anatomical barriers, several viruses have been shown to alter claudin expression at the tight junction. This review summarizes the role of claudins in viral infection, with particular emphasis on HCV.
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Affiliation(s)
- Rajiv G Tawar
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France; University of Strasbourg, Strasbourg, France
| | - Che C Colpitts
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France; University of Strasbourg, Strasbourg, France
| | - Joachim Lupberger
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France; University of Strasbourg, Strasbourg, France
| | - Hussein El-Saghire
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France; University of Strasbourg, Strasbourg, France
| | - Mirjam B Zeisel
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France; University of Strasbourg, Strasbourg, France
| | - Thomas F Baumert
- Inserm, U1110, Institut des Maladies Virales et Hépatiques, Strasbourg, France; University of Strasbourg, Strasbourg, France; Institut Hospitalo-Universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
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6
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Abstract
The investigation of virus-induced liver disease and hepatocellular carcinoma needs small animal models modeling hepatitis C virus (HCV) infection and liver disease biology. A recent study published in Cell Research reports a novel mouse model which is permissive for chronic HCV infection and shows chronic liver injury including inflammation, steatosis and fibrosis.
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Affiliation(s)
- Rajiv G Tawar
- Inserm, U1110, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
| | - Laurent Mailly
- Inserm, U1110, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
| | - Thomas F Baumert
- Inserm, U1110, Strasbourg, France
- Université de Strasbourg, Strasbourg, France
- Pôle Hépato-digestif, Institut Hospitalo-Universitaire, Strasbourg, France
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7
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Zona L, Lupberger J, Sidahmed-Adrar N, Thumann C, Harris HJ, Barnes A, Florentin J, Tawar RG, Xiao F, Turek M, Durand SC, Duong FHT, Heim MH, Cosset FL, Hirsch I, Samuel D, Brino L, Zeisel MB, Le Naour F, McKeating JA, Baumert TF. HRas signal transduction promotes hepatitis C virus cell entry by triggering assembly of the host tetraspanin receptor complex. Cell Host Microbe 2013; 13:302-13. [PMID: 23498955 DOI: 10.1016/j.chom.2013.02.006] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Revised: 01/03/2013] [Accepted: 02/11/2013] [Indexed: 02/07/2023]
Abstract
Hepatitis C virus (HCV) entry is dependent on coreceptor complex formation between the tetraspanin superfamily member CD81 and the tight junction protein claudin-1 (CLDN1) on the host cell membrane. The receptor tyrosine kinase EGFR acts as a cofactor for HCV entry by promoting CD81-CLDN1 complex formation via unknown mechanisms. We identify the GTPase HRas, activated downstream of EGFR signaling, as a key host signal transducer for EGFR-mediated HCV entry. Proteomic analysis revealed that HRas associates with tetraspanin CD81, CLDN1, and the previously unrecognized HCV entry cofactors integrin β1 and Ras-related protein Rap2B in hepatocyte membranes. HRas signaling is required for lateral membrane diffusion of CD81, which enables tetraspanin receptor complex assembly. HRas was also found to be relevant for entry of other viruses, including influenza. Our data demonstrate that viruses exploit HRas signaling for cellular entry by compartmentalization of entry factors and receptor trafficking.
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Affiliation(s)
- Laetitia Zona
- Inserm, U1110, Institut de Virologie, 67000 Strasbourg, France
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8
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Fofana I, Xiao F, Thumann C, Turek M, Zona L, Tawar RG, Grunert F, Thompson J, Zeisel MB, Baumert TF. A novel monoclonal anti-CD81 antibody produced by genetic immunization efficiently inhibits Hepatitis C virus cell-cell transmission. PLoS One 2013; 8:e64221. [PMID: 23704981 PMCID: PMC3660333 DOI: 10.1371/journal.pone.0064221] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 04/12/2013] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND AND AIMS 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. METHODS 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. RESULTS 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. CONCLUSION 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.
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Affiliation(s)
- Isabel Fofana
- Inserm, U1110, Institute of Virology, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Fei Xiao
- Inserm, U1110, Institute of Virology, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Christine Thumann
- Inserm, U1110, Institute of Virology, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Marine Turek
- Inserm, U1110, Institute of Virology, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Laetitia Zona
- Inserm, U1110, Institute of Virology, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Rajiv G. Tawar
- Inserm, U1110, Institute of Virology, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | | | | | - Mirjam B. Zeisel
- Inserm, U1110, Institute of Virology, Strasbourg, France
- University of Strasbourg, Strasbourg, France
| | - Thomas F. Baumert
- Inserm, U1110, Institute of Virology, Strasbourg, France
- University of Strasbourg, Strasbourg, France
- Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- * E-mail:
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9
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Tawar RG, Duquerroy S, Vonrhein C, Varela PF, Damier-Piolle L, Castagné N, MacLellan K, Bedouelle H, Bricogne G, Bhella D, Eléouët JF, Rey FA. Crystal structure of a nucleocapsid-like nucleoprotein-RNA complex of respiratory syncytial virus. Science 2009; 326:1279-83. [PMID: 19965480 DOI: 10.1126/science.1177634] [Citation(s) in RCA: 248] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The respiratory syncytial virus (RSV) is an important human pathogen, yet neither a vaccine nor effective therapies are available to treat infection. To help elucidate the replication mechanism of this RNA virus, we determined the three-dimensional (3D) crystal structure at 3.3 A resolution of a decameric, annular ribonucleoprotein complex of the RSV nucleoprotein (N) bound to RNA. This complex mimics one turn of the viral helical nucleocapsid complex, which serves as template for viral RNA synthesis. The RNA wraps around the protein ring, with seven nucleotides contacting each N subunit, alternating rows of four and three stacked bases that are exposed and buried within a protein groove, respectively. Combined with electron microscopy data, this structure provides a detailed model for the RSV nucleocapsid, in which the bases are accessible for readout by the viral polymerase. Furthermore, the nucleoprotein structure highlights possible key sites for drug targeting.
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Affiliation(s)
- Rajiv G Tawar
- Institut Pasteur, Unité de Virologie Structurale, Département de Virologie and CNRS Unité de Recherche Associée (URA) 3015, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
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