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Prentoe J, Janitzek CM, Velázquez-Moctezuma R, Soerensen A, Jørgensen T, Clemmensen S, Soroka V, Thrane S, Theander T, Nielsen MA, Salanti A, Bukh J, Sander AF. Two-component vaccine consisting of virus-like particles displaying hepatitis C virus envelope protein 2 oligomers. NPJ Vaccines 2022; 7:148. [DOI: 10.1038/s41541-022-00570-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022] Open
Abstract
AbstractDevelopment of B-cell-based hepatitis C virus (HCV) vaccines that induce broadly neutralizing antibodies (bNAbs) is hindered by extensive sequence diversity and low immunogenicity of envelope glycoprotein vaccine candidates, most notably soluble E2 (sE2). To overcome this, we employed two-component approaches using self-assembling virus-like particles (cVLPs; component 1), displaying monomeric or oligomeric forms of HCV sE2 (sE2mono or sE2oligo; component 2). Immunization studies were performed in BALB/c mice and the neutralizing capacity of vaccine-induced antibodies was tested in cultured-virus-neutralizations, using HCV of genotypes 1–6. sE2-cVLP vaccines induced significantly higher levels of NAbs (p = 0.0065) compared to corresponding sE2 vaccines. Additionally, sE2oligo-cVLP was superior to sE2mono-cVLP in inducing bNAbs. Interestingly, human monoclonal antibody AR2A had reduced binding in ELISA to sE2oligo-cVLP compared with sE2mono-cVLP and competition ELISA using mouse sera from vaccinated animals indicated that sE2oligo-cVLP induced significantly less non-bNAbs AR2A (p = 0.0043) and AR1B (p = 0.017). Thus, cVLP-displayed oligomeric sE2 shows promise as an HCV vaccine candidate.
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Identification of the retinoschisin-binding site on the retinal Na/K-ATPase. PLoS One 2019; 14:e0216320. [PMID: 31048931 PMCID: PMC6497308 DOI: 10.1371/journal.pone.0216320] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 04/19/2019] [Indexed: 01/11/2023] Open
Abstract
X-linked juvenile retinoschisis (XLRS) is a hereditary retinal dystrophy, caused by mutations in the RS1 gene which encodes the secreted protein retinoschisin. In recent years, several molecules have been proposed to interact with retinoschisin, including the retinal Na/K-ATPase, L-voltage gated Ca2+ channels, and specific sugars. We recently showed that the retinal Na/K-ATPase consisting of subunits ATP1A3 and ATP1B2 is essential for anchoring retinoschisin to plasma membranes and identified the glycosylated ATP1B2 subunit as the direct interaction partner for retinoschisin. We now aimed to precisely map the retinoschisin binding domain(s) in ATP1B2. In general, retinoschisin binding was not affected after selective elimination of individual glycosylation sites via site-directed mutagenesis as well as after full enzymatic deglycosylation of ATP1B2. Applying the interface prediction tool PresCont, two putative protein-protein interaction patches (“patch I” and “patch II”) consisting each of four hydrophobic amino acid stretches on the ATP1B2 surface were identified. These were consecutively altered by site-directed mutagenesis. Functional assays with the ATP1B2 patch mutants identified patch II and, specifically, the associated amino acid at position 240 (harboring a threonine in ATP1B2) as crucial for retinoschisin binding to ATP1B2. These and previous results led us to suggest an induced-fit binding mechanism for the interaction between retinoschisin and the Na/K-ATPase, which is dependent on threonine 240 in ATP1B2 allowing the accommodation of hyperflexible retinoschisin spikes by the associated protein-protein interaction patch on ATP1B2.
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Prentoe J, Bukh J. Hypervariable Region 1 in Envelope Protein 2 of Hepatitis C Virus: A Linchpin in Neutralizing Antibody Evasion and Viral Entry. Front Immunol 2018; 9:2146. [PMID: 30319614 PMCID: PMC6170631 DOI: 10.3389/fimmu.2018.02146] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 08/30/2018] [Indexed: 12/15/2022] Open
Abstract
Chronic hepatitis C virus (HCV) infection is the cause of about 400,000 annual liver disease-related deaths. The global spread of this important human pathogen can potentially be prevented through the development of a vaccine, but this challenge has proven difficult, and much remains unknown about the multitude of mechanisms by which this heterogeneous RNA virus evades inactivation by neutralizing antibodies (NAbs). The N-terminal motif of envelope protein 2 (E2), termed hypervariable region 1 (HVR1), changes rapidly in immunoglobulin-competent patients due to antibody-driven antigenic drift. HVR1 contains NAb epitopes and is directly involved in protecting diverse antibody-specific epitopes on E1, E2, and E1/E2 through incompletely understood mechanisms. The ability of HVR1 to protect HCV from NAbs appears linked with modulation of HCV entry co-receptor interactions. Thus, removal of HVR1 increases interaction with CD81, while altering interaction with scavenger receptor class B, type I (SR-BI) in a complex fashion, and decreasing interaction with low-density lipoprotein receptor. Despite intensive efforts this modulation of receptor interactions by HVR1 remains incompletely understood. SR-BI has received the most attention and it appears that HVR1 is involved in a multimodal HCV/SR-BI interaction involving high-density-lipoprotein associated ApoCI, which may prime the virus for later entry events by exposing conserved NAb epitopes, like those in the CD81 binding site. To fully elucidate the multifunctional role of HVR1 in HCV entry and NAb evasion, improved E1/E2 models and comparative studies with other NAb evasion strategies are needed. Derived knowledge may be instrumental in the development of a prophylactic HCV vaccine.
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Affiliation(s)
- Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, Copenhagen, Denmark.,Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, Copenhagen, Denmark.,Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Chang CC, Hsu HJ, Yen JH, Lo SY, Liou JW. A Sequence in the loop domain of hepatitis C virus E2 protein identified in silico as crucial for the selective binding to human CD81. PLoS One 2017; 12:e0177383. [PMID: 28481946 PMCID: PMC5421814 DOI: 10.1371/journal.pone.0177383] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 04/26/2017] [Indexed: 12/15/2022] Open
Abstract
Hepatitis C virus (HCV) is a species-specific pathogenic virus that infects only humans and chimpanzees. Previous studies have indicated that interactions between the HCV E2 protein and CD81 on host cells are required for HCV infection. To determine the crucial factors for species-specific interactions at the molecular level, this study employed in silico molecular docking involving molecular dynamic simulations of the binding of HCV E2 onto human and rat CD81s. In vitro experiments including surface plasmon resonance measurements and cellular binding assays were applied for simple validations of the in silico results. The in silico studies identified two binding regions on the HCV E2 loop domain, namely E2-site1 and E2-site2, as being crucial for the interactions with CD81s, with the E2-site2 as the determinant factor for human-specific binding. Free energy calculations indicated that the E2/CD81 binding process might follow a two-step model involving (i) the electrostatic interaction-driven initial binding of human-specific E2-site2, followed by (ii) changes in the E2 orientation to facilitate the hydrophobic and van der Waals interaction-driven binding of E2-site1. The sequence of the human-specific, stronger-binding E2-site2 could serve as a candidate template for the future development of HCV-inhibiting peptide drugs.
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Affiliation(s)
- Chun-Chun Chang
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.,Department of Laboratory Medicine, Tzu Chi Medical Center, Hualien, Taiwan
| | - Hao-Jen Hsu
- Department of Life Sciences, Tzu Chi University, Hualien, Taiwan
| | - Jui-Hung Yen
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
| | - Shih-Yen Lo
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien, Taiwan
| | - Je-Wen Liou
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.,Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, Taiwan
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Prentoe J, Velázquez-Moctezuma R, Foung SKH, Law M, Bukh J. Hypervariable region 1 shielding of hepatitis C virus is a main contributor to genotypic differences in neutralization sensitivity. Hepatology 2016; 64:1881-1892. [PMID: 27351277 PMCID: PMC5115964 DOI: 10.1002/hep.28705] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 06/15/2016] [Indexed: 12/11/2022]
Abstract
UNLABELLED There are 3-4 million new hepatitis C virus (HCV) infections yearly. The extensive intergenotypic sequence diversity of envelope proteins E1 and E2 of HCV and shielding of important epitopes by hypervariable region 1 (HVR1) of E2 are believed to be major hindrances to developing universally protective HCV vaccines. Using cultured viruses expressing the E1/E2 complex of isolates H77 (genotype 1a), J6 (2a), or S52 (3a), with and without HVR1, we tested HVR1-mediated neutralization occlusion in vitro against a panel of 12 well-characterized human monoclonal antibodies (HMAbs) targeting diverse E1, E2, and E1/E2 epitopes. Surprisingly, HVR1-mediated protection was greatest for S52, followed by J6 and then H77. HCV pulldown experiments showed that this phenomenon was caused by epitope shielding. Moreover, by regression analysis of HMAb binding and neutralization titer of HCV we found a strong correlation for HVR1-deleted viruses but not for parental viruses retaining HVR1. The intergenotype neutralization sensitivity of the parental viruses to HMAb antigenic region (AR) 2A, AR3A, AR4A, AR5A, HC84.26, and HC33.4 varied greatly (>24-fold to >130-fold differences in 50% inhibitory concentration values). However, except for AR5A, these differences decreased to less than 6.0-fold when comparing the corresponding HVR1-deleted viruses. Importantly, this simplified pattern of neutralization sensitivity in the absence of HVR1 was also demonstrated in a panel of HVR1-deleted viruses of genotypes 1a, 2a, 2b, 3a, 5a, and 6a, although for all HMAbs, except AR4A, an outlier was observed. Finally, unique amino acid residues in HCV E2 could explain these outliers in the tested cases of AR5A and HC84.26. CONCLUSION HVR1 adds complexity to HCV neutralization by shielding a diverse array of unexpectedly cross-genotype-conserved E1/E2 epitopes. Thus, an HVR1-deleted antigen could be a better HCV vaccine immunogen. (Hepatology 2016;64:1881-1892).
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Affiliation(s)
- Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark,Corresponding authors Dr. Jannick Prentoe, Ph.D. and Prof. Jens Bukh, M.D., Department of Infectious Diseases #144, Copenhagen University Hospital, Kettegaard Allé 30, DK-2650 Hvidovre, Denmark. ;
| | - Rodrigo Velázquez-Moctezuma
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Steven K. H. Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Mansun Law
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark,Corresponding authors Dr. Jannick Prentoe, Ph.D. and Prof. Jens Bukh, M.D., Department of Infectious Diseases #144, Copenhagen University Hospital, Kettegaard Allé 30, DK-2650 Hvidovre, Denmark. ;
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Studies on the role of neutralizing antibodies against envelope genes in resolving HCV pseudo-particles infection. Mol Biol Rep 2014; 41:3945-50. [PMID: 24566682 DOI: 10.1007/s11033-014-3262-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 02/11/2014] [Indexed: 10/25/2022]
Abstract
Characterization of antibodies targeting the attachment and entry of the viral particles into host cells is important for studding antibody mediated neutralization. Antibodies against the envelope glycoproteins (EGP) have neutralizing capacity and can prevent HCV infections. System based on HCV pseudo typed-particles (HCVpp) stably expressing EGP can be used for screening of HCV anti envelope neutralizing antibodies in the serum of patients with acute and chronic HCV infections. The aim of the current study was to check HCVpp as a useful tool for the detection of anti-HCV envelope antibodies in the serum of HCV infected patients and to test the binding potential of these antiviral molecules to EGP of HCV 3a. Previously developed HCVpp harboring unmodified glycoproteins from local isolates in 293T cell line were used in this study. HCVpp were pre incubated with different concentrations of anti E1 antibody and different E2 antibodies to check antiviral activity. Further we used serum samples with low/medium (≤800,000 IU/mL), and high (>800,000 IU/mL) viral titer from chronic HCV male and female patients. Infection was done in Huh-7 cells for 1 h at 37 oC. Infectivity was checked through Luciferase assay. Considerable decrease in HCVpp infectivity with anti-envelope antibodies was observed in dose dependent manner. Maximum inhibition was seen when 5 µg/ml of monoclonal anti E1 antibody used. Further increase in concentration exhibited no decrease in infectivity which suggests that other factors are also involved in causing infection. Various well characterized E2-specific monoclonal antibodies (mAbs) have been screened for their capability to reduce infection in Huh-7 cells. Three of the four mAbs specific for the E2 had no effect on the infectivity of HCVpp. Confirmation sensitive antibody H53 showed maximum inhibition of infectivity. HCV ELISA positive samples from both male and female patients were used to neutralize the HCVpp. The neutralizing antibody response was observed in both males and females patients and do not assemble the rapidly evolving HCV envelope glycoproteins. That is why in spite the presence of neutralizing antibodies in the blood they fail to resolve infections. Moreover E1 antibodies insignificantly (>0.05) inhibit HCVpp infectivity while E2 antibodies significantly (<0.05) inhibit HCVpp infection. Based on the results of this study it is concluded that anti-envelope antibodies particularly the anti-E2 could be extremely valuable for characterizing the humoral immune response to HCV and for evaluating the potential for developing passive and active immunization for hepatitis C along with interferon therapy.
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Fénéant L, Levy S, Cocquerel L. CD81 and hepatitis C virus (HCV) infection. Viruses 2014; 6:535-72. [PMID: 24509809 PMCID: PMC3939471 DOI: 10.3390/v6020535] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Revised: 01/29/2014] [Accepted: 02/02/2014] [Indexed: 12/16/2022] Open
Abstract
Hepatitis C Virus (HCV) infection is a global public health problem affecting over 160 million individuals worldwide. Its symptoms include chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped RNA virus mainly targeting liver cells and for which the initiation of infection occurs through a complex multistep process involving a series of specific cellular entry factors. This process is likely mediated through the formation of a tightly orchestrated complex of HCV entry factors at the plasma membrane. Among HCV entry factors, the tetraspanin CD81 is one of the best characterized and it is undoubtedly a key player in the HCV lifecycle. In this review, we detail the current knowledge on the involvement of CD81 in the HCV lifecycle, as well as in the immune response to HCV infection.
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Affiliation(s)
- Lucie Fénéant
- Center for Infection and Immunity of Lille, CNRS-UMR8204, Inserm-U1019, Institut Pasteur de Lille, Université Lille Nord de France, Institut de Biologie de Lille, 1 rue du Pr Calmette, CS50447, 59021 Lille Cedex, France.
| | - Shoshana Levy
- Department of Medicine, Division of Oncology, CCSR, Stanford University Medical Center, Stanford, CA 94305, USA.
| | - Laurence Cocquerel
- Center for Infection and Immunity of Lille, CNRS-UMR8204, Inserm-U1019, Institut Pasteur de Lille, Université Lille Nord de France, Institut de Biologie de Lille, 1 rue du Pr Calmette, CS50447, 59021 Lille Cedex, France.
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Shimizu YK, Hijikata M, Oshima M, Shimizu K, Alter HJ, Purcell RH, Yoshikura H, Hotta H. Isolation of human monoclonal antibodies to the envelope e2 protein of hepatitis C virus and their characterization. PLoS One 2013; 8:e55874. [PMID: 23409074 PMCID: PMC3567033 DOI: 10.1371/journal.pone.0055874] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 01/03/2013] [Indexed: 11/18/2022] Open
Abstract
We isolated and characterized two human monoclonal antibodies to the envelope E2 protein of hepatitis C virus (HCV). Lymphoblastoid cell lines stably producing antibodies were obtained by immortalizing peripheral blood mononuclear cells of a patient with chronic hepatitis C using Epstein-Barr virus. Screening for antibody-positive clones was carried out by immunofluorescence with Huh7 cells expressing the E2 protein of HCV strain H (genotype 1a) isolated from the same patient. Isotype of resulting antibodies, #37 and #55, was IgG1/kappa and IgG1/lambda, respectively. Epitope mapping revealed that #37 and #55 recognize conformational epitopes spanning amino acids 429 to 652 and 508 to 607, respectively. By immunofluorescence using virus-infected Huh7.5 cells as targets both antibodies were reactive with all of the nine different HCV genotypes/subtypes tested. The antibodies showed a different pattern of immuno-staining; while #37 gave granular reactions mostly located in the periphery of the nucleus, #55 gave diffuse staining throughout the cytoplasm. Both antibodies were shown by immuno-gold electron microscopy to bind to intact viral particles. In a neutralization assay (focus-forming unit reduction using chimeric infectious HCV containing structural proteins derived from genotypes 1a, 1b, 2a, 2b, 3a, 4a, 5a, 6a, and 7a), #55 inhibited the infection of all HCV genotypes tested but genotype 7a to a lesser extent. #37 did not neutralize any of these viruses. As a broadly cross-neutralizing human antibody, #55 may be useful for passive immunotherapy of HCV infection.
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MESH Headings
- Amino Acid Sequence
- Antibodies, Blocking/immunology
- Antibodies, Blocking/metabolism
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/immunology
- Antibodies, Neutralizing
- Antibodies, Viral/chemistry
- Antibodies, Viral/genetics
- Antibodies, Viral/immunology
- Antibody Affinity/immunology
- Antigens, Viral/chemistry
- Antigens, Viral/immunology
- Antigens, Viral/metabolism
- Cell Line, Transformed
- Cross Reactions/immunology
- Epitope Mapping
- Epitopes/chemistry
- Epitopes/immunology
- Genotype
- Hepacivirus/genetics
- Hepacivirus/immunology
- Humans
- Immunoglobulin G/chemistry
- Immunoglobulin G/genetics
- Immunoglobulin G/immunology
- Immunoglobulin Heavy Chains/chemistry
- Immunoglobulin Heavy Chains/genetics
- Lymphocytes/immunology
- Lymphocytes/metabolism
- Molecular Sequence Data
- Neutralization Tests
- Protein Transport
- Sequence Alignment
- Viral Envelope Proteins/immunology
- Viral Envelope Proteins/metabolism
- Virion/immunology
- Virion/ultrastructure
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Affiliation(s)
- Yohko K Shimizu
- Division of Microbiology, Center for Infectious Diseases, Kobe University Graduate School of Medicine, Kobe, Japan.
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Vieyres G, Dubuisson J, Patel AH. Characterization of antibody-mediated neutralization directed against the hypervariable region 1 of hepatitis C virus E2 glycoprotein. J Gen Virol 2011; 92:494-506. [PMID: 21084495 PMCID: PMC3081231 DOI: 10.1099/vir.0.028092-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2010] [Accepted: 11/17/2010] [Indexed: 12/15/2022] Open
Abstract
The hypervariable region 1 (HVR1) comprising the first 27 aa of E2 glycoprotein is a target for neutralizing antibodies against hepatitis C virus (HCV), but the mechanisms of this neutralization in the cell-culture-infectious genotype 2a strain JFH1 HCV virus (HCVcc) system are unknown. Two rabbit polyclonal sera, R1020 and R140, recognizing the HVR1 of the genotype 1a isolates H77c and Glasgow (Gla), respectively, and a Gla HVR1-specific mouse mAb AP213 have been described previously. However, attempts to generate of antibodies to the JFH1 HVR1 were unsuccessful. Therefore, this study produced chimeric JFH1 HCVcc viruses harbouring the H77c or Gla HVR1 to assess the reactivity of antibodies to this region and their effects on virus infectivity. The inter-genotypic HVR1 swap did not significantly affect virus infectivity. The genotype 1a HVR1-specific antibodies neutralized chimeric viruses in an isolate-dependent manner, underlining the role of HVR1 in HCV infection. The neutralizing antibodies reacted mainly with the C-terminal portion of HVR1, and detailed mapping identified A17, F20 and Q21 in the Gla HVR1 sequence and T21 (and possibly L20) in the corresponding H77c sequence as key epitope residues for AP213 and R140, and R1020, respectively. Importantly, none of the antibodies inhibited in vitro binding of viral envelope glycoproteins to the best-characterized HCV receptor, CD81, or to the glycosaminoglycan attachment factors. However, the HVR1 antibodies were capable of post-attachment neutralization. Overall, this study emphasizes the role of HVR1 in HCVcc entry and provides new tools to study this region further in the context of complete virions.
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Affiliation(s)
- Gabrielle Vieyres
- MRC – University of Glasgow Centre for Virus Research, University of Glasgow, Church Street, Glasgow G11 5JR, UK
- Institut Pasteur de Lille, Center for Infection & Immunity of Lille (CIIL), F-59019 Lille, France
- Inserm U1019, F-59019 Lille, France
- CNRS UMR8204, F-59021 Lille, France
- Université Lille Nord de France, F-59000 Lille, France
| | - Jean Dubuisson
- Institut Pasteur de Lille, Center for Infection & Immunity of Lille (CIIL), F-59019 Lille, France
- Inserm U1019, F-59019 Lille, France
- CNRS UMR8204, F-59021 Lille, France
- Université Lille Nord de France, F-59000 Lille, France
| | - Arvind H. Patel
- MRC – University of Glasgow Centre for Virus Research, University of Glasgow, Church Street, Glasgow G11 5JR, UK
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Systematic analysis of attenuated Coxsackievirus expressing a foreign gene as a viral vaccine vector. Vaccine 2010; 28:1234-40. [DOI: 10.1016/j.vaccine.2009.11.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 10/17/2009] [Accepted: 11/09/2009] [Indexed: 11/18/2022]
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11
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Hughes MG, Rosen HR. Human liver transplantation as a model to study hepatitis C virus pathogenesis. Liver Transpl 2009; 15:1395-411. [PMID: 19877210 PMCID: PMC2954677 DOI: 10.1002/lt.21866] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hepatitis C is a leading etiology of liver cancer and a leading reason for liver transplantation. Although new therapies have improved the rates of sustained response, a large proportion of patients (approximately 50%) fail to respond to antiviral treatment, thus remaining at risk for disease progression. Although chimpanzees have been used to study hepatitis C virus biology and treatments, their cost is quite high, and their use is strictly regulated; indeed, the National Institutes of Health no longer supports the breeding of chimpanzees for study. The development of hepatitis C virus therapies has been hindered by the relative paucity of small animal models for studying hepatitis C virus pathogenesis. This review presents the strengths of human liver transplantation and highlights the advances derived from this model, including insights into viral kinetics and quasispecies, viral receptor binding and entry, and innate and adaptive immunity. Moreover, consideration is given to current and emerging antiviral therapeutic approaches based on translational research results.
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Affiliation(s)
- Michael G. Hughes
- Department of Surgery, Medical University of South Carolina, Charleston, SC
| | - Hugo R. Rosen
- Department of Medicine, Divisions of Gastroenterology & Hepatology and Liver Transplantation; University of Colorado Health Sciences Center & National Jewish Hospital, and Denver VA
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Cocquerel L, Voisset C, Dubuisson J. Hepatitis C virus entry: potential receptors and their biological functions. J Gen Virol 2006; 87:1075-1084. [PMID: 16603507 DOI: 10.1099/vir.0.81646-0] [Citation(s) in RCA: 141] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Several cellular molecules have been identified as putative receptors forHepatitis C virus(HCV): CD81 tetraspanin, scavenger receptor class B type I (SR-BI), mannose-binding lectins DC-SIGN and L-SIGN, low-density lipoprotein receptor, heparan sulphate proteoglycans and the asialoglycoprotein receptor. Due to difficulties in propagating HCV in cell culture, most of these molecules have been identified by analysing their interaction with a soluble, truncated form of HCV glycoprotein E2. A recent major step in investigating HCV entry was the development of pseudoparticles (HCVpp), consisting of unmodified HCV envelope glycoproteins assembled onto retroviral core particles. This system has allowed the investigation of the role of candidate receptors in the early steps of the HCV life cycle and the data obtained can now be confirmed with the help of a newly developed cell-culture system that allows efficient amplification of HCV (HCVcc). Interestingly, CD81 and SR-BI have been shown to play direct roles in HCVpp and/or HCVcc entry. However, co-expression of CD81 and SR-BI in non-hepatic cell lines does not lead to HCVpp entry, indicating that other molecule(s), expressed only in hepatic cells, are necessary for HCV entry. In this review, the molecules that have been proposed as potential HCV receptors are described and the experimental data indicating that CD81 and SR-BI are potentially involved in HCV entry are presented.
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Affiliation(s)
- Laurence Cocquerel
- CNRS-UMR8161, Institut de Biologie de Lille, Institut Pasteur de Lille, 1 rue Calmette, BP447, 59021 Lille cedex, France
| | - Cécile Voisset
- CNRS-UMR8161, Institut de Biologie de Lille, Institut Pasteur de Lille, 1 rue Calmette, BP447, 59021 Lille cedex, France
| | - Jean Dubuisson
- CNRS-UMR8161, Institut de Biologie de Lille, Institut Pasteur de Lille, 1 rue Calmette, BP447, 59021 Lille cedex, France
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Callens N, Ciczora Y, Bartosch B, Vu-Dac N, Cosset FL, Pawlotsky JM, Penin F, Dubuisson J. Basic residues in hypervariable region 1 of hepatitis C virus envelope glycoprotein e2 contribute to virus entry. J Virol 2006; 79:15331-41. [PMID: 16306604 PMCID: PMC1316016 DOI: 10.1128/jvi.79.24.15331-15341.2005] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The N terminus of hepatitis C virus (HCV) envelope glycoprotein E2 contains a hypervariable region (HVR1) which has been proposed to play a role in viral entry. Despite strong amino acid variability, HVR1 is globally basic, with basic residues located at specific sequence positions. Here we show by analyzing a large number of HVR1 sequences that the frequency of basic residues at each position is genotype dependent. We also used retroviral pseudotyped particles (HCVpp) harboring genotype 1a envelope glycoproteins to study the role of HVR1 basic residues in entry. Interestingly, HCVpp infectivity globally increased with the number of basic residues in HVR1. However, a shift in position of some charged residues also modulated HCVpp infectivity. In the absence of basic residues, infectivity was reduced to the same level as that of a mutant deleted of HVR1. We also analyzed the effect of these mutations on interactions with some potential HCV receptors. Recognition of CD81 was not affected by changes in the number of charged residues, and we did not find a role for heparan sulfates in HCVpp entry. The involvement of the scavenger receptor class B type I (SR-BI) was indirectly analyzed by measuring the enhancement of infectivity of the mutants in the presence of the natural ligand of SR-BI, high-density lipoproteins (HDL). However, no correlation between the number of basic residues within HVR1 and HDL enhancement effect was observed. Despite the lack of evidence of the involvement of known potential receptors, our results demonstrate that the presence of basic residues in HVR1 facilitates virus entry.
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Affiliation(s)
- Nathalie Callens
- Unité Hépatite C, CNRS-UPR2511, Institut de Biologie de Lille, 1 rue Calmette, BP447, 59021 Lille cedex, France
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14
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Schofield DJ, Bartosch B, Shimizu YK, Allander T, Alter HJ, Emerson SU, Cosset FL, Purcell RH. Human monoclonal antibodies that react with the E2 glycoprotein of hepatitis C virus and possess neutralizing activity. Hepatology 2005; 42:1055-62. [PMID: 16250048 DOI: 10.1002/hep.20906] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Active and/or passive immunoprophylaxis against hepatitis C virus (HCV) remain unachieved goals. Monoclonal antibodies might provide one approach to protection. We derived human monoclonal antibodies from the bone marrow of a patient with a well-controlled HCV infection of 22 years duration. Five distinct antibodies reactive with the E2 glycoprotein of the homologous 1a strain of HCV were recovered as antigen-binding fragments (FAbs). They demonstrated affinity constants as high as 2 nanomolar. "Neutralization of binding" titers paralleled the affinity constants. All five FAbs reacted with soluble E2 protein only in nonreducing gels, indicating that the relevant epitopes were conformational. The FAbs could be divided into two groups, based on competition analysis. Three of the FAbs neutralized the infectivity of pseudotyped virus particles (pp) bearing the envelope glycoproteins of the homologous HCV strain (genotype 1a). The three FAbs also neutralized genotype 1b pp and one also neutralized genotype 2a pp. In conclusion, one or more of these monoclonal antibodies may be useful in preventing infections by HCV belonging to genotype 1 or 2, the most medically important genotypes worldwide.
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Affiliation(s)
- Darren J Schofield
- Hepatitis Viruses Section, Laboratory of Infectious Diseases, NIAID, National Institutes of Health, Bethesda, MD 20892-8009, USA
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15
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Beyene A, Basu A, Meyer K, Ray R. Influence of N-linked glycans on intracellular transport of hepatitis C virus E1 chimeric glycoprotein and its role in pseudotype virus infectivity. Virology 2004; 324:273-85. [PMID: 15207615 DOI: 10.1016/j.virol.2004.03.039] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2004] [Revised: 03/10/2004] [Accepted: 03/23/2004] [Indexed: 12/23/2022]
Abstract
We have previously reported a functional role associated with hepatitis C virus (HCV) E1 glycoprotein using vesicular stomatitis virus (VSV)/HCV pseudotype. In this study, we have investigated the role of glycosylation upon intracellular transport of chimeric E1-G, and in infectivity of the pseudotyped virus. Interestingly, surface expressed E1-G exhibited sensitivity to Endoglycosidase H (Endo H) treatment, which was similar to full-length E1, suggesting that additional complex oligosaccharides were not added while E1-G was in transit from the endoplasmic reticulum (ER) to the mammalian cell surface. As a next step, each of the four potential N-linked glycosylation sites located at amino acid position 196, 209, 234, or 305 of the E1 ectodomain were mutated separately (asparagine --> glutamine), or in some combination. FACS analysis suggested that mutation(s) of the glycosylation sites affect the translocation of E1-G to the cell surface to different extents, with no single site being particularly essential. VSV pseudotype virus generated from glycosylation mutants exhibited a decrease in titer with an increasing number of mutations at the glycosylation sites on chimeric E1-G. In a separate experiment, N-glycosidase F treatment of pseudotype generated from the already synthesized E1-G or its mutants decreased virus titer by approximately 35%, and the neutralization activity of patient sera was not significantly altered with N-glycosidase F-treated pseudotype virus. Taken together, our results suggested that E1-G does not add complex sugar moieties during transport to the cell surface and retain the glycosylation profile of its parental E1 sequence. Additionally, the removal of glycans from the E1-G reduced, but does not completely impair, virus infectivity.
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Affiliation(s)
- Aster Beyene
- Department of Internal Medicine, Saint Louis University, 3635 Vista Avenue, St. Louis, MO 63110, USA
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16
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Basu A, Beyene A, Meyer K, Ray R. The hypervariable region 1 of the E2 glycoprotein of hepatitis C virus binds to glycosaminoglycans, but this binding does not lead to infection in a pseudotype system. J Virol 2004; 78:4478-86. [PMID: 15078928 PMCID: PMC387685 DOI: 10.1128/jvi.78.9.4478-4486.2004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Accepted: 01/09/2004] [Indexed: 12/17/2022] Open
Abstract
The hypervariable region 1 (HVR1) of hepatitis C virus (HCV) E2 envelope glycoprotein is a 27-amino-acid sequence located at its N terminus. In this study, we investigated the functional role of HVR1 for interaction with the mammalian cell surface. The C-terminal truncated E2 glycoprotein was appended to a transmembrane domain and cytoplasmic tail of vesicular stomatitis virus (VSV) G protein for generation of the chimeric E2-G gene construct. A deletion of the HVR1 sequence from E2 was created for the construction of E2DeltaHVR1-G. Pseudotype virus, generated separately by infection of a stable cell line expressing E2-G or E2DeltaHVR1-G with a temperature-sensitive mutant of VSV (VSVts045), displayed unique functional properties compared to VSVts045 as a negative control. Virus generated from E2DeltaHVR1-G had a reduced plaquing efficiency ( approximately 50%) in HepG2 cells compared to that for the E2-G virus. Cells prior treated with pronase (0.5 U/ml) displayed a complete inhibition of infectivity of the E2DeltaHVR1-G or E2-G pseudotypes, whereas heparinase I treatment (8 U/ml) of cells reduced 40% E2-G pseudotype virus titer only. E2DeltaHVR1-G pseudotypes were not sensitive to heparin (6 to 50 micro g/ml) as an inhibitor of plaque formation compared to the E2-G pseudotype virus. Although the HVR1 sequence itself does not match with the known heparin-binding domain, a synthetic peptide representing 27 amino acids of the E2 HVR1 displayed a strong affinity for heparin in an enzyme-linked immunosorbent assay. This binding was competitively inhibited by a peptide from the V3 loop of a human immunodeficiency virus glycoprotein subunit (gp120) known to bind with cell surface heparin. Taken together, our results suggest that the HVR1 of E2 glycoprotein binds to the cell surface proteoglycans and may facilitate virus-host interaction for replication cycle of HCV.
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Affiliation(s)
- Arnab Basu
- Department of Internal Medicine, Saint Louis University, St. Louis, Missouri 63110, USA
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17
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Liu QP, Jia ZS, Du DW, Li GY, Pan L, Wei X, Luo XD, Wang QC. Construction of human CD81 eukaryotic expression vector and expression of the gene segment in COS-7 cell line. Shijie Huaren Xiaohua Zazhi 2004; 12:590-593. [DOI: 10.11569/wcjd.v12.i3.590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To construct a human CD81 eukaryotic expression vector and to analyze the expression of CD81 in COS-7 cells.
METHODS: CD81 gene from the pMD18-T-CD81 vector with double-enzyme digestion was cloned into the pVAX1 eukaryotic expression vector, named pVAX1-CD81. The recombinant vector pVAX1-CD81 and pVAX1 as controls were transfected into COS-7 cells by lipofectamine, and the transient expression product on the transfected cells was analyzed with anti-CD81 monoclonal antibody by indirect immunofluorescence assay (IFA).
RESULTS: The identification of the eukaryotic expression vector pVAX1-CD81 by PCR and restriction enzyme analysis showed that CD81 gene was rightly inserted into the vector; and the product of the CD81 gene was successfully expressed on surface of COS-7 cells.
CONCLUSION: The eukaryotic expression vector with CD81 gene is constructed and efficiently expressed in COS-7 cells. The results indicate that the transfected CD81 cells will need to further studies on the roles of CD81 in the process of HCV infection and entrance to cells.
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18
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VanCompernolle SE, Wiznycia AV, Rush JR, Dhanasekaran M, Baures PW, Todd SC. Small molecule inhibition of hepatitis C virus E2 binding to CD81. Virology 2003; 314:371-80. [PMID: 14517089 DOI: 10.1016/s0042-6822(03)00406-9] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The hepatitis C virus (HCV) is a causal agent of chronic liver infection, cirrhosis, and hepatocellular carcinoma infecting more than 170 million people. CD81 is a receptor for HCV envelope glycoprotein E2. Although the binding of HCV-E2 with CD81 is well documented the role of this interaction in the viral life cycle remains unclear. Host specificity and mutagenesis studies suggest that the helix D region of CD81 mediates binding to HCV-E2. Structural analysis of CD81 has enabled the synthesis of small molecules designed to mimic the space and hydrophobic features of the solvent-exposed face on helix D. Utilizing a novel bis-imidazole scaffold a series of over 100 compounds has been synthesized. Seven related, imidazole-based compounds were identified that inhibit binding of HCV-E2 to CD81. The inhibitory compounds have no short-term effect on cellular expression of CD81 or other tetraspanins, do not disrupt CD81 associations with other cell surface proteins, and bind reversibly to HCV-E2. These results provide an important proof of concept that CD81-based mimics can disrupt binding of HCV-E2 to CD81.
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Affiliation(s)
- Scott E VanCompernolle
- Kansas State University, Program in Molecular and Developmental Biology, Division of Biology, Manhattan, KS 66506, USA
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19
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Abstract
Hepatitis C virus (HCV) is the leading cause of chronic liver disease worldwide. HCV is also the major cause of mixed cryoglobulinemia, a B-lymphocyte proliferative disorder. Direct experimentation with native viral proteins is not feasible. Truncated versions of recombinant E2 envelope proteins, used as surrogates for viral particles, were shown to bind specifically to human CD81. However, truncated E2 may not fully mimic the surface of HCV virions because the virus encodes two envelope glycoproteins that associate with each other as E1E2 heterodimers. Here we show that E1E2 complexes efficiently bind to CD81 whereas truncated E2 is a weak binder, suggesting that truncated E2 is probably not the best tool with which to study cellular interactions. To gain better insight into virus-cell interactions, we developed a method by which to isolate E1E2 complexes that are properly folded. We demonstrate that purified E1E2 heterodimers bind to cells in a CD81-dependent manner. Furthermore, engagement of B cells by purified E1E2 heterodimers results in their aggregation and in protein tyrosine phosphorylation, a hallmark of B-cell activation. These studies provide a possible clue to the etiology of HCV-associated B-cell lymphoproliferative diseases. They also delineate a method by which to isolate biologically functional E1E2 complexes for the study of virus-host cell interaction in other cell types.
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Affiliation(s)
- Laurence Cocquerel
- Department of Medicine, Stanford University Medical Center, Stanford, California 94305, USA
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20
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Abstract
Hepatitis C virus encodes two envelope glycoproteins, E1 and E2, that are released from a polyprotein precursor after cleavage by host signal peptidase(s). These proteins contain a large N-terminal ectodomain and a C-terminal transmembrane domain, and they assemble as a noncovalent heterodimer. The transmembrane domains of hepatitis C virus envelope glycoproteins have been shown to be multifunctional: (1) they are membrane anchors, (2) they bear ER retention signals, (3) they contain a signal sequence function, and (4) they are involved in E1-E2 heterodimerisation. Due to these multiple functions, the topology adopted by these transmembrane domains has given rise to much controversy. They are less than 30 amino acid residues long and are composed of two stretches of hydrophobic residues separated by a short segment containing one or two fully conserved positively charged residues. The presence of a signal sequence function in the C-terminal half of the transmembrane domains of E1 and E2 had suggested that these domains are composed of two membrane spanning segments. However, the two hydrophobic stretches are too short to make two membrane spanning alpha-helices. These discrepancies can now be explained by a dynamic model, based on experimental data, describing the early steps of the biogenesis of hepatitis C virus envelope glycoproteins. In this model, the transmembrane domains of E1 and E2 form a hairpin structure before cleavage by a signal peptidase, and a reorientation of the second hydrophobic stretch occurs after cleavage to produce a single membrane spanning domain.
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Affiliation(s)
- Anne Op De Beeck
- CNRS-UPR2511, Institut de Biologie de Lille & Institut Pasteur de Lille, 59021 Lille, France
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21
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Kien F, Abraham JD, Schuster C, Kieny MP. Analysis of the subcellular localization of hepatitis C virus E2 glycoprotein in live cells using EGFP fusion proteins. J Gen Virol 2003; 84:561-566. [PMID: 12604806 DOI: 10.1099/vir.0.18927-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Hepatitis C virus (HCV) E1 and E2 glycoproteins assemble intracellularly to form a non-covalently linked heterodimer, which is retained in the endoplasmic reticulum (ER). To study the subcellular localization of E2 in live cells, the enhanced green fluorescent protein (EGFP) was fused to the N terminus of E2. Using fluorescence and confocal microscopy, we have confirmed that E2 is located in the ER, where budding of HCV virions is thought to occur. Immunoprecipitation experiments using a conformation-sensitive antibody and a GST pull-down assay showed that fusion of EGFP to E2 interferes neither with its heterodimeric assembly with E1, nor with proper folding of the ectodomain, nor with the capacity of E2 to interact with human CD81, indicating that the EGFP-E2 fusion protein is functional. As a tool to study binding of E2 to target cells, we also described the expression of an EGFP-E2 fusion protein at the cell surface.
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Affiliation(s)
- François Kien
- INSERM U544, Institut de Virologie, 3 rue Koeberlé, 67000 Strasbourg, France
| | - Jean-Daniel Abraham
- INSERM U544, Institut de Virologie, 3 rue Koeberlé, 67000 Strasbourg, France
| | - Catherine Schuster
- INSERM U544, Institut de Virologie, 3 rue Koeberlé, 67000 Strasbourg, France
| | - Marie Paule Kieny
- INSERM U544, Institut de Virologie, 3 rue Koeberlé, 67000 Strasbourg, France
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22
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Cocquerel L, Quinn ER, Flint M, Hadlock KG, Foung SKH, Levy S. Recognition of native hepatitis C virus E1E2 heterodimers by a human monoclonal antibody. J Virol 2003; 77:1604-9. [PMID: 12502876 PMCID: PMC140849 DOI: 10.1128/jvi.77.2.1604-1609.2003] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The majority of hepatitis C virus (HCV)-infected individuals progress from acute to chronic disease, despite the presence of a strong humoral immune response to the envelope glycoproteins E1 and E2. When expressed in mammalian cells, E1 and E2 form both noncovalently linked E1E2 heterodimers, believed to be properly folded, and disulfide-linked, high-molecular-weight aggregates that are misfolded. Previously, we identified 10 human monoclonal antibodies (HMAbs) that bind E2 glycoproteins from different genotypes. Here we demonstrate that one of these HMAbs, CBH-2, is unique in its ability to distinguish between properly folded and misfolded envelope proteins. This HMAb recognizes HCV-E2 only when complexed with E1. The E1E2 complexes recognized by CBH-2 are noncovalently linked heterodimers and not misfolded disulfide-linked, high-molecular-weight aggregates. The E1E2 heterodimers seen by CBH-2 no longer associate with the endoplasmic reticulum chaperone calnexin and are likely to represent the prebudding form of the HCV virion.
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Affiliation(s)
- Laurence Cocquerel
- Department of Medicine/Division of Oncology, Stanford University Medical Center, California 94305, USA
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23
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Affiliation(s)
- Xavier Forns
- Liver Unit, Institut de Malalties Digestives, Hospital Clínic, Villaroel 170, Barcelona 08036, Spain.
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24
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Sanz-Cameno P, Borque MJ, García-Buey L, Moreno-Otero R. [Interaction of the hepatitis C virus with the cellular membrane]. GASTROENTEROLOGIA Y HEPATOLOGIA 2002; 25:521-5. [PMID: 12361536 DOI: 10.1016/s0210-5705(02)70304-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- P Sanz-Cameno
- Unidad de Biología Molecular, Hospital Universitario de la Princesa, Universidad Autónoma de Madrid, España
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25
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Op De Beeck A, Cocquerel L, Dubuisson J. Biogenesis of hepatitis C virus envelope glycoproteins. J Gen Virol 2001; 82:2589-2595. [PMID: 11602769 DOI: 10.1099/0022-1317-82-11-2589] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Anne Op De Beeck
- Equipe Hépatite C, CNRS-FRE2369, IBL/Institut Pasteur de Lille, 1 rue Calmette, BP 447, 59021 Lille cedex, France1
| | - Laurence Cocquerel
- Equipe Hépatite C, CNRS-FRE2369, IBL/Institut Pasteur de Lille, 1 rue Calmette, BP 447, 59021 Lille cedex, France1
| | - Jean Dubuisson
- Equipe Hépatite C, CNRS-FRE2369, IBL/Institut Pasteur de Lille, 1 rue Calmette, BP 447, 59021 Lille cedex, France1
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26
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Abstract
Since the genomic sequence of HCV was determined, significant progress has been made towards understanding the functions of the HCV-encoded proteins, despite the lack of an efficient in-vitro replication system or convenient small-animal model. The identity of the receptor for HCV remains elusive, however. Low-density lipoprotein receptor, CD81, and GAGs may all act as receptors for HCV, either sequentially or by different viral quasispecies. Recent work using pseudotypic VSV bearing E1 or E2 chimeric molecules showed that entry of the E1 pseudotype can be inhibited by recombinant LDLr, whereas the E2 pseudotype is more sensitive to inhibition by recombinant CD81 or heparin. These results suggest that E1 and E2 may be responsible for interactions with different cellular molecules. It is also conceivable that additional, yet unidentified, cellular proteins are involved in viral binding and entry. Intriguingly, the reports of HCV-RNA associated with PBMC suggest that HCV infection may not be restricted to hepatocytes. Thus, separate reservoirs of virus may exist, and HCV may use different receptors to access these different cell types.
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Affiliation(s)
- M Flint
- Division of Oncology, Department of Medicine, Stanford University Medical Center, Stanford, California, USA
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27
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Owsianka A, Clayton RF, Loomis-Price LD, McKeating JA, Patel AH. Functional analysis of hepatitis C virus E2 glycoproteins and virus-like particles reveals structural dissimilarities between different forms of E2. J Gen Virol 2001; 82:1877-1883. [PMID: 11457993 DOI: 10.1099/0022-1317-82-8-1877] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Structure-function analysis of the hepatitis C virus (HCV) envelope glycoproteins, E1 and E2, has been difficult due to the unavailability of HCV virions. Truncated soluble forms of E2 have been used as models to study virus interaction with the putative HCV receptor CD81, but they may not fully mimic E2 structures on the virion. Here, we compared the CD81-binding characteristics of truncated E2 (E2(660)) and full-length (FL) E1E2 complex expressed in mammalian cells, and of HCV virus-like particles (VLPs) generated in insect cells. All three glycoprotein forms interacted with human CD81 in an in vitro binding assay, allowing us to test a panel of well-characterized anti-E2 monoclonal antibodies (MAbs) for their ability to inhibit the glycoprotein-CD81 interaction. MAbs specific for E2 amino acid (aa) regions 396-407, 412-423 and 528-535 blocked binding to CD81 of all antigens tested. However, MAbs specific for regions 432-443, 436-443 and 436-447 inhibited the interaction of VLPs, but not of E2(660) or the FL E1E2 complex with CD81, indicating the existence of structural differences amongst the E2 forms. These findings underscore the need to carefully select an appropriate ligand for structure-function analysis.
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Affiliation(s)
- Ania Owsianka
- MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, UK1
| | - Reginald F Clayton
- MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, UK1
| | | | - Jane A McKeating
- University of Reading, School of Animal & Microbial Sciences, PO Box 228, Reading, UK3
| | - Arvind H Patel
- MRC Virology Unit, Institute of Virology, Church Street, Glasgow G11 5JR, UK1
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28
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Seong YR, Choi S, Lim JS, Lee CH, Lee CK, Im DS. Immunogenicity of the E1E2 proteins of hepatitis C virus expressed by recombinant adenoviruses. Vaccine 2001; 19:2955-64. [PMID: 11282207 DOI: 10.1016/s0264-410x(00)00534-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The E1 and E2 proteins of hepatitis C virus (HCV) are believed to be the viral envelope glycoproteins that are major candidate antigens for HCV vaccine development. We reported previously that the replication-competent recombinant adenovirus encoding core-E1-E2 genes of HCV (Ad/HCV) produces serologically reactive E1 and E2 proteins forming a heterodimer in substantial amounts. Here, we examined immunogenicity of the E1E2 proteins copurified from HeLa cells infected with Ad/HCV virus in mice. Furthermore, we constructed a replication-defective recombinant adenovirus encoding the core-E1-E2 genes of HCV (Ad.CMV.HCV) and examined immunogenicity of the virus in mice. The mice immunized intraperitoneally with the copurified E1E2 proteins induced mainly antibodies to E2, but not to E1 by Western blot analysis. The sera of mice immunized with the E1E2 inhibited the binding of E2 protein to the major extracellular loop of human CD81. E2-specific cytotoxic T cells (CTLs), but not antibodies to the E1E2 antigens were induced in the mice intramuscularly immunized with Ad.CMV.HCV virus. When immunized with both Ad.CMV.HCV virus and the E1E2, mice elicited E2-specific CTLs and antibodies to the E1E2 antigens. The results suggest that immunization of Ad.CMV.HCV virus combined with E2 protein is an effective modality to induce humoral as well as cellular immune response to E2 antigen.
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Affiliation(s)
- Y R Seong
- Cell Biology Laboratory, Korea Research Institute of Bioscience and Biotechnology, Yusong PO Box 115, Taejon 305-600, South Korea
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29
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Forns X. [Molecular biology of hepatitis C virus: implications for the development of new therapies and prophylactic vaccine]. Med Clin (Barc) 2001; 116:191-7. [PMID: 11222177 DOI: 10.1016/s0025-7753(01)71766-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- X Forns
- Unidad de Hepatología. Institut de Malalties Digestives. Hospital Clínic de Barcelona
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30
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Allander T, Forns X, Emerson SU, Purcell RH, Bukh J. Hepatitis C virus envelope protein E2 binds to CD81 of tamarins. Virology 2000; 277:358-67. [PMID: 11080483 DOI: 10.1006/viro.2000.0617] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Since recombinant envelope glycoprotein E2 of hepatitis C virus (HCV) binds to CD81 on human and chimpanzee cells, it has been suggested that CD81 may be a receptor for HCV. Humans and chimpanzees are the only species known to be susceptible to HCV infection. E2 has been reported not to bind to CD81 of the African green monkey, mouse, or rat, suggesting that binding of HCV to CD81 is species specific and may determine susceptibility to infection with HCV. We investigated the interaction between E2 of HCV and CD81 of tamarins, a group of small New World monkeys frequently used for the study of human viruses. Tamarins are not susceptible to HCV infection. Nonetheless, we found that three different forms of HCV E2 (intracellular, secreted, and cell surface-displayed) bound more efficiently to recombinant tamarin CD81 than to human CD81, as determined by ELISA and immunofluorescence. The affinity of the interaction was approximately 10-fold higher for tamarin than for human CD81. Binding of E2 to CD81 on cultured or primary tamarin cells was demonstrated by flow cytometry. In contrast to previous reports, there was also a low-affinity interaction between E2 and African green monkey CD81. Thus, the HCV E2 interaction with CD81 is not limited to humans and chimpanzees and does not predict susceptibility to HCV infection.
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Affiliation(s)
- T Allander
- Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892-0740, USA
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31
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Forns X, Thimme R, Govindarajan S, Emerson SU, Purcell RH, Chisari FV, Bukh J. Hepatitis C virus lacking the hypervariable region 1 of the second envelope protein is infectious and causes acute resolving or persistent infection in chimpanzees. Proc Natl Acad Sci U S A 2000; 97:13318-23. [PMID: 11078521 PMCID: PMC27222 DOI: 10.1073/pnas.230453597] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Persistent infection with hepatitis C virus (HCV) is among the leading causes of chronic liver disease. Previous studies suggested that genetic variation in hypervariable region 1 (HVR1) of the second envelope protein, possibly in response to host immune pressure, influences the outcome of HCV infection. In the present study, a chimpanzee transfected intrahepatically with RNA transcripts of an infectious HCV clone (pCV-H77C) from which HVR1 was deleted became infected; the DeltaHVR1 virus was subsequently transmitted to a second chimpanzee. Infection with DeltaHVR1 virus resulted in persistent infection in the former chimpanzee and in acute resolving infection in the latter chimpanzee. Both chimpanzees developed hepatitis. The DeltaHVR1 virus initially replicated to low titers, but virus titer increased significantly after mutations appeared in the viral genome. Thus, wild-type HCV without HVR1 was apparently attenuated, suggesting a functional role of HVR1. However, our data indicate that HVR1 is not essential for the viability of HCV, the resolution of infection, or the progression to chronicity.
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Affiliation(s)
- X Forns
- Hepatitis Viruses Section and Molecular Hepatitis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Forns X, Payette PJ, Ma X, Satterfield W, Eder G, Mushahwar IK, Govindarajan S, Davis HL, Emerson SU, Purcell RH, Bukh J. Vaccination of chimpanzees with plasmid DNA encoding the hepatitis C virus (HCV) envelope E2 protein modified the infection after challenge with homologous monoclonal HCV. Hepatology 2000; 32:618-25. [PMID: 10960458 DOI: 10.1053/jhep.2000.9877] [Citation(s) in RCA: 123] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hepatitis C virus (HCV) is an important cause of chronic liver disease worldwide. Development of vaccines to prevent HCV infection, or at least prevent progression to chronicity, is a major goal. In mice and rhesus macaques, a DNA vaccine encoding cell-surface HCV-envelope 2 (E2) glycoprotein stimulated stronger immune responses than a vaccine encoding intracellular E2. Therefore, we used DNA encoding surface-expressed E2 to immunize chimpanzees 2768 and 3001. Chimpanzee 3001 developed anti-E2 after the second immunization and antibodies to hypervariable region 1 (HVR1) after the third immunization. Although chimpanzee 2768 had only low levels of anti-E2 after the third immunization, an anamnestic response occurred after HCV challenge. CTL responses to E2 were not detected before challenge, but a strong response was detected after HCV challenge in chimpanzee 2768. An E2-specific CD4+ response was detected in chimpanzee 2768 before challenge and in both chimpanzees postchallenge. Three weeks after the last immunization, animals were challenged with 100 50% chimpanzee-infectious doses (CID(50)) of homologous monoclonal HCV. As a control, a naive chimpanzee was inoculated with 3 CID(50) of the challenge virus. The vaccine did not generate sterilizing immunity because both vaccinated chimpanzees were infected. However, both vaccinated chimpanzees resolved the infection early whereas the control animal became chronically infected. Compared with the control animal, hepatitis appeared earlier in the course of the infection in both vaccinated chimpanzees. Therefore, DNA vaccine encoding cell surface-expressed E2 did not elicit sterilizing immunity in chimpanzees against challenge with a monoclonal homologous virus, but did appear to modify the infection and might have prevented progression to chronicity.
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Affiliation(s)
- X Forns
- Hepatitis Viruses, Laboratory of Infectious Diseases, NIAID, National Institutes of Health, Bethesda, MD
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