1
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Ströh LJ, Krey T. Structural insights into hepatitis C virus neutralization. Curr Opin Virol 2023; 60:101316. [DOI: 10.1016/j.coviro.2023.101316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/12/2023] [Indexed: 03/31/2023]
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2
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Gomez-Escobar E, Roingeard P, Beaumont E. Current Hepatitis C Vaccine Candidates Based on the Induction of Neutralizing Antibodies. Viruses 2023; 15:1151. [PMID: 37243237 PMCID: PMC10220683 DOI: 10.3390/v15051151] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/05/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
The introduction of direct-acting antivirals (DAAs) has revolutionized hepatitis C treatment. Short courses of treatment with these drugs are highly beneficial to patients, eliminating hepatitis C virus (HCV) without adverse effects. However, this outstanding success is tempered by the continuing difficulty of eradicating the virus worldwide. Thus, access to an effective vaccine against HCV is strongly needed to reduce the burden of the disease and contribute to the elimination of viral hepatitis. The recent failure of a T-cell vaccine based on the use of viral vectors expressing the HCV non-structural protein sequences to prevent chronic hepatitis C in drug users has pointed out that the induction of neutralizing antibodies (NAbs) will be essential in future vaccine candidates. To induce NAbs, vaccines must contain the main target of this type of antibody, the HCV envelope glycoproteins (E1 and E2). In this review, we summarize the structural regions in E1 and E2 proteins that are targeted by NAbs and how these proteins are presented in the vaccine candidates currently under development.
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Affiliation(s)
| | - Philippe Roingeard
- Inserm U1259 MAVIVH, Université de Tours and CHRU de Tours, 37000 Tours, France;
| | - Elodie Beaumont
- Inserm U1259 MAVIVH, Université de Tours and CHRU de Tours, 37000 Tours, France;
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3
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Risueño C, Abrescia NGA, Coluzza I. Insights into Hepatitis C Virus E2 core Interactions with Human Cellular Receptor CD81 at Different pHs from Molecular Simulations. J Phys Chem B 2022; 126:8391-8403. [PMID: 36255318 DOI: 10.1021/acs.jpcb.2c04697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Hepatitis C virus (HCV) is the second viral agent that causes the majority of chronic hepatic infections worldwide, following Hepatitis B virus (HBV) infection. HCV infection comprises several steps, from the attachment to the receptors to the delivery of the viral genetic material and replication inside the cells. Tetraspanin CD81 is a key entry factor for HCV as it accompanies the virus during attachment and internalization through clathrin-mediated endocytosis. HCV-CD81 binding takes place through the viral glycoprotein E2. We performed full-atom molecular dynamics simulations reproducing the pH conditions that occur during the viral attachment to the hepatocytes (pH 7.4) and internalization (pH 6.2-4.6). We observed that changing the pH from 7.4 to 6.2 triggers a large conformational change in the binding orientation between E2core (E2core corresponds to residues 412-645 of the viral glycoprotein E2) and CD81LEL (CD81LEL corresponds to residues 112-204 of CD81) that occurs even more rapidly at low pH 4.6. This pH-induced switching mechanism has never been observed before and could allow the virus particles to sense the right moment during the maturation of the endosome to start fusion.
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Affiliation(s)
- Cristina Risueño
- Structure and Cell Biology of Viruses Lab, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio 48160, Spain.,Computational Biophysics Lab, Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramón 182, Donostia-San Sebastián 20014, Spain
| | - Nicola G A Abrescia
- Structure and Cell Biology of Viruses Lab, Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Derio 48160, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid 28029, Spain.,Basque Foundation for Science, IKERBASQUE, Bilbao 48009, Spain
| | - Ivan Coluzza
- Computational Biophysics Lab, Center for Cooperative Research in Biomaterials (CIC biomaGUNE), Basque Research and Technology Alliance (BRTA), Paseo de Miramón 182, Donostia-San Sebastián 20014, Spain.,Basque Foundation for Science, IKERBASQUE, Bilbao 48009, Spain.,Computational Biophysics Lab, Basque Center for Materials, Applications and Nanostructures (BCMaterials), Buil. Martina Casiano, Pl. 3 Parque Científico UPV/EHU Barrio Sarriena, Leioa 48940, Spain
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4
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Stejskal L, Kalemera MD, Lewis CB, Palor M, Walker L, Daviter T, Lees WD, Moss DS, Kremyda-Vlachou M, Kozlakidis Z, Gallo G, Bailey D, Rosenberg W, Illingworth CJR, Shepherd AJ, Grove J. An entropic safety catch controls hepatitis C virus entry and antibody resistance. eLife 2022; 11:e71854. [PMID: 35796426 PMCID: PMC9333995 DOI: 10.7554/elife.71854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 06/28/2022] [Indexed: 11/24/2022] Open
Abstract
E1 and E2 (E1E2), the fusion proteins of Hepatitis C Virus (HCV), are unlike that of any other virus yet described, and the detailed molecular mechanisms of HCV entry/fusion remain unknown. Hypervariable region-1 (HVR-1) of E2 is a putative intrinsically disordered protein tail. Here, we demonstrate that HVR-1 has an autoinhibitory function that suppresses the activity of E1E2 on free virions; this is dependent on its conformational entropy. Thus, HVR-1 is akin to a safety catch that prevents premature triggering of E1E2 activity. Crucially, this mechanism is turned off by host receptor interactions at the cell surface to allow entry. Mutations that reduce conformational entropy in HVR-1, or genetic deletion of HVR-1, turn off the safety catch to generate hyper-reactive HCV that exhibits enhanced virus entry but is thermally unstable and acutely sensitive to neutralising antibodies. Therefore, the HVR-1 safety catch controls the efficiency of virus entry and maintains resistance to neutralising antibodies. This discovery provides an explanation for the ability of HCV to persist in the face of continual immune assault and represents a novel regulatory mechanism that is likely to be found in other viral fusion machinery.
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Affiliation(s)
- Lenka Stejskal
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
| | - Mphatso D Kalemera
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Charlotte B Lewis
- MRC-University of Glasgow Centre for Virus ResearchGlasgowUnited Kingdom
| | - Machaela Palor
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Lucas Walker
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Tina Daviter
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
- Shared Research Facilities, The Institute of Cancer ResearchLondonUnited Kingdom
| | - William D Lees
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
| | - David S Moss
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
| | | | - Zisis Kozlakidis
- International Agency for Research on Cancer, World Health OrganizationLyonFrance
| | | | | | - William Rosenberg
- Division of Medicine, Institute for Liver and Digestive Health, University College LondonLondonUnited Kingdom
| | - Christopher JR Illingworth
- MRC-University of Glasgow Centre for Virus ResearchGlasgowUnited Kingdom
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
- Institut für Biologische Physik, Universität zu KölnCologneGermany
- MRC Biostatistics Unit, University of CambridgeCambridgeUnited Kingdom
| | - Adrian J Shepherd
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
| | - Joe Grove
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
- MRC-University of Glasgow Centre for Virus ResearchGlasgowUnited Kingdom
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5
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Eisfeld HS, Simonis A, Winter S, Chhen J, Ströh LJ, Krey T, Koch M, Theobald SJ, Rybniker J. Viral Glycoproteins Induce NLRP3 Inflammasome Activation and Pyroptosis in Macrophages. Viruses 2021; 13:v13102076. [PMID: 34696506 PMCID: PMC8538122 DOI: 10.3390/v13102076] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 10/10/2021] [Accepted: 10/11/2021] [Indexed: 01/03/2023] Open
Abstract
Infections with viral pathogens are widespread and can cause a variety of different diseases. In-depth knowledge about viral triggers initiating an immune response is necessary to decipher viral pathogenesis. Inflammasomes, as part of the innate immune system, can be activated by viral pathogens. However, viral structural components responsible for inflammasome activation remain largely unknown. Here we analyzed glycoproteins derived from SARS-CoV-1/2, HCMV and HCV, required for viral entry and fusion, as potential triggers of NLRP3 inflammasome activation and pyroptosis in THP-1 macrophages. All tested glycoproteins were able to potently induce NLRP3 inflammasome activation, indicated by ASC-SPECK formation and secretion of cleaved IL-1β. Lytic cell death via gasdermin D (GSDMD), pore formation, and pyroptosis are required for IL-1β release. As a hallmark of pyroptosis, we were able to detect cleavage of GSDMD and, correspondingly, cell death in THP-1 macrophages. CRISPR-Cas9 knockout of NLRP3 and GSDMD in THP-1 macrophages confirmed and strongly support the evidence that viral glycoproteins can act as innate immunity triggers. With our study, we decipher key mechanisms of viral pathogenesis by showing that viral glycoproteins potently induce innate immune responses. These insights could be beneficial in vaccine development and provide new impulses for the investigation of vaccine-induced innate immunity.
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Affiliation(s)
- Hannah S. Eisfeld
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (H.S.E.); (A.S.); (S.W.); (J.C.)
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany;
| | - Alexander Simonis
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (H.S.E.); (A.S.); (S.W.); (J.C.)
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany;
| | - Sandra Winter
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (H.S.E.); (A.S.); (S.W.); (J.C.)
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany;
| | - Jason Chhen
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (H.S.E.); (A.S.); (S.W.); (J.C.)
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany;
| | - Luisa J. Ströh
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany; (L.J.S.); (T.K.)
| | - Thomas Krey
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany; (L.J.S.); (T.K.)
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, 23562 Luebeck, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, 22607 Hamburg, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, 30625 Hannover, Germany
- Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany
| | - Manuel Koch
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany;
- Institute for Dental Research and Oral Musculoskeletal Biology and Center for Biochemistry, Faculty of Medicine and University Hospital Cologne, University of Cologne, Joseph-Stelzmann-Strasse 52, 50931 Cologne, Germany
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50931 Cologne, Germany
| | - Sebastian J. Theobald
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (H.S.E.); (A.S.); (S.W.); (J.C.)
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany;
- Correspondence: (S.J.T.); (J.R.)
| | - Jan Rybniker
- Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Cologne, Germany; (H.S.E.); (A.S.); (S.W.); (J.C.)
- Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital Cologne, University of Cologne, Robert-Koch-Strasse 21, 50931 Cologne, Germany;
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 50931 Cologne, Germany
- Correspondence: (S.J.T.); (J.R.)
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Structural insights into hepatitis C virus receptor binding and entry. Nature 2021; 598:521-525. [PMID: 34526719 PMCID: PMC8542614 DOI: 10.1038/s41586-021-03913-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/13/2021] [Indexed: 02/08/2023]
Abstract
Hepatitis C virus (HCV) infection is a causal agent of chronic liver disease, cirrhosis and hepatocellular carcinoma in humans, and afflicts more than 70 million people worldwide. The HCV envelope glycoproteins E1 and E2 are responsible for the binding of the virus to the host cell, but the exact entry process remains undetermined1. The majority of broadly neutralizing antibodies block interaction between HCV E2 and the large extracellular loop (LEL) of the cellular receptor CD81 (CD81-LEL)2. Here we show that low pH enhances the binding of CD81-LEL to E2, and we determine the crystal structure of E2 in complex with an antigen-binding fragment (2A12) and CD81-LEL (E2-2A12-CD81-LEL); E2 in complex with 2A12 (E2-2A12); and CD81-LEL alone. After binding CD81, residues 418-422 in E2 are displaced, which allows for the extension of an internal loop consisting of residues 520-539. Docking of the E2-CD81-LEL complex onto a membrane-embedded, full-length CD81 places the residues Tyr529 and Trp531 of E2 proximal to the membrane. Liposome flotation assays show that low pH and CD81-LEL increase the interaction of E2 with membranes, whereas structure-based mutants of Tyr529, Trp531 and Ile422 in the amino terminus of E2 abolish membrane binding. These data support a model in which acidification and receptor binding result in a conformational change in E2 in preparation for membrane fusion.
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7
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Structural and Biophysical Characterization of the HCV E1E2 Heterodimer for Vaccine Development. Viruses 2021; 13:v13061027. [PMID: 34072451 PMCID: PMC8227786 DOI: 10.3390/v13061027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 05/20/2021] [Accepted: 05/25/2021] [Indexed: 02/07/2023] Open
Abstract
An effective vaccine for the hepatitis C virus (HCV) is a major unmet medical and public health need, and it requires an antigen that elicits immune responses to multiple key conserved epitopes. Decades of research have generated a number of vaccine candidates; based on these data and research through clinical development, a vaccine antigen based on the E1E2 glycoprotein complex appears to be the best choice. One bottleneck in the development of an E1E2-based vaccine is that the antigen is challenging to produce in large quantities and at high levels of purity and antigenic/functional integrity. This review describes the production and characterization of E1E2-based vaccine antigens, both membrane-associated and a novel secreted form of E1E2, with a particular emphasis on the major challenges facing the field and how those challenges can be addressed.
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8
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Kalemera MD, Capella-Pujol J, Chumbe A, Underwood A, Bull RA, Schinkel J, Sliepen K, Grove J. Optimized cell systems for the investigation of hepatitis C virus E1E2 glycoproteins. J Gen Virol 2021; 102. [PMID: 33147126 PMCID: PMC8116788 DOI: 10.1099/jgv.0.001512] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Great strides have been made in understanding and treating hepatitis C virus (HCV) thanks to the development of various experimental systems including cell-culture-proficient HCV, the HCV pseudoparticle system and soluble envelope glycoproteins. The HCV pseudoparticle (HCVpp) system is a platform used extensively in studies of cell entry, screening of novel entry inhibitors, assessing the phenotypes of clinically observed E1 and E2 glycoproteins and, most pertinently, in characterizing neutralizing antibody breadth induced upon vaccination and natural infection in patients. Nonetheless, some patient-derived clones produce pseudoparticles that are either non-infectious or exhibit infectivity too low for meaningful phenotyping. The mechanisms governing whether any particular clone produces infectious pseudoparticles are poorly understood. Here we show that endogenous expression of CD81, an HCV receptor and a cognate-binding partner of E2, in producer HEK 293T cells is detrimental to the infectivity of recovered HCVpp for most strains. Many HCVpp clones exhibited increased infectivity or had their infectivity rescued when they were produced in 293T cells CRISPR/Cas9 engineered to ablate CD81 expression (293TCD81KO). Clones made in 293TCD81KO cells were antigenically very similar to their matched counterparts made parental cells and appear to honour the accepted HCV entry pathway. Deletion of CD81 did not appreciably increase the recovered titres of soluble E2 (sE2). However, we did, unexpectedly, find that monomeric sE2 made in 293T cells and Freestyle 293-F (293-F) cells exhibit important differences. We found that 293-F-produced sE2 harbours mostly complex-type glycans whilst 293T-produced sE2 displays a heterogeneous mixture of both complex-type glycans and high-mannose or hybrid-type glycans. Moreover, sE2 produced in 293T cells is antigenically superior; exhibiting increased binding to conformational antibodies and the large extracellular loop of CD81. In summary, this work describes an optimal cell line for the production of HCVpp and reveals that sE2 made in 293T and 293-F cells are not antigenic equals. Our findings have implications for functional studies of E1E2 and the production of candidate immunogens.
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Affiliation(s)
- Mphatso D Kalemera
- Institute of Immunity and Transplantation, Division of Infection and Immunity, The Royal Free Hospital, University College London, London, UK
| | - Joan Capella-Pujol
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Ana Chumbe
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Alexander Underwood
- Viral Immunology Systems Program, The Kirby Institute, School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Rowena A Bull
- Viral Immunology Systems Program, The Kirby Institute, School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Janke Schinkel
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Kwinten Sliepen
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Joe Grove
- Institute of Immunity and Transplantation, Division of Infection and Immunity, The Royal Free Hospital, University College London, London, UK
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From Structural Studies to HCV Vaccine Design. Viruses 2021; 13:v13050833. [PMID: 34064532 PMCID: PMC8147963 DOI: 10.3390/v13050833] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/21/2021] [Accepted: 04/28/2021] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) is a serious and growing public health problem despite recent developments of antiviral therapeutics. To achieve global elimination of HCV, an effective cross-genotype vaccine is needed. The failure of previous vaccination trials to elicit an effective cross-reactive immune response demands better vaccine antigens to induce a potent cross-neutralizing response to improve vaccine efficacy. HCV E1 and E2 envelope (Env) glycoproteins are the main targets for neutralizing antibodies (nAbs), which aid in HCV clearance and protection. Therefore, a molecular-level understanding of the nAb responses against HCV is imperative for the rational design of cross-genotype vaccine antigens. Here we summarize the recent advances in structural studies of HCV Env and Env-nAb complexes and how they improve our understanding of immune recognition of HCV. We review the structural data defining HCV neutralization epitopes and conformational plasticity of the Env proteins, and the knowledge applicable to rational vaccine design.
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Meuleman TJ, Cowton VM, Patel AH, Liskamp RMJ. Design and Synthesis of HCV-E2 Glycoprotein Epitope Mimics in Molecular Construction of Potential Synthetic Vaccines. Viruses 2021; 13:v13020326. [PMID: 33672697 PMCID: PMC7924389 DOI: 10.3390/v13020326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/10/2021] [Accepted: 02/13/2021] [Indexed: 12/30/2022] Open
Abstract
Hepatitis C virus remains a global threat, despite the availability of highly effective direct-acting antiviral (DAA) drugs. With thousands of new infections annually, the need for a prophylactic vaccine is evident. However, traditional vaccine design has been unable to provide effective vaccines so far. Therefore, alternative strategies need to be investigated. In this work, a chemistry-based approach is explored towards fully synthetic peptide-based vaccines using epitope mimicry, by focusing on highly effective and conserved amino acid sequences in HCV, which, upon antibody binding, inhibit its bio-activity. Continuous and discontinuous epitope mimics were both chemically synthesized based on the HCV-E2 glycoprotein while using designed fully synthetic cyclic peptides. These cyclic epitope mimics were assembled on an orthogonally protected scaffold. The scaffolded epitope mimics have been assessed in immunization experiments to investigate the elicitation of anti-HCV-E2 glycoprotein antibodies. The neutralizing potential of the elicited antibodies was investigated, representing a first step in employing chemically synthesized epitope mimics as a novel strategy towards vaccine design.
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Affiliation(s)
- Theodorus J. Meuleman
- School of Chemistry, University of Glasgow, Joseph Black Building, University Avenue, Glasgow G12 8QQ, UK;
- Enzytag, Daelderweg, 9 6361 HK Nuth, The Netherlands
| | - Vanessa M. Cowton
- MRC-University of Glasgow Centre for Virus Research, Garscube Campus, Sir Michael Stoker Building, 464 Bearsden Road, Glasgow G61 1QH, UK;
| | - Arvind H. Patel
- MRC-University of Glasgow Centre for Virus Research, Garscube Campus, Sir Michael Stoker Building, 464 Bearsden Road, Glasgow G61 1QH, UK;
- Correspondence: (A.H.P.); (R.M.J.L.)
| | - Rob M. J. Liskamp
- School of Chemistry, University of Glasgow, Joseph Black Building, University Avenue, Glasgow G12 8QQ, UK;
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Faculty of Health, Medicine and Life Sciences, Maastricht UMC, Universiteitssingel 50, 6229 ER Maastricht, The Netherlands
- Chemical Biology and Drug Discovery, Department of Pharmaceutics, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands
- Cristal Therapeutics, Oxfordlaan 55, 6229 EV Maastricht, The Netherlands
- Correspondence: (A.H.P.); (R.M.J.L.)
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Oreste U, Ametrano A, Coscia MR. On Origin and Evolution of the Antibody Molecule. BIOLOGY 2021; 10:biology10020140. [PMID: 33578914 PMCID: PMC7916673 DOI: 10.3390/biology10020140] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/05/2021] [Accepted: 02/07/2021] [Indexed: 12/29/2022]
Abstract
Simple Summary Like many other molecules playing vital functions in animals, the antibody molecule possesses a complex structure with distinctive features. The structure of the basic unit, i.e., the immunoglobulin domain of very ancient origin is substantially simple. However, high complexity resides in the types and numbers of the domains composing the whole molecule. The emergence of the antibody molecule during evolution overturned the effectiveness of the organisms’ defense system. The particular organization of the coding genes, the mechanisms generating antibody diversity, and the plasticity of the overall protein structure, attest to an extraordinary successful evolutionary history. Here, we attempt to trace, across the evolutionary scale, the very early origins of the most significant features characterizing the structure of the antibody molecule and of the molecular mechanisms underlying its major role in recognizing an almost unlimited number of pathogens. Abstract The vertebrate immune system provides a powerful defense because of the ability to potentially recognize an unlimited number of pathogens. The antibody molecule, also termed immunoglobulin (Ig) is one of the major mediators of the immune response. It is built up from two types of Ig domains: the variable domain, which provides the capability to recognize and bind a potentially infinite range of foreign substances, and the constant domains, which exert the effector functions. In the last 20 years, advances in our understanding of the molecular mechanisms and structural features of antibody in mammals and in a variety of other organisms have uncovered the underlying principles and complexity of this fundamental molecule. One notable evolutionary topic is the origin and evolution of antibody. Many aspects have been clearly stated, but some others remain limited or obscure. By considering a wide range of prokaryotic and eukaryotic organisms through a literature survey about the topic, we have provided an integrated view of the emergence of antibodies in evolution and underlined the very ancient origins.
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Affiliation(s)
- Umberto Oreste
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy; (U.O.); (A.A.)
| | - Alessia Ametrano
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy; (U.O.); (A.A.)
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania Luigi Vanvitelli, 81100 Caserta, Italy
| | - Maria Rosaria Coscia
- Institute of Biochemistry and Cell Biology, National Research Council of Italy, Via P. Castellino, 111, 80131 Naples, Italy; (U.O.); (A.A.)
- Correspondence: ; Tel.: +39-081-6132556
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12
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Guest JD, Wang R, Elkholy KH, Chagas A, Chao KL, Cleveland TE, Kim YC, Keck ZY, Marin A, Yunus AS, Mariuzza RA, Andrianov AK, Toth EA, Foung SKH, Pierce BG, Fuerst TR. Design of a native-like secreted form of the hepatitis C virus E1E2 heterodimer. Proc Natl Acad Sci U S A 2021; 118:e2015149118. [PMID: 33431677 PMCID: PMC7826332 DOI: 10.1073/pnas.2015149118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Hepatitis C virus (HCV) is a major worldwide health burden, and a preventive vaccine is needed for global control or eradication of this virus. A substantial hurdle to an effective HCV vaccine is the high variability of the virus, leading to immune escape. The E1E2 glycoprotein complex contains conserved epitopes and elicits neutralizing antibody responses, making it a primary target for HCV vaccine development. However, the E1E2 transmembrane domains that are critical for native assembly make it challenging to produce this complex in a homogenous soluble form that is reflective of its state on the viral envelope. To enable rational design of an E1E2 vaccine, as well as structural characterization efforts, we have designed a soluble, secreted form of E1E2 (sE1E2). As with soluble glycoprotein designs for other viruses, it incorporates a scaffold to enforce assembly in the absence of the transmembrane domains, along with a furin cleavage site to permit native-like heterodimerization. This sE1E2 was found to assemble into a form closer to its expected size than full-length E1E2. Preservation of native structural elements was confirmed by high-affinity binding to a panel of conformationally specific monoclonal antibodies, including two neutralizing antibodies specific to native E1E2 and to its primary receptor, CD81. Finally, sE1E2 was found to elicit robust neutralizing antibodies in vivo. This designed sE1E2 can both provide insights into the determinants of native E1E2 assembly and serve as a platform for production of E1E2 for future structural and vaccine studies, enabling rational optimization of an E1E2-based antigen.
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Affiliation(s)
- Johnathan D Guest
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Ruixue Wang
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Khadija H Elkholy
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Molecular Biology Department, Genetic Engineering and Biotechnology Division, National Research Centre, Cairo 12622, Egypt
| | - Andrezza Chagas
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Kinlin L Chao
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Thomas E Cleveland
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - Young Chang Kim
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Zhen-Yong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Alexander Marin
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Abdul S Yunus
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Roy A Mariuzza
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Alexander K Andrianov
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Eric A Toth
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305
| | - Brian G Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850;
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
| | - Thomas R Fuerst
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850;
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742
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13
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Ströh LJ, Krey T. HCV Glycoprotein Structure and Implications for B-Cell Vaccine Development. Int J Mol Sci 2020; 21:ijms21186781. [PMID: 32947858 PMCID: PMC7555785 DOI: 10.3390/ijms21186781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/12/2020] [Accepted: 09/14/2020] [Indexed: 02/06/2023] Open
Abstract
Despite the approval of highly efficient direct-acting antivirals in the last decade Hepatitis C virus (HCV) remains a global health burden and the development of a vaccine would constitute an important step towards the control of HCV. The high genetic variability of the viral glycoproteins E1 and E2, which carry the main neutralizing determinants, together with their intrinsic structural flexibility, the high level of glycosylation that shields conserved neutralization epitopes and immune evasion using decoy epitopes renders the design of an efficient vaccine challenging. Recent structural and functional analyses have highlighted the role of the CD81 receptor binding site on E2, which overlaps with those neutralization epitopes within E2 that have been structurally characterized to date. This CD81 binding site consists of three distinct segments including “epitope I”, “epitope II” and the “CD81 binding loop”. In this review we summarize the structural features of the HCV glycoproteins that have been derived from X-ray structures of neutralizing and non-neutralizing antibody fragments complexed with either recombinant E2 or epitope-derived linear peptides. We focus on the current understanding how neutralizing antibodies interact with their cognate antigen, the structural features of the respective neutralization epitopes targeted by nAbs and discuss the implications for informed vaccine design.
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Affiliation(s)
- Luisa J. Ströh
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany;
| | - Thomas Krey
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany;
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, 23562 Luebeck, Germany
- German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 30625 Hannover, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Luebeck-Borstel-Riems, 23562 Luebeck, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, 30625 Hannover, Germany
- Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany
- Correspondence: ; Tel.: +49-(0)451–3101-3101
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14
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Hepatitis C virus vaccine design: focus on the humoral immune response. J Biomed Sci 2020; 27:78. [PMID: 32631318 PMCID: PMC7338099 DOI: 10.1186/s12929-020-00669-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 06/26/2020] [Indexed: 02/06/2023] Open
Abstract
Despite the recent development of safe and highly effective direct-acting antivirals, hepatitis C virus (HCV) infection remains a significant health problem. In 2016, the World Health Organization set out to reduce the rate of new HCV infections by 90% by 2030. Still, global control of the virus does not seem to be achievable in the absence of an effective vaccine. Current approaches to the development of a vaccine against HCV include the production of recombinant proteins, synthetic peptides, DNA vaccines, virus-like particles, and viral vectors expressing various antigens. In this review, we focus on the development of vaccines targeting the humoral immune response against HCV based on the cumulative evidence supporting the important role of neutralizing antibodies in protection against HCV infection. The main targets of HCV-specific neutralizing antibodies are the glycoproteins E1 and E2. Recent advances in the knowledge of HCV glycoprotein structure and their epitopes, as well as the possibility of getting detailed information on the human antibody repertoire generated by the infection, will allow rational structure-based antigen design to target specific germline antibodies. Although obtaining a vaccine capable of inducing sterilizing immunity will be a difficult task, a vaccine that prevents chronic hepatitis C infections, a more realistic goal in the short term, would have a considerable health impact.
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15
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Czarnota A, Offersgaard A, Pihl AF, Prentoe J, Bukh J, Gottwein JM, Bieńkowska-Szewczyk K, Grzyb K. Specific Antibodies Induced by Immunization with Hepatitis B Virus-Like Particles Carrying Hepatitis C Virus Envelope Glycoprotein 2 Epitopes Show Differential Neutralization Efficiency. Vaccines (Basel) 2020; 8:vaccines8020294. [PMID: 32532076 PMCID: PMC7350033 DOI: 10.3390/vaccines8020294] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 05/30/2020] [Accepted: 06/06/2020] [Indexed: 12/12/2022] Open
Abstract
Hepatitis C virus (HCV) infection with associated chronic liver diseases is a major health problem worldwide. Here, we designed hepatitis B virus (HBV) small surface antigen (sHBsAg) virus-like particles (VLPs) presenting different epitopes derived from the HCV E2 glycoprotein (residues 412-425, 434-446, 502-520, and 523-535 of isolate H77C). Epitopes were selected based on their amino acid sequence conservation and were previously reported as targets of HCV neutralizing antibodies. Chimeric VLPs obtained in the Leishmania tarentolae expression system, in combination with the adjuvant Addavax, were used to immunize mice. Although all VLPs induced strong humoral responses, only antibodies directed against HCV 412-425 and 523-535 epitopes were able to react with the native E1E2 glycoprotein complexes of different HCV genotypes in ELISA. Neutralization assays against genotype 1-6 cell culture infectious HCV (HCVcc), revealed that only VLPs carrying the 412-425 epitope induced efficient HCV cross-neutralizing antibodies, but with isolate specific variations in efficacy that could not necessarily be explained by differences in epitope sequences. In contrast, antibodies targeting 434-446, 502-520, and 523-535 epitopes were not neutralizing HCVcc, highlighting the importance of conformational antibodies for efficient virus neutralization. Thus, 412-425 remains the most promising linear E2 epitope for further bivalent, rationally designed vaccine research.
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Affiliation(s)
- Anna Czarnota
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, 80-309 Gdańsk, Poland; (A.C.); (K.B.-S.)
| | - Anna Offersgaard
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark; (A.O.); (A.F.P.); (J.P.); (J.B.); (J.M.G.)
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Anne Finne Pihl
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark; (A.O.); (A.F.P.); (J.P.); (J.B.); (J.M.G.)
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark; (A.O.); (A.F.P.); (J.P.); (J.B.); (J.M.G.)
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark; (A.O.); (A.F.P.); (J.P.); (J.B.); (J.M.G.)
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Judith Margarete Gottwein
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark; (A.O.); (A.F.P.); (J.P.); (J.B.); (J.M.G.)
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Krystyna Bieńkowska-Szewczyk
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, 80-309 Gdańsk, Poland; (A.C.); (K.B.-S.)
| | - Katarzyna Grzyb
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology, University of Gdańsk, 80-309 Gdańsk, Poland; (A.C.); (K.B.-S.)
- Correspondence:
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16
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Substitution of the CD81 Binding Site and β-Sandwich Area in E2 of HCV in Cambodia. Viruses 2020; 12:v12050551. [PMID: 32429467 PMCID: PMC7290788 DOI: 10.3390/v12050551] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 05/13/2020] [Accepted: 05/14/2020] [Indexed: 12/14/2022] Open
Abstract
The high genetic variability of hepatitis C virus (HCV) is the main obstacle to developing a vaccine. E2 has attracted attention for vaccine development because targeting this protein could potentially overcome issues related to the genetic diversity of HCV. In this study, we analyzed HCV genes in the general population of Cambodia and investigated the E2 locus as a candidate for vaccine development. HCV sero-epidemiological surveys were conducted between the period 2010 and 2014, with an HCV RNA–positive rate of 1.3% (11/868). Follow-up blood samples were collected from four anti-HCV– and HCV RNA– positive patients (genotype 1b: 2 cases, 6e: 1 case, 6r: 1 case) after 4.12 years. Analysis of HCV full-length nucleotide sequences in paired specimens revealed that the mutation rates of HCV genotypes 1b and 6e/6r were 1.61–2.03 × 10−3 and 2.52–2.74 × 10−3 substitutions/site/year, respectively. Non-synonymous substitutions were detected in HVR1, the front layer of the CD81 binding site, and the β-sandwich, but not in the N-terminal region or adjacent to the CD81 binding site. Therefore, we conclude that the CD81 binding site is a promising locus for HCV vaccine development.
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17
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Stejskal L, Lees WD, Moss DS, Palor M, Bingham RJ, Shepherd AJ, Grove J. Flexibility and intrinsic disorder are conserved features of hepatitis C virus E2 glycoprotein. PLoS Comput Biol 2020; 16:e1007710. [PMID: 32109245 PMCID: PMC7065822 DOI: 10.1371/journal.pcbi.1007710] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 03/11/2020] [Accepted: 02/04/2020] [Indexed: 12/15/2022] Open
Abstract
The glycoproteins of hepatitis C virus, E1E2, are unlike any other viral fusion machinery yet described, and are the current focus of immunogen design in HCV vaccine development; thus, making E1E2 both scientifically and medically important. We used pre-existing, but fragmentary, structures to model a complete ectodomain of the major glycoprotein E2 from three strains of HCV. We then performed molecular dynamic simulations to explore the conformational landscape of E2, revealing a number of important features. Despite high sequence divergence, and subtle differences in the models, E2 from different strains behave similarly, possessing a stable core flanked by highly flexible regions, some of which perform essential functions such as receptor binding. Comparison with sequence data suggest that this consistent behaviour is conferred by a network of conserved residues that act as hinge and anchor points throughout E2. The variable regions (HVR-1, HVR-2 and VR-3) exhibit particularly high flexibility, and bioinformatic analysis suggests that HVR-1 is a putative intrinsically disordered protein region. Dynamic cross-correlation analyses demonstrate intramolecular communication and suggest that specific regions, such as HVR-1, can exert influence throughout E2. To support our computational approach we performed small-angle X-ray scattering with purified E2 ectodomain; this data was consistent with our MD experiments, suggesting a compact globular core with peripheral flexible regions. This work captures the dynamic behaviour of E2 and has direct relevance to the interaction of HCV with cell-surface receptors and neutralising antibodies.
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Affiliation(s)
- Lenka Stejskal
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, United Kingdom
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - William D. Lees
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - David S. Moss
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - Machaela Palor
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Richard J. Bingham
- Department of Biological Sciences, University of Huddersfield, Huddersfield, United Kingdom
| | - Adrian J. Shepherd
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - Joe Grove
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, United Kingdom
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18
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Meuleman TJ, Cowton VM, Patel AH, Liskamp RM. Improving the aqueous solubility of HCV-E2 glycoprotein epitope mimics by cyclization using POLAR hinges. J Pept Sci 2020; 26:e3222. [PMID: 31984607 PMCID: PMC7050536 DOI: 10.1002/psc.3222] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/05/2019] [Accepted: 09/09/2019] [Indexed: 12/20/2022]
Abstract
In this research we describe the improvement of the water-solubility of cyclic epitope mimics based on the HCV E2 glycoprotein by incorporation of suitable polar hinges. The poor solubility of epitope mimics based on peptide sequences in the envelope (E2) protein hampered their synthesis and purification and made it very difficult to prepare the molecular constructs for evaluation of their bioactivity. Since changes in the amino acid composition are hardly possible in these epitope mimics in order to increase water-solubility, a polar cyclization hinge may offer a remedy leading to a significant increase of polarity and therefore water solubility. These polar hinges were applied in the synthesis of better water-soluble HCV-E2 epitopes. An azide functionality in the polar hinges allowed attachment of a tetraethylene glycol linker by Cu-catalyzed azide-alkyne cyclo-addition (CuAAC) for a convenient conjugation to ELISA plates in order to evaluate the bio-activity of the epitope mimics. The immunoassays showed that the use of more polar cyclization hinges still supported anti-HCV antibody recognition and did not negatively influence their binding. This significantly increased solubility induced by polar hinges should therefore allow for the molecular construction and ultimate evaluation of synthetic vaccine molecules.
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Affiliation(s)
- Theodorus J. Meuleman
- School of Chemistry, University of GlasgowJoseph Black Building, University AvenueGlasgowG12 8QQUK
| | - Vanessa M. Cowton
- MRC‐University of Glasgow Centre for Virus ResearchGarscube Campus, Sir Michael Stoker Building, 464 Bearsden RoadGlasgowG61 1QHUK
| | - Arvind H. Patel
- MRC‐University of Glasgow Centre for Virus ResearchGarscube Campus, Sir Michael Stoker Building, 464 Bearsden RoadGlasgowG61 1QHUK
| | - Rob M.J. Liskamp
- School of Chemistry, University of GlasgowJoseph Black Building, University AvenueGlasgowG12 8QQUK
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19
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Zhu F, Wang Y, Xu Z, Qu H, Zhang H, Niu L, Xue H, Jing D, He H. Novel adeno‑associated virus‑based genetic vaccines encoding hepatitis C virus E2 glycoprotein elicit humoral immune responses in mice. Mol Med Rep 2018; 19:1016-1023. [PMID: 30569131 PMCID: PMC6323296 DOI: 10.3892/mmr.2018.9739] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 11/20/2018] [Indexed: 12/15/2022] Open
Abstract
Hepatitis C virus (HCV) infection remains a major public health issue despite the introduction of several direct-acting antiviral agents (DAAs), with some 185 million individuals infected with HCV worldwide. There is an urgent need for an effective prophylactic HCV vaccine. In the present study, we constructed genetic vaccines based on novel recombinant adeno-associated viral (rAAV) vectors (AAV2/8 or AAV2/rh32.33) that express the envelope glycoprotein E2 from the HCV genotype 1b. Expression of HCV E2 protein in 293 cells was confirmed by western blot analysis. rAAV2/8.HCV E2 vaccine or rAAV2/rh32.33.HCV E2 vaccine was intramuscularly injected into C57BL/6 mice. HCV E2-specific antigen was produced, and long-lasting specific antibody responses remained detectable XVI weeks following immunization. In addition, the rAAV2/rh32.33 vaccine induced higher antigen-specific antibody levels than the rAAV2/8 vaccine or AAV plasmid. Moreover, both AAV vaccines induced neutralizing antibodies against HCV genotypes 1a and 1b. Finally, it is worth mentioning that neutralizing antibody levels directed against AAV2/rh32.33 were lower than those against AAV2/8 in both mouse and human serum. These results demonstrate that AAV vectors, especially the AAVrh32.33, have particularly favorable immunogenicity for development into an effective HCV vaccine.
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Affiliation(s)
- Fengqin Zhu
- Department of Gastroenterology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Yibo Wang
- Department of Gastroenterology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Zhen Xu
- Department of Gastroenterology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Haiyang Qu
- Department of Gastroenterology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Hairong Zhang
- Department of Gastroenterology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Lingling Niu
- Department of Gastroenterology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Honglu Xue
- Department of Gastroenterology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Dehuai Jing
- Department of Gastroenterology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Heng He
- Department of Gastroenterology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong 272000, P.R. China
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20
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Tarr AW, Backx M, Hamed MR, Urbanowicz RA, McClure CP, Brown RJP, Ball JK. Immunization with a synthetic consensus hepatitis C virus E2 glycoprotein ectodomain elicits virus-neutralizing antibodies. Antiviral Res 2018; 160:25-37. [PMID: 30217650 DOI: 10.1016/j.antiviral.2018.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 09/06/2018] [Accepted: 09/10/2018] [Indexed: 01/06/2023]
Abstract
Global eradication of hepatitis C virus (HCV) infection will require an efficacious vaccine capable of eliciting protective immunity against genetically diverse HCV strains. Natural spontaneous resolution of HCV infection is associated with production of broadly-neutralizing antibodies targeting the HCV glycoproteins E1 and E2. As such, production of cross-neutralizing antibodies is an important endpoint for experimental vaccine trials. Varying success generating cross-neutralizing antibodies has been achieved with immunogens derived from naturally-occurring HCV strains. In this study the challenge of minimising the genetic diversity between the vaccine strain and circulating HCV isolates was addressed. Two novel synthetic E2 glycoprotein immunogens (NotC1 and NotC2) were derived from consensus nucleotide sequences deduced from samples of circulating genotype 1 HCV strains. These two synthetic sequences differed in their relative positions in the overall genotype 1a/1b phylogeny. Expression of these constructs in Drosophila melanogaster S2 cells resulted in high yields of correctly-folded, monomeric E2 protein, which were recognised by broadly neutralizing monoclonal antibodies. Immunization of guinea pigs with either of these consensus immunogens, or a comparable protein representing a circulating genotype 1a strain resulted in high titres of cross-reactive anti-E2 antibodies. All immunogens generated antibodies capable of neutralizing the H77 strain, but NotC1 elicited antibodies that more potently neutralized virus entry. These vaccine-induced antibodies neutralized some viruses representing genotype 1, but not strains representing genotype 2 or genotype 3. Thus, while this approach to vaccine design resulted in correctly folded, immunogenic protein, cross-neutralizing epitopes were not preferentially targeted by the host immune response generated by this immunogen. Greater immunofocussing of vaccines to common epitopes is necessary to successfully elicit broadly neutralizing antibodies.
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Affiliation(s)
- Alexander W Tarr
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - Matthijs Backx
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - Mohamed R Hamed
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK; Medical Microbiology and Immunology Department, Faculty of Medicine, Mansoura University, Egypt
| | - Richard A Urbanowicz
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - C Patrick McClure
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - Richard J P Brown
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - Jonathan K Ball
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK.
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21
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Yost SA, Wang Y, Marcotrigiano J. Hepatitis C Virus Envelope Glycoproteins: A Balancing Act of Order and Disorder. Front Immunol 2018; 9:1917. [PMID: 30197646 PMCID: PMC6117417 DOI: 10.3389/fimmu.2018.01917] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 08/02/2018] [Indexed: 12/16/2022] Open
Abstract
Chronic hepatitis C virus infection often leads to liver cirrhosis and primary liver cancer. In 2015, an estimated 71 million people were living with chronic HCV. Although infection rates have decreased in many parts of the world over the last several decades, incidence of HCV infection doubled between 2010 and 2014 in the United States mainly due to increases in intravenous drug use. The approval of direct acting antiviral treatments is a necessary component in the elimination of HCV, but inherent barriers to treatment (e.g., cost, lack of access to healthcare, adherence to treatment, resistance, etc.) prevent dramatic improvements in infection rates. An effective HCV vaccine would significantly slow the spread of the disease. Difficulties in the development of an HCV culture model system and expression of properly folded- and natively modified-HCV envelope glycoproteins E1 and E2 have hindered vaccine development efforts. The recent structural and biophysical studies of these proteins have demonstrated that the binding sites for the cellular receptor CD-81 and neutralizing antibodies are highly flexible in nature, which complicate vaccine design. Furthermore, the interactions between E1 and E2 throughout HCV infection is poorly understood, and structural flexibility may play a role in shielding antigenic epitopes during infection. Here we discuss the structural complexities of HCV E1 and E2.
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Affiliation(s)
- Samantha A Yost
- Department of Chemistry and Chemical Biology, Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ, United States
| | - Yuanyuan Wang
- Department of Chemistry and Chemical Biology, Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ, United States.,Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Joseph Marcotrigiano
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
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22
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Shoukry NH. Hepatitis C Vaccines, Antibodies, and T Cells. Front Immunol 2018; 9:1480. [PMID: 30002657 PMCID: PMC6031729 DOI: 10.3389/fimmu.2018.01480] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 06/14/2018] [Indexed: 12/22/2022] Open
Abstract
The development of vaccines that protect against persistent hepatitis C virus (HCV) infection remain a public health priority. The broad use of highly effective direct-acting antivirals (DAAs) is unlikely to achieve HCV elimination without vaccines that can limit viral transmission. Two vaccines targeting either the antibody or the T cell response are currently in preclinical or clinical trials. Next-generation vaccines will likely involve a combination of these two strategies. This review summarizes the state of knowledge about the immune protective role of HCV-specific antibodies and T cells and the current vaccine strategies. In addition, it discusses the potential efficacy of vaccination in DAA-cured individuals. Finally, it summarizes the challenges to vaccine development and the collaborative efforts required to overcome them.
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Affiliation(s)
- Naglaa H Shoukry
- Centre de Recherche du Centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, QC, Canada.,Département de médecine, Faculté de médecine, Université de Montréal, Montréal, QC, Canada
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23
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Ströh LJ, Nagarathinam K, Krey T. Conformational Flexibility in the CD81-Binding Site of the Hepatitis C Virus Glycoprotein E2. Front Immunol 2018; 9:1396. [PMID: 29967619 PMCID: PMC6015841 DOI: 10.3389/fimmu.2018.01396] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 06/05/2018] [Indexed: 01/15/2023] Open
Abstract
Numerous antibodies have been described that potently neutralize a broad range of hepatitis C virus (HCV) isolates and the majority of these antibodies target the binding site for the cellular receptor CD81 within the major HCV glycoprotein E2. A detailed understanding of the major antigenic determinants is crucial for the design of an efficient vaccine that elicits high levels of such antibodies. In the past 6 years, structural studies have shed additional light on the way the host’s humoral immune system recognizes neutralization epitopes within the HCV glycoproteins. One of the most striking findings from these studies is that the same segments of the E2 polypeptide chain induce antibodies targeting distinct antigen conformations. This was demonstrated by several crystal structures of identical polypeptide segments bound to different antibodies, highlighting an unanticipated intrinsic structural flexibility that allows binding of antibodies with distinct paratope shapes following an “induced-fit” mechanism. This unprecedented flexibility extends to the entire binding site for the cellular receptor CD81, underlining the importance of dynamic analyses to understand (1) the interplay between HCV and the humoral immune system and (2) the relevance of this structural flexibility for virus entry. This review summarizes the current understanding how neutralizing antibodies target structurally flexible epitopes. We focus on differences and common features of the reported structures and discuss the implications of the observed structural flexibility for the viral replication cycle, the full scope of the interplay between the virus and the host immune system and—most importantly—informed vaccine design.
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Affiliation(s)
- Luisa J Ströh
- Institute of Virology, Hannover Medical School, Hannover, Germany
| | | | - Thomas Krey
- Institute of Virology, Hannover Medical School, Hannover, Germany
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24
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Tzarum N, Wilson IA, Law M. The Neutralizing Face of Hepatitis C Virus E2 Envelope Glycoprotein. Front Immunol 2018; 9:1315. [PMID: 29951061 PMCID: PMC6008530 DOI: 10.3389/fimmu.2018.01315] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/28/2018] [Indexed: 12/22/2022] Open
Abstract
The high genetic variability of hepatitis C virus, together with the high level of glycosylation on the viral envelope proteins shielding potential neutralizing epitopes, pose a difficult challenge for vaccine development. An effective hepatitis C virus (HCV) vaccine must target conserved epitopes and the HCV E2 glycoprotein is the main target for such neutralizing antibodies (NAbs). Recent structural investigations highlight the presence of a highly conserved and accessible surface on E2 that is devoid of N-linked glycans and known as the E2 neutralizing face. This face is defined as a hydrophobic surface comprising the front layer (FL) and the CD81 binding loop (CD81bl) that overlap with the CD81 receptor binding site on E2. The neutralizing face consists of highly conserved residues for recognition by cross-NAbs, yet it appears to be high conformationally flexible, thereby presenting a moving target for NAbs. Three main overlapping neutralizing sites have been identified in the neutralizing face: antigenic site 412 (AS412), antigenic site 434 (AS434), and antigenic region 3 (AR3). Here, we review the structural analyses of these neutralizing sites, either as recombinant E2 or epitope-derived linear peptides in complex with bNAbs, to understand the functional and preferred conformations for neutralization, and for viral escape. Collectively, these studies provide a foundation and molecular templates to facilitate structure-based approaches for HCV vaccine development.
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Affiliation(s)
- Netanel Tzarum
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, United States
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, United States.,Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, United States
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, United States
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25
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Guest JD, Pierce BG. Computational Modeling of Hepatitis C Virus Envelope Glycoprotein Structure and Recognition. Front Immunol 2018; 9:1117. [PMID: 29892287 PMCID: PMC5985375 DOI: 10.3389/fimmu.2018.01117] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/03/2018] [Indexed: 12/16/2022] Open
Abstract
Hepatitis C virus (HCV) is a major global health concern, and though therapeutic options have improved, no vaccine is available despite decades of research. As HCV can rapidly mutate to evade the immune response, an effective HCV vaccine must rely on identification and characterization of sites critical for broad immune protection and viral neutralization. This knowledge depends on structural and mechanistic insights of the E1 and E2 envelope glycoproteins, which assemble as a heterodimer on the surface of the virion, engage coreceptors during host cell entry, and are the primary targets of antibodies. Due to the challenges in determining experimental structures, structural information on E1 and E2 and their interaction is relatively limited, providing opportunities to model the structures, interactions, and dynamics of these proteins. This review highlights efforts to model the E2 glycoprotein structure, the assembly of the functional E1E2 heterodimer, the structure and binding of human coreceptors, and recognition by key neutralizing antibodies. We also discuss a comparison of recently described models of full E1E2 heterodimer structures, a simulation of the dynamics of key epitope sites, and modeling glycosylation. These modeling efforts provide useful mechanistic hypotheses for further experimental studies of HCV envelope assembly, recognition, and viral fitness, and underscore the benefit of combining experimental and computational modeling approaches to reveal new insights. Additionally, computational design approaches have produced promising candidates for epitope-based vaccine immunogens that specifically target key epitopes, providing a possible avenue to optimize HCV vaccines versus using native glycoproteins. Advancing knowledge of HCV envelope structure and immune recognition is highly applicable toward the development of an effective vaccine for HCV and can provide lessons and insights relevant to modeling and characterizing other viruses.
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Affiliation(s)
- Johnathan D Guest
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, United States.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
| | - Brian G Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, United States.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
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26
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Balasco N, Barone D, Iaccarino E, Sandomenico A, De Simone A, Ruvo M, Vitagliano L. Intrinsic structural versatility of the highly conserved 412-423 epitope of the Hepatitis C Virus E2 protein. Int J Biol Macromol 2018; 116:620-632. [PMID: 29758309 DOI: 10.1016/j.ijbiomac.2018.05.055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/09/2018] [Accepted: 05/10/2018] [Indexed: 12/14/2022]
Abstract
HCV infection is a major threaten for human health as it affects hundreds of million people worldwide. Here we investigated the conformational properties of the 412-423 fragment of the envelope E2 protein, one of the most immunogenic regions of the virus proteome whose characterization may provide interesting insights for anti-HCV vaccine development. The spectroscopic characterization of the polypeptide unravels its unexpected tendency to form amyloid-like aggregates. When kept in monomeric state, it shows a limited tendency to adopt regular secondary structure. Enhanced molecular dynamics simulations, starting from four distinct conformational states, highlight its structural versatility. Interestingly, all multiform conformational states of the polypeptide detected in crystallographic complexes with antibodies are present in the structural ensemble of all simulations. This observation corroborates the idea that known antibodies recognize this region through a conformational selection mechanism. Accordingly, the design of effective anti-HCV vaccines should consider the intrinsic flexibility of this region. The structural versatility of the 412-423 region is particularly puzzling if its remarkable sequence conservation is considered. It is likely that flexibility and sequence conservation are important features that endow this epitope with the ability to accomplish distinct functions such as immunity escape and interaction with host receptors.
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Affiliation(s)
- Nicole Balasco
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy.
| | - Daniela Barone
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy; Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Caserta 81100, Italy
| | - Emanuela Iaccarino
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy; Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Caserta 81100, Italy
| | | | - Alfonso De Simone
- Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Menotti Ruvo
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy
| | - Luigi Vitagliano
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy.
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27
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Krapchev VB, Rychłowska M, Chmielewska A, Zimmer K, Patel AH, Bieńkowska-Szewczyk K. Recombinant Flag-tagged E1E2 glycoproteins from three hepatitis C virus genotypes are biologically functional and elicit cross-reactive neutralizing antibodies in mice. Virology 2018; 519:33-41. [PMID: 29631174 PMCID: PMC5998380 DOI: 10.1016/j.virol.2018.03.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 03/28/2018] [Accepted: 03/29/2018] [Indexed: 01/13/2023]
Abstract
Hepatitis C virus (HCV) is a globally disseminated human pathogen for which no vaccine is currently available. HCV is highly diverse genetically and can be classified into 7 genotypes and multiple sub-types. Due to this antigenic variation, the induction of cross-reactive and at the same time neutralizing antibodies is a challenge in vaccine production. Here we report the analysis of immunogenicity of recombinant HCV envelope glycoproteins from genotypes 1a, 1b and 2a, with a Flag tag inserted in the hypervariable region 1 of E2. This modification did not affect protein expression or conformation or its capacity to bind the crucial virus entry factor, CD81. Importantly, in immunogenicity studies on mice, the purified E2-Flag mutants elicited high-titer, cross-reactive antibodies that were able to neutralize HCV infectious particles from two genotypes tested (1a and 2a). These findings indicate that E1E2-Flag envelope glycoproteins could be important immunogen candidates for vaccine aiming to induce broad HCV-neutralizing responses.
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Affiliation(s)
- Vasil B Krapchev
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdansk, 58 Abrahama str., 80-307 Gdansk, Poland
| | - Malgorzata Rychłowska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdansk, 58 Abrahama str., 80-307 Gdansk, Poland
| | - Alicja Chmielewska
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdansk, 58 Abrahama str., 80-307 Gdansk, Poland
| | - Karolina Zimmer
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdansk, 58 Abrahama str., 80-307 Gdansk, Poland
| | - Arvind H Patel
- MRC-University of Glasgow Centre for Virus Research, Sir Michael Stoker Building, Garscube Campus, 464 Bearsden Road, Glasgow G61 1QH, Scotland (UK)
| | - Krystyna Bieńkowska-Szewczyk
- Laboratory of Virus Molecular Biology, Intercollegiate Faculty of Biotechnology of UG and MUG, University of Gdansk, 58 Abrahama str., 80-307 Gdansk, Poland.
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28
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Fuerst TR, Pierce BG, Keck ZY, Foung SKH. Designing a B Cell-Based Vaccine against a Highly Variable Hepatitis C Virus. Front Microbiol 2018; 8:2692. [PMID: 29379486 PMCID: PMC5775222 DOI: 10.3389/fmicb.2017.02692] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/26/2017] [Indexed: 02/06/2023] Open
Abstract
The ability to use structure-based design and engineering to control the molecular shape and reactivity of an immunogen to induce protective responses shows great promise, along with corresponding advancements in vaccine testing and evaluation systems. We describe in this review new paradigms for the development of a B cell-based HCV vaccine. Advances in test systems to measure in vitro and in vivo antibody-mediated virus neutralization include retroviral pseudotype particles expressing HCV E1E2 glycoproteins (HCVpp), infectious cell culture-derived HCV virions (HCVcc), and surrogate animal models mimicking acute HCV infection. Their applications have established the role of broadly neutralizing antibodies to control HCV infection. However, the virus has immunogenic regions in the viral envelope glycoproteins that are associated with viral escape or non-neutralizing antibodies. These regions serve as immunologic decoys that divert the antibody response from less prominent conserved regions mediating virus neutralization. This review outlines the immunogenic regions on E2, which are roughly segregated into the hypervariable region 1 (HVR1), and five clusters of overlapping epitopes designated as antigenic domains A-E. Understanding the molecular architecture of conserved neutralizing epitopes within these antigenic domains, and how other antigenic regions or decoys deflect the immune response from these conserved regions will provide a roadmap for the rational design of an HCV vaccine.
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Affiliation(s)
- Thomas R Fuerst
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, United States.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
| | - Brian G Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, United States.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
| | - Zhen-Yong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, United States
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, United States
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29
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Synergistic anti-HCV broadly neutralizing human monoclonal antibodies with independent mechanisms. Proc Natl Acad Sci U S A 2017; 115:E82-E91. [PMID: 29255018 DOI: 10.1073/pnas.1718441115] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
There is an urgent need for a vaccine to combat the hepatitis C virus (HCV) pandemic, and induction of broadly neutralizing monoclonal antibodies (bNAbs) against HCV is a major goal of vaccine development. Even within HCV genotype 1, no single bNAb effectively neutralizes all viral strains, so induction of multiple neutralizing monoclonal antibodies (NAbs) targeting distinct epitopes may be necessary for protective immunity. Therefore, identification of optimal NAb combinations and characterization of NAb interactions can guide vaccine development. We analyzed neutralization profiles of 12 human NAbs across diverse HCV strains, assigning the NAbs to two functionally distinct clusters. We then measured neutralizing breadth of 35 NAb combinations against genotype 1 isolates, with each combination including one NAb from each neutralization cluster. Many NAbs displayed complementary neutralizing breadth, forming combinations with greater neutralization across diverse strains than any individual bNAb. Remarkably, one of the most broadly neutralizing combinations of two NAbs, designated HEPC74/HEPC98, also displayed enhanced potency, with interactions matching the Bliss independence model, suggesting that these NAbs inhibit HCV infection through independent mechanisms. Subsequent experiments showed that HEPC74 primarily blocks HCV envelope protein binding to CD81, while HEPC98 primarily blocks binding to scavenger receptor B1 and heparan sulfate. Together, these data identify a critical vulnerability resulting from the reliance of HCV on multiple cell surface receptors, suggesting that vaccine induction of multiple NAbs with distinct neutralization profiles is likely to enhance the breadth and potency of the humoral immune response against HCV.
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