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Pierce BG, Felbinger N, Metcalf M, Toth EA, Ofek G, Fuerst TR. Hepatitis C Virus E1E2 Structure, Diversity, and Implications for Vaccine Development. Viruses 2024; 16:803. [PMID: 38793684 PMCID: PMC11125608 DOI: 10.3390/v16050803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/02/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024] Open
Abstract
Hepatitis C virus (HCV) is a major medical health burden and the leading cause of chronic liver disease and cancer worldwide. More than 58 million people are chronically infected with HCV, with 1.5 million new infections occurring each year. An effective HCV vaccine is a major public health and medical need as recognized by the World Health Organization. However, due to the high variability of the virus and its ability to escape the immune response, HCV rapidly accumulates mutations, making vaccine development a formidable challenge. An effective vaccine must elicit broadly neutralizing antibodies (bnAbs) in a consistent fashion. After decades of studies from basic research through clinical development, the antigen of choice is considered the E1E2 envelope glycoprotein due to conserved, broadly neutralizing antigenic domains located in the constituent subunits of E1, E2, and the E1E2 heterodimeric complex itself. The challenge has been elicitation of robust humoral and cellular responses leading to broad virus neutralization due to the relatively low immunogenicity of this antigen. In view of this challenge, structure-based vaccine design approaches to stabilize key antigenic domains have been hampered due to the lack of E1E2 atomic-level resolution structures to guide them. Another challenge has been the development of a delivery platform in which a multivalent form of the antigen can be presented in order to elicit a more robust anti-HCV immune response. Recent nanoparticle vaccines are gaining prominence in the field due to their ability to facilitate a controlled multivalent presentation and trafficking to lymph nodes, where they can interact with both the cellular and humoral components of the immune system. This review focuses on recent advances in understanding the E1E2 heterodimeric structure to facilitate a rational design approach and the potential for development of a multivalent nanoparticle-based HCV E1E2 vaccine. Both aspects are considered important in the development of an effective HCV vaccine that can effectively address viral diversity and escape.
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Affiliation(s)
- Brian G. Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Nathaniel Felbinger
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Matthew Metcalf
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Eric A. Toth
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
| | - Gilad Ofek
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Thomas R. Fuerst
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
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2
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Capella-Pujol J, de Gast M, Radić L, Zon I, Chumbe A, Koekkoek S, Olijhoek W, Schinkel J, van Gils MJ, Sanders RW, Sliepen K. Signatures of V H1-69-derived hepatitis C virus neutralizing antibody precursors defined by binding to envelope glycoproteins. Nat Commun 2023; 14:4036. [PMID: 37419906 PMCID: PMC10328973 DOI: 10.1038/s41467-023-39690-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 06/23/2023] [Indexed: 07/09/2023] Open
Abstract
An effective preventive vaccine for hepatitis C virus (HCV) remains a major unmet need. Antigenic region 3 (AR3) on the E1E2 envelope glycoprotein complex overlaps with the CD81 receptor binding site and represents an important epitope for broadly neutralizing antibodies (bNAbs) and is therefore important for HCV vaccine design. Most AR3 bNAbs utilize the VH1-69 gene and share structural features that define the AR3C-class of HCV bNAbs. In this work, we identify recombinant HCV glycoproteins based on a permuted E2E1 trimer design that bind to the inferred VH1-69 germline precursors of AR3C-class bNAbs. When presented on nanoparticles, these recombinant E2E1 glycoproteins efficiently activate B cells expressing inferred germline AR3C-class bNAb precursors as B cell receptors. Furthermore, we identify critical signatures in three AR3C-class bNAbs that represent two subclasses of AR3C-class bNAbs that will allow refined protein design. These results provide a framework for germline-targeting vaccine design strategies against HCV.
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Affiliation(s)
- Joan Capella-Pujol
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands
| | - Marlon de Gast
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands
| | - Laura Radić
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands
| | - Ian Zon
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands
| | - Ana Chumbe
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands
| | - Sylvie Koekkoek
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands
| | - Wouter Olijhoek
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands
| | - Janke Schinkel
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands
| | - Marit J van Gils
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands
| | - Rogier W Sanders
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands.
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands.
- Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, NY, 10065, USA.
| | - Kwinten Sliepen
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105, AZ, Amsterdam, Netherlands.
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105, AZ, Amsterdam, Netherlands.
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3
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Metcalf MC, Janus BM, Yin R, Wang R, Guest JD, Pozharski E, Law M, Mariuzza RA, Toth EA, Pierce BG, Fuerst TR, Ofek G. Structure of engineered hepatitis C virus E1E2 ectodomain in complex with neutralizing antibodies. Nat Commun 2023; 14:3980. [PMID: 37407593 PMCID: PMC10322937 DOI: 10.1038/s41467-023-39659-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 06/22/2023] [Indexed: 07/07/2023] Open
Abstract
Hepatitis C virus (HCV) is a major global health burden as the leading causative agent of chronic liver disease and hepatocellular carcinoma. While the main antigenic target for HCV-neutralizing antibodies is the membrane-associated E1E2 surface glycoprotein, the development of effective vaccines has been hindered by complications in the biochemical preparation of soluble E1E2 ectodomains. Here, we present a cryo-EM structure of an engineered, secreted E1E2 ectodomain of genotype 1b in complex with neutralizing antibodies AR4A, HEPC74, and IGH520. Structural characterization of the E1 subunit and C-terminal regions of E2 reveal an overall architecture of E1E2 that concurs with that observed for non-engineered full-length E1E2. Analysis of the AR4A epitope within a region of E2 that bridges between the E2 core and E1 defines the structural basis for its broad neutralization. Our study presents the structure of an E1E2 complex liberated from membrane via a designed scaffold, one that maintains all essential structural features of native E1E2. The study advances the understanding of the E1E2 heterodimer structure, crucial for the rational design of secreted E1E2 antigens in vaccine development.
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Affiliation(s)
- Matthew C Metcalf
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Benjamin M Janus
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Rui Yin
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Ruixue Wang
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Johnathan D Guest
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Edwin Pozharski
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
- Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD, USA
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Roy A Mariuzza
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Eric A Toth
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Brian G Pierce
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Thomas R Fuerst
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Gilad Ofek
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, USA.
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA.
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4
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Zhang Z, Yao F, Lv J, Ding Y, Liu X, Zhang L, Ma Z, Zhou P, Wang Y, Guo H, Pan L. Identification of B-cell epitopes on structural proteins VP1 and VP2 of Senecavirus A and development of a multi-epitope recombinant protein vaccine. Virology 2023; 582:48-56. [PMID: 37023612 DOI: 10.1016/j.virol.2023.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 03/24/2023] [Accepted: 03/27/2023] [Indexed: 04/01/2023]
Abstract
Senecavirus A (SVA) is an important pathogenic cause of vesicular disease in pigs worldwide. In this study, we screened the B-cell epitopes of SVA using a bioinformatics approach combined with an overlapping synthetic polypeptide method. Four dominant B-cell epitopes (at amino acid (aa) positions: 7-26, 48-74, 92-109, and 129-144) from the VP1 protein and five dominant B-cell epitopes (aa: 38-57, 145-160, 154-172, 193-208, 249-284) from the VP2 protein were identified. Multi-epitope genes comprising the identified B-cell epitope domains were synthesized, prokaryotic expressed, and purified, and their immune protection efficacy was evaluated in piglets. Our results showed that the multi-epitope recombinant protein rP2 induced higher neutralizing antibodies and provided 80% protection against homologous SVA challenge. Thus, the B-cell epitope peptides identified in this study are potential candidates for SVA vaccine development, and rP2 may offer safety and efficacy in controlling infectious SVA.
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Affiliation(s)
- Zhongwang Zhang
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China.
| | - Fei Yao
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Jianliang Lv
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Yaozhong Ding
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Xinsheng Liu
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Liping Zhang
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Zhongyuan Ma
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Peng Zhou
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Yonglu Wang
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Huichen Guo
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China
| | - Li Pan
- State Key Laboratory for Animal Disease Control and Prevention, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730046, China.
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5
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Three-Dimensional Reconstruction of the Hepatitis C Virus Envelope Glycoprotein E1E2 Heterodimer by Electron Microscopic Analysis. J Virol 2023; 97:e0178822. [PMID: 36519897 PMCID: PMC9888182 DOI: 10.1128/jvi.01788-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Despite the development of highly effective hepatitis C virus (HCV) treatments, an effective prophylactic vaccine is still lacking. HCV infection is mediated by its envelope glycoproteins, E1 and E2, during the entry process, with E2 binding to cell receptors and E1 mediating endosomal fusion. The structure of E1E2 has only been partially resolved by X-ray crystallography of the core domain of E2 protein (E2c) and its complex with various neutralizing antibodies. Structural understanding of the E1E2 heterodimer in its native form can advance the design of candidates for HCV vaccine development. Here, we analyze the structure of the recombinant HCV E1E2 heterodimer with the aid of well-defined monoclonal anti-E1 and E2 antibodies, as well as a small-molecule chlorcyclizine-diazirine-biotin that can target and cross-link the putative E1 fusion domain. Three-dimensional (3D) models were generated after extensive 2D classification analysis with negative-stain single-particle data sets. We modeled the available crystal structures of the E2c and Fabs into 3D volumes of E1E2-Fab complexes based on the shape and dimension of the domain density. The E1E2 heterodimer exists in monomeric form and consists of a main globular body, presumably depicting the E1 and E2 stem/transmembrane domain, and a protruding structure representing the E2c region, based on anti-E2 Fab binding. At low resolution, a model generated from negative-stain analysis revealed the unique binding and orientation of individual or double Fabs onto the E1 and E2 components of the complex. Cryo-electron microscopy (cryo-EM) of the double Fab complexes resulted in a refined structural model of the E1E2 heterodimer, presented here. IMPORTANCE Recombinant HCV E1E2 heterodimer is being developed as a vaccine candidate. Using electron microscopy, we demonstrated unique features of E1E2 in complex with various neutralizing antibodies and small molecule inhibitors that are important to understanding its antigenicity and induction of immune response.
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Induction of cross-neutralizing antibodies by a permuted hepatitis C virus glycoprotein nanoparticle vaccine candidate. Nat Commun 2022; 13:7271. [PMID: 36434005 PMCID: PMC9700739 DOI: 10.1038/s41467-022-34961-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 11/14/2022] [Indexed: 11/27/2022] Open
Abstract
Hepatitis C virus (HCV) infection affects approximately 58 million people and causes ~300,000 deaths yearly. The only target for HCV neutralizing antibodies is the highly sequence diverse E1E2 glycoprotein. Eliciting broadly neutralizing antibodies that recognize conserved cross-neutralizing epitopes is important for an effective HCV vaccine. However, most recombinant HCV glycoprotein vaccines, which usually include only E2, induce only weak neutralizing antibody responses. Here, we describe recombinant soluble E1E2 immunogens that were generated by permutation of the E1 and E2 subunits. We displayed the E2E1 immunogens on two-component nanoparticles and these nanoparticles induce significantly more potent neutralizing antibody responses than E2. Next, we generated mosaic nanoparticles co-displaying six different E2E1 immunogens. These mosaic E2E1 nanoparticles elicit significantly improved neutralization compared to monovalent E2E1 nanoparticles. These results provide a roadmap for the generation of an HCV vaccine that induces potent and broad neutralization.
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de la Peña AT, Sliepen K, Eshun-Wilson L, Newby ML, Allen JD, Zon I, Koekkoek S, Chumbe A, Crispin M, Schinkel J, Lander GC, Sanders RW, Ward AB. Structure of the hepatitis C virus E1E2 glycoprotein complex. Science 2022; 378:263-269. [PMID: 36264808 PMCID: PMC10512783 DOI: 10.1126/science.abn9884] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Hepatitis C virus (HCV) infection is a leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma in humans and afflicts more than 58 million people worldwide. The HCV envelope E1 and E2 glycoproteins are essential for viral entry and comprise the primary antigenic target for neutralizing antibody responses. The molecular mechanisms of E1E2 assembly, as well as how the E1E2 heterodimer binds broadly neutralizing antibodies, remain elusive. Here, we present the cryo-electron microscopy structure of the membrane-extracted full-length E1E2 heterodimer in complex with three broadly neutralizing antibodies-AR4A, AT1209, and IGH505-at ~3.5-angstrom resolution. We resolve the interface between the E1 and E2 ectodomains and deliver a blueprint for the rational design of vaccine immunogens and antiviral drugs.
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Affiliation(s)
- Alba Torrents de la Peña
- Department of Integrative Structural Biology and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kwinten Sliepen
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105 AZ Amsterdam, Netherlands
| | - Lisa Eshun-Wilson
- Department of Integrative Structural Biology and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Maddy L. Newby
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Joel D. Allen
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Ian Zon
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105 AZ Amsterdam, Netherlands
| | - Sylvie Koekkoek
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105 AZ Amsterdam, Netherlands
| | - Ana Chumbe
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105 AZ Amsterdam, Netherlands
| | - Max Crispin
- School of Biological Sciences, University of Southampton, Southampton SO17 1BJ, UK
| | - Janke Schinkel
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105 AZ Amsterdam, Netherlands
| | - Gabriel C. Lander
- Department of Integrative Structural Biology and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Rogier W. Sanders
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, 1105 AZ Amsterdam, Netherlands
- Amsterdam Institute for Infection and Immunity, Infectious Diseases, 1105 AZ Amsterdam, Netherlands
- Weill Medical College of Cornell University, New York, NY 10065, USA
| | - Andrew B. Ward
- Department of Integrative Structural Biology and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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Pfaff-Kilgore JM, Davidson E, Kadash-Edmondson K, Hernandez M, Rosenberg E, Chambers R, Castelli M, Clementi N, Mancini N, Bailey JR, Crowe JE, Law M, Doranz BJ. Sites of vulnerability in HCV E1E2 identified by comprehensive functional screening. Cell Rep 2022; 39:110859. [PMID: 35613596 PMCID: PMC9281441 DOI: 10.1016/j.celrep.2022.110859] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 12/08/2021] [Accepted: 05/01/2022] [Indexed: 12/15/2022] Open
Abstract
The E1 and E2 envelope proteins of hepatitis C virus (HCV) form a heterodimer that drives virus-host membrane fusion. Here, we analyze the role of each amino acid in E1E2 function, expressing 545 individual alanine mutants of E1E2 in human cells, incorporating them into infectious viral pseudoparticles, and testing them against 37 different monoclonal antibodies (MAbs) to ascertain full-length translation, folding, heterodimer assembly, CD81 binding, viral pseudoparticle incorporation, and infectivity. We propose a model describing the role of each critical residue in E1E2 functionality and use it to examine how MAbs neutralize infection by exploiting functionally critical sites of vulnerability on E1E2. Our results suggest that E1E2 is a surprisingly fragile protein complex where even a single alanine mutation at 92% of positions disrupts its function. The amino-acid-level targets identified are highly conserved and functionally critical and can be exploited for improved therapies and vaccines.
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Affiliation(s)
| | - Edgar Davidson
- Integral Molecular, Inc., 3711 Market St, Philadelphia, PA 19104, USA
| | | | - Mayda Hernandez
- Integral Molecular, Inc., 3711 Market St, Philadelphia, PA 19104, USA
| | - Erin Rosenberg
- Integral Molecular, Inc., 3711 Market St, Philadelphia, PA 19104, USA
| | - Ross Chambers
- Integral Molecular, Inc., 3711 Market St, Philadelphia, PA 19104, USA
| | - Matteo Castelli
- Laboratory of Medical Microbiology and Virology, University Vita-Salute San Raffaele, Milan, Italy
| | - Nicola Clementi
- Laboratory of Medical Microbiology and Virology, University Vita-Salute San Raffaele, Milan, Italy; IRCSS San Raffaele Hospital, Milan, Italy
| | - Nicasio Mancini
- Laboratory of Medical Microbiology and Virology, University Vita-Salute San Raffaele, Milan, Italy; IRCSS San Raffaele Hospital, Milan, Italy
| | - Justin R Bailey
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - James E Crowe
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Benjamin J Doranz
- Integral Molecular, Inc., 3711 Market St, Philadelphia, PA 19104, USA.
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9
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Desombere I, Van Houtte F, Farhoudi A, Verhoye L, Buysschaert C, Gijbels Y, Couvent S, Swinnen W, Van Vlierberghe H, Elewaut A, Magri A, Stamataki Z, Meuleman P, McKeating JA, Leroux-Roels G. A Role for B Cells to Transmit Hepatitis C Virus Infection. Front Immunol 2021; 12:775098. [PMID: 34975862 PMCID: PMC8716873 DOI: 10.3389/fimmu.2021.775098] [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: 09/13/2021] [Accepted: 11/29/2021] [Indexed: 12/02/2022] Open
Abstract
Hepatitis C virus (HCV) is highly variable and transmits through infected blood to establish a chronic liver infection in the majority of patients. Our knowledge on the infectivity of clinical HCV strains is hampered by the lack of in vitro cell culture systems that support efficient viral replication. We and others have reported that HCV can associate with and infect immune cells and may thereby evade host immune surveillance and elimination. To evaluate whether B cells play a role in HCV transmission, we assessed the ability of B cells and sera from recent (<2 years) or chronic (≥ 2 years) HCV patients to infect humanized liver chimeric mice. HCV was transmitted by B cells from chronic infected patients whereas the sera were non-infectious. In contrast, B cells from recently infected patients failed to transmit HCV to the mice, whereas all serum samples were infectious. We observed an association between circulating anti-glycoprotein E1E2 antibodies and B cell HCV transmission. Taken together, our studies provide evidence for HCV transmission by B cells, findings that have clinical implications for prophylactic and therapeutic antibody-based vaccine design.
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Affiliation(s)
| | - Freya Van Houtte
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Ali Farhoudi
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Lieven Verhoye
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | | | - Yvonne Gijbels
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Sibyl Couvent
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | | | - Hans Van Vlierberghe
- Department of Hepatology and Gastroenterology, Ghent University Hospital, Ghent, Belgium
- Laboratory of Hepatology Research, Ghent University, Ghent, Belgium
| | - André Elewaut
- Department of Hepatology and Gastroenterology, Ghent University Hospital, Ghent, Belgium
- Laboratory of Hepatology Research, Ghent University, Ghent, Belgium
| | - Andrea Magri
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Zania Stamataki
- Institute of Immunology and Immunotherapy, Centre for Liver and Gastrointestinal Research, University of Birmingham, Birmingham, United Kingdom
- National Institute for Health Researc (NIHR) Birmingham Liver Biomedical Research Centre, University Hospitals Birmingham National Health Service (NHS) Foundation Trust, Birmingham, United Kingdom
| | - Philip Meuleman
- Department of Diagnostic Sciences, Ghent University, Ghent, Belgium
| | - Jane A McKeating
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
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10
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Incorporation of apolipoprotein E into HBV-HCV subviral envelope particles to improve the hepatitis vaccine strategy. Sci Rep 2021; 11:21856. [PMID: 34750487 PMCID: PMC8575973 DOI: 10.1038/s41598-021-01428-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 10/27/2021] [Indexed: 12/20/2022] Open
Abstract
Hepatitis C is a major threat to public health for which an effective treatment is available, but a prophylactic vaccine is still needed to control this disease. We designed a vaccine based on chimeric HBV-HCV envelope proteins forming subviral particles (SVPs) that induce neutralizing antibodies against HCV in vitro. Here, we aimed to increase the neutralizing potential of those antibodies, by using HBV-HCV SVPs bearing apolipoprotein E (apoE). These particles were produced by cultured stable mammalian cell clones, purified and characterized. We found that apoE was able to interact with both chimeric HBV-HCV (E1-S and E2-S) proteins, and with the wild-type HBV S protein. ApoE was also detected on the surface of purified SVPs and improved the folding of HCV envelope proteins, but its presence lowered the incorporation of E2-S protein. Immunization of New Zealand rabbits resulted in similar anti-S responses for all rabbits, whereas anti-E1/-E2 antibody titers varied according to the presence or absence of apoE. Regarding the neutralizing potential of these anti-E1/-E2 antibodies, it was higher in rabbits immunized with apoE-bearing particles. In conclusion, the association of apoE with HCV envelope proteins may be a good strategy for improving HCV vaccines based on viral envelope proteins.
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11
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Frumento N, Flyak AI, Bailey JR. Mechanisms of HCV resistance to broadly neutralizing antibodies. Curr Opin Virol 2021; 50:23-29. [PMID: 34329953 PMCID: PMC8500940 DOI: 10.1016/j.coviro.2021.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 12/12/2022]
Abstract
Broadly neutralizing antibodies (bNAbs) block infection by genetically diverse hepatitis C virus (HCV) isolates by targeting relatively conserved epitopes on the HCV envelope glycoproteins, E1 and E2. Many amino acid substitutions conferring resistance to these bNAbs have been characterized, identifying multiple mechanisms of bNAb escape. Some resistance substitutions follow the expected mechanism of directly disrupting targeted epitopes. Interestingly, other resistance substitutions fall in E2 domains distant from bNAb-targeted epitopes. These substitutions, which can confer broad resistance to multiple bNAbs, act by less clearly defined mechanisms. Some modulate binding of HCV to cell surface receptors, while others may induce conformational changes in the E2 protein. In this review, we discuss mechanisms of HCV bNAb resistance and implications for HCV vaccine development.
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Affiliation(s)
- Nicole Frumento
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Andrew I Flyak
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Justin R Bailey
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
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12
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Mesalam AA. Hepatitis C Virus Vaccine Development: A Step Forward. J Infect Dis 2021; 223:2014-2016. [PMID: 33038255 DOI: 10.1093/infdis/jiaa644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/05/2020] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ahmed Atef Mesalam
- Department of Therapeutic Chemistry and Centre of Excellence for Advanced Sciences, National Research Centre, Dokki, Cairo, Egypt.,Research Group Immune- and Bio-markers for Infection, Centre of Excellence for Advanced Sciences, National Research Centre, Dokki, Cairo, Egypt
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13
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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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14
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Structure-Based and Rational Design of a Hepatitis C Virus Vaccine. Viruses 2021; 13:v13050837. [PMID: 34063143 PMCID: PMC8148096 DOI: 10.3390/v13050837] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 04/27/2021] [Accepted: 04/30/2021] [Indexed: 12/11/2022] Open
Abstract
A hepatitis C virus (HCV) vaccine is a critical yet unfulfilled step in addressing the global disease burden of HCV. While decades of research have led to numerous clinical and pre-clinical vaccine candidates, these efforts have been hindered by factors including HCV antigenic variability and immune evasion. Structure-based and rational vaccine design approaches have capitalized on insights regarding the immune response to HCV and the structures of antibody-bound envelope glycoproteins. Despite successes with other viruses, designing an immunogen based on HCV glycoproteins that can elicit broadly protective immunity against HCV infection is an ongoing challenge. Here, we describe HCV vaccine design approaches where immunogens were selected and optimized through analysis of available structures, identification of conserved epitopes targeted by neutralizing antibodies, or both. Several designs have elicited immune responses against HCV in vivo, revealing correlates of HCV antigen immunogenicity and breadth of induced responses. Recent studies have elucidated the functional, dynamic and immunological features of key regions of the viral envelope glycoproteins, which can inform next-generation immunogen design efforts. These insights and design strategies represent promising pathways to HCV vaccine development, which can be further informed by successful immunogen designs generated for other viruses.
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15
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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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16
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Velázquez-Moctezuma R, Augestad EH, Castelli M, Holmboe Olesen C, Clementi N, Clementi M, Mancini N, Prentoe J. Mechanisms of Hepatitis C Virus Escape from Vaccine-Relevant Neutralizing Antibodies. Vaccines (Basel) 2021; 9:291. [PMID: 33804732 PMCID: PMC8004074 DOI: 10.3390/vaccines9030291] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 12/15/2022] Open
Abstract
Hepatitis C virus (HCV) is a major causative agent of acute and chronic hepatitis. It is estimated that 400,000 people die every year from chronic HCV infection, mostly from severe liver-related diseases such as cirrhosis and liver cancer. Although HCV was discovered more than 30 years ago, an efficient prophylactic vaccine is still missing. The HCV glycoprotein complex, E1/E2, is the principal target of neutralizing antibodies (NAbs) and, thus, is an attractive antigen for B-cell vaccine design. However, the high genetic variability of the virus necessitates the identification of conserved epitopes. Moreover, the high intrinsic mutational capacity of HCV allows the virus to continually escape broadly NAbs (bNAbs), which is likely to cause issues with vaccine-resistant variants. Several studies have assessed the barrier-to-resistance of vaccine-relevant bNAbs in vivo and in vitro. Interestingly, recent studies have suggested that escape substitutions can confer antibody resistance not only by direct modification of the epitope but indirectly through allosteric effects, which can be grouped based on the breadth of these effects on antibody susceptibility. In this review, we summarize the current understanding of HCV-specific NAbs, with a special focus on vaccine-relevant bNAbs and their targets. We highlight antibody escape studies pointing out the different methodologies and the escape mutations identified thus far. Finally, we analyze the antibody escape mechanisms of envelope protein escape substitutions and polymorphisms according to the most recent evidence in the HCV field. The accumulated knowledge in identifying bNAb epitopes as well as assessing barriers to resistance and elucidating relevant escape mechanisms may prove critical in the successful development of an HCV B-cell vaccine.
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Affiliation(s)
- Rodrigo Velázquez-Moctezuma
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
| | - Elias H. Augestad
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
| | - Matteo Castelli
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Christina Holmboe Olesen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
| | - Nicola Clementi
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Massimo Clementi
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Nicasio Mancini
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
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17
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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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18
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Optimized Hepatitis C Virus (HCV) E2 Glycoproteins and their Immunogenicity in Combination with MVA-HCV. Vaccines (Basel) 2020; 8:vaccines8030440. [PMID: 32764419 PMCID: PMC7563715 DOI: 10.3390/vaccines8030440] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/22/2020] [Accepted: 07/25/2020] [Indexed: 12/20/2022] Open
Abstract
Hepatitis C virus (HCV) represents a major global health challenge and an efficient vaccine is urgently needed. Many HCV vaccination strategies employ recombinant versions of the viral E2 glycoprotein. However, recombinant E2 readily forms disulfide-bonded aggregates that might not be optimally suited for vaccines. Therefore, we have designed an E2 protein in which we strategically changed eight cysteines to alanines (E2.C8A). E2.C8A formed predominantly monomers and virtually no aggregates. Furthermore, E2.C8A also interacted more efficiently with broadly neutralizing antibodies than conventional E2. We used mice to evaluate different prime/boost immunization strategies involving a modified vaccinia virus Ankara (MVA) expressing the nearly full-length genome of HCV (MVA-HCV) in combination with either the E2 aggregates or the E2.C8A monomers. The combined MVA-HCV/E2 aggregates prime/boost strategy markedly enhanced HCV-specific effector memory CD4+ T cell responses and antibody levels compared to MVA-HCV/MVA-HCV. Moreover, the aggregated form of E2 induced higher levels of anti-E2 antibodies in vaccinated mice than E2.C8A monomers. These antibodies were cross-reactive and mainly of the IgG1 isotype. Our findings revealed how two E2 viral proteins that differ in their capacity to form aggregates are able to enhance to different extent the HCV-specific cellular and humoral immune responses, either alone or in combination with MVA-HCV. These combined protocols of MVA-HCV/E2 could serve as a basis for the development of a more effective HCV vaccine.
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19
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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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20
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Olbrich A, Wardemann H, Böhm S, Rother K, Colpitts CC, Wrensch F, Baumert TF, Berg T, Benckert J. Repertoire and Neutralizing Activity of Antibodies Against Hepatitis C Virus E2 Peptide in Patients With Spontaneous Resolution of Hepatitis C. J Infect Dis 2020; 220:1209-1218. [PMID: 31165162 DOI: 10.1093/infdis/jiz274] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Accepted: 06/03/2019] [Indexed: 12/15/2022] Open
Abstract
Neutralizing antibodies can prevent hepatitis C virus (HCV) infection, one of the leading causes of cirrhosis and liver cancer. Here, we characterized the immunoglobulin repertoire of memory B-cell antibodies against a linear epitope in the central front layer of the HCV envelope (E2; amino acids 483-499) in patients who were infected in a single-source outbreak. A reverse transcription polymerase chain reaction-based immunoglobulin gene cloning and recombinant expression approach was used to express monoclonal antibodies from HCV E2 peptide-binding immunoglobulin G-positive memory B cells. We identified highly mutated antibodies with a neutralizing effect in vitro against different genotype isolates sharing similar gene features. Our data confirm the importance of VH1-69 use for neutralizing activity. The data offer a promising basis for vaccine research and the use of anti-E2 antibodies as a means of passive immunization.
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Affiliation(s)
- Anne Olbrich
- Laboratory for Clinical and Experimental Hepatology, Section of Hepatology, Clinic for Gastroenterology and Rheumatology, University Clinic Leipzig, Leipzig, Germany
| | - Hedda Wardemann
- Division of B Cell Immunology, German Cancer Research Center, Heidelberg, Germany
| | - Stephan Böhm
- Laboratory for Clinical and Experimental Hepatology, Section of Hepatology, Clinic for Gastroenterology and Rheumatology, University Clinic Leipzig, Leipzig, Germany.,Max von Pettenkofer Institute, Munich, Germany
| | - Karen Rother
- Laboratory for Clinical and Experimental Hepatology, Section of Hepatology, Clinic for Gastroenterology and Rheumatology, University Clinic Leipzig, Leipzig, Germany
| | - Che C Colpitts
- Inserm U1110, University of Strasbourg, France.,Division of Infection and Immunity, University College London, United Kingdom
| | - Florian Wrensch
- Clinic for Hepatology and Gastroenterology, Charité, CVK, Berlin, Germany
| | - Thomas F Baumert
- Clinic for Hepatology and Gastroenterology, Charité, CVK, Berlin, Germany
| | - Thomas Berg
- Laboratory for Clinical and Experimental Hepatology, Section of Hepatology, Clinic for Gastroenterology and Rheumatology, University Clinic Leipzig, Leipzig, Germany
| | - Julia Benckert
- Laboratory for Clinical and Experimental Hepatology, Section of Hepatology, Clinic for Gastroenterology and Rheumatology, University Clinic Leipzig, Leipzig, Germany.,Inserm U1110, University of Strasbourg, France
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21
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Center RJ, Boo I, Phu L, McGregor J, Poumbourios P, Drummer HE. Enhancing the antigenicity and immunogenicity of monomeric forms of hepatitis C virus E2 for use as a preventive vaccine. J Biol Chem 2020; 295:7179-7192. [PMID: 32299914 PMCID: PMC7247312 DOI: 10.1074/jbc.ra120.013015] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/13/2020] [Indexed: 12/13/2022] Open
Abstract
The E2 glycoprotein of hepatitis C virus (HCV) is the major target of broadly neutralizing antibodies (bNAbs) that are critical for the efficacy of a prophylactic HCV vaccine. We previously showed that a cell culture-derived, disulfide-linked high-molecular-weight (HMW) form of the E2 receptor-binding domain lacking three variable regions, Δ123-HMW, elicits broad neutralizing activity against the seven major genotypes of HCV. A limitation to the use of this antigen is that it is produced only at low yields and does not have a homogeneous composition. Here, we employed a sequential reduction and oxidation strategy to efficiently refold two high-yielding monomeric E2 species, D123 and a disulfide-minimized version (D123A7), into disulfide-linked HMW-like species (Δ123r and Δ123A7r). These proteins exhibited normal reactivity to bNAbs with continuous epitopes on the neutralizing face of E2, but reduced reactivity to conformation-dependent bNAbs and nonneutralizing antibodies (non-NAbs) compared with the corresponding monomeric species. Δ123r and Δ123A7r recapitulated the immunogenic properties of cell culture-derived D123-HMW in guinea pigs. The refolded antigens elicited antibodies that neutralized homologous and heterologous HCV genotypes, blocked the interaction between E2 and its cellular receptor CD81, and targeted the AS412, AS434, and AR3 domains. Of note, antibodies directed to epitopes overlapping with those of non-NAbs were absent. The approach to E2 antigen engineering outlined here provides an avenue for the development of preventive HCV vaccine candidates that induce bNAbs at higher yield and lower cost.
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Affiliation(s)
- Rob J Center
- Burnet Institute, 85 Commercial Road, Melbourne 3004, Australia; Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne 3000, Australia
| | - Irene Boo
- Burnet Institute, 85 Commercial Road, Melbourne 3004, Australia
| | - Lilian Phu
- Burnet Institute, 85 Commercial Road, Melbourne 3004, Australia; Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne 3000, Australia
| | - Joey McGregor
- Burnet Institute, 85 Commercial Road, Melbourne 3004, Australia; Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne 3000, Australia
| | - Pantelis Poumbourios
- Burnet Institute, 85 Commercial Road, Melbourne 3004, Australia; Department of Microbiology, Monash University, Clayton 3056, Australia
| | - Heidi E Drummer
- Burnet Institute, 85 Commercial Road, Melbourne 3004, Australia; Department of Microbiology and Immunology at the Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne 3000, Australia; Department of Microbiology, Monash University, Clayton 3056, Australia.
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22
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He L, Tzarum N, Lin X, Shapero B, Sou C, Mann CJ, Stano A, Zhang L, Nagy K, Giang E, Law M, Wilson IA, Zhu J. Proof of concept for rational design of hepatitis C virus E2 core nanoparticle vaccines. SCIENCE ADVANCES 2020; 6:eaaz6225. [PMID: 32494617 PMCID: PMC7159917 DOI: 10.1126/sciadv.aaz6225] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/22/2020] [Indexed: 05/05/2023]
Abstract
Hepatitis C virus (HCV) envelope glycoproteins E1 and E2 are responsible for cell entry, with E2 being the major target of neutralizing antibodies (NAbs). Here, we present a comprehensive strategy for B cell-based HCV vaccine development through E2 optimization and nanoparticle display. We redesigned variable region 2 in a truncated form (tVR2) on E2 cores derived from genotypes 1a and 6a, resulting in improved stability and antigenicity. Crystal structures of three optimized E2 cores with human cross-genotype NAbs (AR3s) revealed how the modified tVR2 stabilizes E2 without altering key neutralizing epitopes. We then displayed these E2 cores on 24- and 60-meric nanoparticles and achieved substantial yield and purity, as well as enhanced antigenicity. In mice, these nanoparticles elicited more effective NAb responses than soluble E2 cores. Next-generation sequencing (NGS) defined distinct B cell patterns associated with nanoparticle-induced antibody responses, which target the conserved neutralizing epitopes on E2 and cross-neutralize HCV genotypes.
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Affiliation(s)
- Linling He
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Netanel Tzarum
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xiaohe Lin
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Benjamin Shapero
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Cindy Sou
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Colin J Mann
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Armando Stano
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Lei Zhang
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kenna Nagy
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Erick Giang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jiang Zhu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
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23
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Hepatitis C Virus Entry: An Intriguingly Complex and Highly Regulated Process. Int J Mol Sci 2020; 21:ijms21062091. [PMID: 32197477 PMCID: PMC7140000 DOI: 10.3390/ijms21062091] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/15/2020] [Accepted: 03/16/2020] [Indexed: 02/07/2023] Open
Abstract
Hepatitis C virus (HCV) is a major cause of chronic hepatitis and liver disease worldwide. Its tissue and species tropism are largely defined by the viral entry process that is required for subsequent productive viral infection and establishment of chronic infection. This review provides an overview of the viral and host factors involved in HCV entry into hepatocytes, summarizes our understanding of the molecular mechanisms governing this process and highlights the therapeutic potential of host-targeting entry inhibitors.
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24
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Abouelasrar Salama S, Lavie M, De Buck M, Van Damme J, Struyf S. Cytokines and serum amyloid A in the pathogenesis of hepatitis C virus infection. Cytokine Growth Factor Rev 2019; 50:29-42. [PMID: 31718982 DOI: 10.1016/j.cytogfr.2019.10.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 10/17/2019] [Accepted: 10/21/2019] [Indexed: 02/07/2023]
Abstract
Expression of the acute phase protein serum amyloid A (SAA) is dependent on the release of the pro-inflammatory cytokines IL-1, IL-6 and TNF-α during infection and inflammation. Hepatitis C virus (HCV) upregulates SAA-inducing cytokines. In line with this, a segment of chronically infected individuals display increased circulating levels of SAA. SAA has even been proposed to be a potential biomarker to evaluate treatment efficiency and the course of disease. SAA possesses antiviral activity against HCV via direct interaction with the viral particle, but might also divert infectivity through its function as an apolipoprotein. On the other hand, SAA shares inflammatory and angiogenic activity with chemotactic cytokines by activating the G protein-coupled receptor, formyl peptide receptor 2. These latter properties might promote chronic inflammation and hepatic injury. Indeed, up to 80 % of infected individuals develop chronic disease because they cannot completely clear the infection, due to diversion of the immune response. In this review, we summarize the interconnection between SAA and cytokines in the context of HCV infection and highlight the dual role SAA could play in this disease. Nevertheless, more research is needed to establish whether the balance between those opposing activities can be tilted in favor of the host defense.
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Affiliation(s)
- Sara Abouelasrar Salama
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven, 3000, Belgium
| | - Muriel Lavie
- University of Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019, UMR 8204, Centre d'Infection et d'Immunité de Lille, Lille, France
| | - Mieke De Buck
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven, 3000, Belgium
| | - Jo Van Damme
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven, 3000, Belgium
| | - Sofie Struyf
- Laboratory of Molecular Immunology, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, University of Leuven, Leuven, 3000, Belgium.
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25
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Walker MR, Leung P, Eltahla AA, Underwood A, Abayasingam A, Brasher NA, Li H, Wu BR, Maher L, Luciani F, Lloyd AR, Bull RA. Clearance of hepatitis C virus is associated with early and potent but narrowly-directed, Envelope-specific antibodies. Sci Rep 2019; 9:13300. [PMID: 31527718 PMCID: PMC6746763 DOI: 10.1038/s41598-019-49454-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/20/2019] [Indexed: 12/13/2022] Open
Abstract
Hepatitis C virus (HCV) is one of very few viruses that are either naturally cleared, or alternatively persist to cause chronic disease. Viral diversity and escape, as well as host adaptive immune factors, are believed to control the outcome. To date, there is limited understanding of the critical, early host-pathogen interactions. The asymptomatic nature of early HCV infection generally prevents identification of the transmitted/founder (T/F) virus, and thus the study of host responses directed against the autologous T/F strain. In this study, 14 rare subjects identified from very early in infection (4–45 days) with varied disease outcomes (n = 7 clearers) were examined in regard to the timing, breadth, and magnitude of the neutralizing antibody (nAb) response, as well as evolution of the T/F strain. Clearance was associated with earlier onset and more potent nAb responses appearing at a mean of 71 days post-infection (DPI), but these responses were narrowly directed against the autologous T/F virus or closely related variants. In contrast, a delayed onset of nAbs (mean 425 DPI) was observed in chronic progressors that appear to have targeted longitudinal variants rather than the T/F strain. The nAb responses in the chronic progressors mapped to known CD81 binding epitopes, and were associated with rapid emergence of new viral variants with reduced CD81 binding. We propose that the prolonged period of viremia in the absence of nAbs in these subjects was associated with an increase in viral diversity, affording the virus greater options to escape nAb pressure once it emerged. These findings indicate that timing of the nAb response is essential for clearance. Further investigation of the specificities of the early nAbs and the factors regulating early induction of protective nAbs is needed.
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Affiliation(s)
- Melanie R Walker
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Preston Leung
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Auda A Eltahla
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Alexander Underwood
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Arunasingam Abayasingam
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Nicholas A Brasher
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Hui Li
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Bing-Ru Wu
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Lisa Maher
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia
| | - Fabio Luciani
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia.,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Andrew R Lloyd
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia
| | - Rowena A Bull
- Viral Immunology Systems Program, The Kirby Institute, Sydney, Australia. .,School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia.
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26
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Single-Dose Vaccination with a Hepatotropic Adeno-associated Virus Efficiently Localizes T Cell Immunity in the Liver with the Potential To Confer Rapid Protection against Hepatitis C Virus. J Virol 2019; 93:JVI.00202-19. [PMID: 31292249 DOI: 10.1128/jvi.00202-19] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 07/03/2019] [Indexed: 12/31/2022] Open
Abstract
Hepatitis C virus (HCV) is a significant contributor to the global disease burden, and development of an effective vaccine is required to eliminate HCV infections worldwide. CD4+ and CD8+ T cell immunity correlates with viral clearance in primary HCV infection, and intrahepatic CD8+ tissue-resident memory T (TRM) cells provide lifelong and rapid protection against hepatotropic pathogens. Consequently, we aimed to develop a vaccine to elicit HCV-specific CD4+ and CD8+ T cells, including CD8+ TRM cells, in the liver, given that HCV primarily infects hepatocytes. To achieve this, we vaccinated wild-type BALB/c mice with a highly immunogenic cytolytic DNA vaccine encoding a model HCV (genotype 3a) nonstructural protein (NS5B) and a mutant perforin (pVAX-NS5B-PRF), as well as a recombinant adeno-associated virus (AAV) encoding NS5B (rAAV-NS5B). A novel fluorescent target array (FTA) was used to map immunodominant CD4+ T helper (TH) cell and cytotoxic CD8+ T cell epitopes of NS5B in vivo, which were subsequently used to design a KdNS5B451-459 tetramer and analyze NS5B-specific T cell responses in vaccinated mice in vivo The data showed that intradermal prime/boost vaccination with pVAX-NS5B-PRF was effective in eliciting TH and cytotoxic CD8+ T cell responses and intrahepatic CD8+ TRM cells, but a single intravenous dose of hepatotropic rAAV-NS5B was significantly more effective. As a T-cell-based vaccine against HCV should ideally result in localized T cell responses in the liver, this study describes primary observations in the context of HCV vaccination that can be used to achieve this goal.IMPORTANCE There are currently at least 71 million individuals with chronic HCV worldwide and almost two million new infections annually. Although the advent of direct-acting antivirals (DAAs) offers highly effective therapy, considerable remaining challenges argue against reliance on DAAs for HCV elimination, including high drug cost, poorly developed health infrastructure, low screening rates, and significant reinfection rates. Accordingly, development of an effective vaccine is crucial to HCV elimination. An HCV vaccine that elicits T cell immunity in the liver will be highly protective for the following reasons: (i) T cell responses against nonstructural proteins of the virus are associated with clearance of primary infection, and (ii) long-lived liver-resident T cells alone can protect against malaria infection of hepatocytes. Thus, in this study we exploit promising vaccination platforms to highlight strategies that can be used to evoke highly functional and long-lived T cell responses in the liver for protection against HCV.
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27
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Wrensch F, Keck ZY, Foung SKH, Baumert TF. Learning from a clinical cohort for HCV vaccine development. J Hepatol 2019; 71:9-11. [PMID: 30992137 PMCID: PMC7613475 DOI: 10.1016/j.jhep.2019.03.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 03/29/2019] [Accepted: 03/29/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Florian Wrensch
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, 67000 Strasbourg, France; Université de Strasbourg, 67000 Strasbourg, France
| | - Zhen-Yong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, United States
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, United States
| | - Thomas F Baumert
- Inserm, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, 67000 Strasbourg, France; Université de Strasbourg, 67000 Strasbourg, France; Institut Hospitalo-Universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France; Institut Universitaire de France, 75231 Paris, France.
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28
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Bailey JR, Barnes E, Cox AL. Approaches, Progress, and Challenges to Hepatitis C Vaccine Development. Gastroenterology 2019; 156:418-430. [PMID: 30268785 PMCID: PMC6340767 DOI: 10.1053/j.gastro.2018.08.060] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/12/2018] [Accepted: 08/14/2018] [Indexed: 12/16/2022]
Abstract
Risk factors for hepatitis C virus (HCV) infection vary, and there were an estimated 1.75 million new cases worldwide in 2015. The World Health Organization aims for a 90% reduction in new HCV infections by 2030. An HCV vaccine would prevent transmission, regardless of risk factors, and significantly reduce the global burden of HCV-associated disease. Barriers to development include virus diversity, limited models for testing vaccines, and our incomplete understanding of protective immune responses. Although highly effective vaccines could prevent infection altogether, immune responses that increase the rate of HCV clearance and prevent chronic infection may be sufficient to reduce disease burden. Adjuvant envelope or core protein and virus-vectored nonstructural antigen vaccines have been tested in healthy volunteers who are not at risk for HCV infection; viral vectors encoding nonstructural proteins are the only vaccine strategy to be tested in at-risk individuals. Despite development challenges, a prophylactic vaccine is necessary for global control of HCV.
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Affiliation(s)
- Justin R. Bailey
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Eleanor Barnes
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine and the Oxford NIHR Biomedical Research Centre, Oxford University, UK
| | - Andrea L. Cox
- Division of Infectious Diseases, Johns Hopkins University School of Medicine, Baltimore, Maryland,Reprint requests Address requests for reprints to: Andrea L. Cox, MD, PhD, Division of Infectious Diseases, Johns Hopkins University School of Medicine, 551 Rangos Building, 855 N Wolfe Street, Baltimore, Maryland 21205. fax: (443)769-1221.
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29
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McConnell M, Lim JK. Hepatitis C Vaccine Development in the Era of Direct-Acting Antivirals. Clin Liver Dis (Hoboken) 2018; 12:118-121. [PMID: 30988925 PMCID: PMC6385923 DOI: 10.1002/cld.753] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 08/06/2018] [Indexed: 02/04/2023] Open
Affiliation(s)
- Matthew McConnell
- Section of Digestive Diseases and Yale Liver CenterYale University School of MedicineNew HavenCT
| | - Joseph K. Lim
- Section of Digestive Diseases and Yale Liver CenterYale University School of MedicineNew HavenCT
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30
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Underwood AP, Walker MR, Brasher NA, Eltahla AA, Maher L, Luciani F, Lloyd AR, Bull RA. Understanding the Determinants of BnAb Induction in Acute HCV Infection. Viruses 2018; 10:E659. [PMID: 30469363 PMCID: PMC6266478 DOI: 10.3390/v10110659] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Revised: 10/31/2018] [Accepted: 11/16/2018] [Indexed: 12/16/2022] Open
Abstract
Despite recent advances in curative therapy, hepatitis C virus (HCV) still remains a global threat. In order to achieve global elimination, a prophylactic vaccine should be considered high priority. Previous immunogens used to induce broad neutralising antibodies (BnAbs) have been met with limited success. To improve immunogen design, factors associated with the early development of BnAbs in natural infection must first be understood. In this study, 43 subjects identified with acute HCV were analysed longitudinally using a panel of heterogeneous HCV pseudoparticles (HCVpp), to understand the emergence of BnAbs. Compared to those infected with a single genotype, early BnAb development was associated with subjects co-infected with at least 2 HCV subtypes during acute infection. In those that were mono-infected, BnAbs were seen to emerge with increasing viral persistence. If subjects acquired a secondary infection, nAb breadth was seen to boost upon viral re-exposure. Importantly, this data highlights the potential for multivalent and prime-boost vaccine strategies to induce BnAbs against HCV in humans. However, the data also indicate that the infecting genotype may influence the development of BnAbs. Therefore, the choice of antigen will need to be carefully considered in future vaccine trials.
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Affiliation(s)
- Alexander P Underwood
- School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Melanie R Walker
- School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Nicholas A Brasher
- School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Auda A Eltahla
- School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Lisa Maher
- School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Fabio Luciani
- School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Andrew R Lloyd
- School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia.
| | - Rowena A Bull
- School of Medical Sciences and the Kirby Institute, Faculty of Medicine, UNSW Australia, Sydney, NSW 2052, Australia.
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31
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Kinchen VJ, Bailey JR. Defining Breadth of Hepatitis C Virus Neutralization. Front Immunol 2018; 9:1703. [PMID: 30116237 PMCID: PMC6082923 DOI: 10.3389/fimmu.2018.01703] [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: 04/03/2018] [Accepted: 07/10/2018] [Indexed: 12/13/2022] Open
Abstract
Extraordinary genetic diversity is a hallmark of hepatitis C virus (HCV). Therefore, accurate measurement of the breadth of antibody neutralizing activity across diverse HCV isolates is key to defining correlates of immune protection against the virus, and essential to guide vaccine development. Panels of HCV pseudoparticle (HCVpp) or replication-competent cell culture viruses (HCVcc) can be used to measure neutralizing breadth of antibodies. These in vitro assays have been used to define neutralizing breadth of antibodies in serum, to characterize broadly neutralizing monoclonal antibodies, and to identify mechanisms of HCV resistance to antibody neutralization. Recently, larger and more diverse panels of both HCVpp and HCVcc have been described that better represent the diversity of circulating HCV strains, but further work is needed to expand and standardize these neutralization panels.
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Affiliation(s)
- Valerie J Kinchen
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Justin R Bailey
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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32
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Wrensch F, Crouchet E, Ligat G, Zeisel MB, Keck ZY, Foung SKH, Schuster C, Baumert TF. Hepatitis C Virus (HCV)-Apolipoprotein Interactions and Immune Evasion and Their Impact on HCV Vaccine Design. Front Immunol 2018; 9:1436. [PMID: 29977246 PMCID: PMC6021501 DOI: 10.3389/fimmu.2018.01436] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 06/11/2018] [Indexed: 12/15/2022] Open
Abstract
With more than 71 million people chronically infected, hepatitis C virus (HCV) is one of the leading causes of liver disease and hepatocellular carcinoma. While efficient antiviral therapies have entered clinical standard of care, the development of a protective vaccine is still elusive. Recent studies have shown that the HCV life cycle is closely linked to lipid metabolism. HCV virions associate with hepatocyte-derived lipoproteins to form infectious hybrid particles that have been termed lipo-viro-particles. The close association with lipoproteins is not only critical for virus entry and assembly but also plays an important role during viral pathogenesis and for viral evasion from neutralizing antibodies. In this review, we summarize recent findings on the functional role of apolipoproteins for HCV entry and assembly. Furthermore, we highlight the impact of HCV-apolipoprotein interactions for evasion from neutralizing antibodies and discuss the consequences for antiviral therapy and vaccine design. Understanding these interactions offers novel strategies for the development of an urgently needed protective vaccine.
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Affiliation(s)
- Florian Wrensch
- INSERM, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France.,Université de Strasbourg, Strasbourg, France
| | - Emilie Crouchet
- INSERM, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France.,Université de Strasbourg, Strasbourg, France
| | - Gaetan Ligat
- INSERM, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France.,Université de Strasbourg, Strasbourg, France
| | - Mirjam B Zeisel
- INSERM, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France.,Université de Strasbourg, Strasbourg, France.,INSERM U1052, CNRS UMR 5286, Cancer Research Center of Lyon (CRCL), Université de Lyon (UCBL), Lyon, France
| | - 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
| | - Catherine Schuster
- INSERM, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France.,Université de Strasbourg, Strasbourg, France
| | - Thomas F Baumert
- INSERM, U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France.,Université de Strasbourg, Strasbourg, France.,Institut Hospitalo-Universitaire, Pôle Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.,Institut Universitaire de France, Paris, France
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33
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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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34
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Keck ML, Wrensch F, Pierce BG, Baumert TF, Foung SKH. Mapping Determinants of Virus Neutralization and Viral Escape for Rational Design of a Hepatitis C Virus Vaccine. Front Immunol 2018; 9:1194. [PMID: 29904384 PMCID: PMC5991293 DOI: 10.3389/fimmu.2018.01194] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/14/2018] [Indexed: 12/20/2022] Open
Abstract
Hepatitis C virus (HCV) continues to spread worldwide with an annual increase of 1.75 million new infections. The number of HCV cases in the U.S. is now greater than the number of HIV cases and is increasing in young adults because of the opioid epidemic sweeping the country. HCV-related liver disease is the leading indication of liver transplantation. An effective vaccine is of paramount importance to control and prevent HCV infection. While this vaccine will need to induce both cellular and humoral immunity, this review is focused on the required antibody responses. For highly variable viruses, such as HCV, isolation and characterization of monoclonal antibodies mediating broad virus neutralization are an important guide for vaccine design. The viral envelope glycoproteins, E1 and E2, are the main targets of these antibodies. Epitopes on the E2 protein have been studied more extensively than epitopes on E1, due to higher antibody targeting that reflects these epitopes having higher degrees of immunogenicity. E2 epitopes are overall organized in discrete clusters of overlapping epitopes that ranged from high conservation to high variability. Other epitopes on E1 and E1E2 also are targets of neutralizing antibodies. Taken together, these regions are important for vaccine design. Another element in vaccine design is based on information on how the virus escapes from broadly neutralizing antibodies. Escape mutations can occur within the epitopes that are involved in antibody binding and in regions that are not involved in their epitopes, but nonetheless reduce the efficiency of neutralizing antibodies. An understanding on the specificities of a protective B cell response, the molecular locations of these epitopes on E1, E2, and E1E2, and the mechanisms, which enable the virus to negatively modulate neutralizing antibody responses to these regions will provide the necessary guidance for vaccine design.
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Affiliation(s)
- Mei-Le Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, United States
| | - Florian Wrensch
- INSERM U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France.,Université de Strasbourg, Strasbourg, France
| | - 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
| | - Thomas F Baumert
- INSERM U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France.,Université de Strasbourg, Strasbourg, France
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, United States
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35
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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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Lavie M, Hanoulle X, Dubuisson J. Glycan Shielding and Modulation of Hepatitis C Virus Neutralizing Antibodies. Front Immunol 2018; 9:910. [PMID: 29755477 PMCID: PMC5934428 DOI: 10.3389/fimmu.2018.00910] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/12/2018] [Indexed: 12/11/2022] Open
Abstract
Hepatitis C virus (HCV) envelope glycoprotein heterodimer, E1E2, plays an essential role in virus entry and assembly. Furthermore, due to their exposure at the surface of the virion, these proteins are the major targets of anti-HCV neutralizing antibodies. Their ectodomain are heavily glycosylated with up to 5 sites on E1 and up to 11 sites on E2 modified by N-linked glycans. Thus, one-third of the molecular mass of E1E2 heterodimer corresponds to glycans. Despite the high sequence variability of E1 and E2, N-glycosylation sites of these proteins are generally conserved among the seven major HCV genotypes. N-glycans have been shown to be involved in E1E2 folding and modulate different functions of the envelope glycoproteins. Indeed, site-directed mutagenesis studies have shown that specific glycans are needed for virion assembly and infectivity. They can notably affect envelope protein entry functions by modulating their affinity for HCV receptors and their fusion activity. Importantly, glycans have also been shown to play a key role in immune evasion by masking antigenic sites targeted by neutralizing antibodies. It is well known that the high mutational rate of HCV polymerase facilitates the appearance of neutralization resistant mutants, and occurrence of mutations leading to glycan shifting is one of the mechanisms used by this virus to escape host humoral immune response. As a consequence of the importance of the glycan shield for HCV immune evasion, the deletion of N-glycans also leads to an increase in E1E2 immunogenicity and can induce a more potent antibody response against HCV.
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Affiliation(s)
- Muriel Lavie
- University of Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection & Immunity of Lille, Lille, France
| | - Xavier Hanoulle
- University of Lille, CNRS, UMR 8576, UGSF, Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Jean Dubuisson
- University of Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection & Immunity of Lille, Lille, France
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