1
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Kundu J, Le HT, Logan M, Hockman D, Landi A, Crawford K, Wininger M, Johnson J, Kundu JK, Tiffney EA, Urbanowicz RA, Ball JK, Bailey JR, Bukh J, Law M, Foung S, Tyrrell DL, Houghton M, Law JL. Recombinant H77C gpE1/gpE2 heterodimer elicits superior HCV cross-neutralisation than H77C gpE2 alone. J Hepatol 2024:S0168-8278(24)02335-3. [PMID: 38986744 DOI: 10.1016/j.jhep.2024.06.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 07/12/2024]
Abstract
BACKGROUND & AIMS An optimal HCV vaccine requires the induction of antibodies that neutralise the infectivity of many heterogenous viral isolates. In this study, we have focused on determining the optimal recombinant envelope glycoprotein component to elicit cross-neutralising antibodies against global HCV genotypes. We compared the immunoreactivity and antigenicity of the HCV genotype 1a strain H77C-derived envelope glycoprotein heterodimer gpE1/gpE2 with that of recombinant gpE2 alone. METHODS Characterisation of the envelope glycoproteins was accomplished by determining their ability to bind to a panel of broadly cross-neutralising monoclonal antibodies. Immunogenicity was determined by testing the ability of vaccine antisera to neutralise the infectivity in vitro of a panel of pseudotyped HCV particles in which gpE1/gpE2 derived from representative isolates of the major global HCV genotypes were displayed. RESULTS gpE1/gpE2 binds to more diverse broadly cross-neutralising antibodies than gpE2 alone and elicits a broader profile of cross-neutralising antibodies in animals, especially against more heterologous, non-1a genotypes. While not all heterologous HCV strains can be potently inhibited in vitro by gpE1/gpE2 antisera derived from a single HCV strain, the breadth of heterologous cross-neutralisation is shown to be substantial. CONCLUSIONS Our work supports the inclusion of gpE1/gpE2 in an HCV vaccine in order to maximise the cross-neutralisation of heterogenous HCV isolates. Our data also offers future directions in formulating a cocktail of gpE1/gpE2 antigens from a small selection of HCV genotypes to further enhance cross-neutralisation of global HCV strains and hopefully advance the development of a globally effective HCV vaccine. IMPACT AND IMPLICATIONS An HCV vaccine is urgently required to prevent the high global incidence of HCV infection and disease. Since HCV is a highly heterogeneous virus, it is desirable for a vaccine to elicit antibodies that neutralise the infectivity of most global strains. To this end, we have compared the immunoreactivity and antigenicity of recombinant H77C E1E2 heterodimer with that of H77C E2 alone and show that the former exhibits more cross-neutralising epitopes and demonstrates a broader cross-neutralisation profile in vitro. In addition, our data suggests a way to further broaden cross-neutralisation using a combination of E1E2 antigens derived from a few different HCV clades. Our work is relevant for the development of an effective global HCV vaccine.
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Affiliation(s)
- Juthika Kundu
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Hoa T Le
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Logan
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Darren Hockman
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Abdolamir Landi
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Kevin Crawford
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Mark Wininger
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Janelle Johnson
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Joydeb K Kundu
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - E Alana Tiffney
- Dept of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Richard A Urbanowicz
- Dept of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Jonathan K Ball
- Wolfson Centre for Global Virus Infections, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom; Tropical Disease Biology, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Justin R Bailey
- Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California, USA
| | - Steven Foung
- Department of Pathology, Stanford University, Palo Alto, California, USA
| | - D Lorne Tyrrell
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Houghton
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada.
| | - John Lokman Law
- Li Ka Shing Applied Virology Institute, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
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2
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Zhang H, Bull RA, Quadeer AA, McKay MR. HCV E1 influences the fitness landscape of E2 and may enhance escape from E2-specific antibodies. Virus Evol 2023; 9:vead068. [PMID: 38107333 PMCID: PMC10722114 DOI: 10.1093/ve/vead068] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 09/27/2023] [Accepted: 11/16/2023] [Indexed: 12/19/2023] Open
Abstract
The Hepatitis C virus (HCV) envelope glycoprotein E1 forms a non-covalent heterodimer with E2, the main target of neutralizing antibodies. How E1-E2 interactions influence viral fitness and contribute to resistance to E2-specific antibodies remain largely unknown. We investigate this problem using a combination of fitness landscape and evolutionary modeling. Our analysis indicates that E1 and E2 proteins collectively mediate viral fitness and suggests that fitness-compensating E1 mutations may accelerate escape from E2-targeting antibodies. Our analysis also identifies a set of E2-specific human monoclonal antibodies that are predicted to be especially resilient to escape via genetic variation in both E1 and E2, providing directions for robust HCV vaccine development.
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Affiliation(s)
- Hang Zhang
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, SAR, China
| | - Rowena A Bull
- School of Biomedical Sciences, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW 2052, Australia
- The Kirby Institute for Infection and Immunity, Sydney, NSW 2052, Australia
| | - Ahmed Abdul Quadeer
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, SAR, China
- Department of Electrical and Electronic Engineering, University of Melbourne, Parkville, VIC 3010, Australia
| | - Matthew R McKay
- Department of Electrical and Electronic Engineering, University of Melbourne, Parkville, VIC 3010, Australia
- Department of Microbiology and Immunology, The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC 3000, Australia
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3
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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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4
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Ströh LJ, Krey T. Structural insights into hepatitis C virus neutralization. Curr Opin Virol 2023; 60:101316. [DOI: 10.1016/j.coviro.2023.101316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/12/2023] [Indexed: 03/31/2023]
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5
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Struble EB, Rawson JMO, Stantchev T, Scott D, Shapiro MA. Uses and Challenges of Antiviral Polyclonal and Monoclonal Antibody Therapies. Pharmaceutics 2023; 15:pharmaceutics15051538. [PMID: 37242780 DOI: 10.3390/pharmaceutics15051538] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/04/2023] [Accepted: 05/10/2023] [Indexed: 05/28/2023] Open
Abstract
Viral diseases represent a major public health concerns and ever-present risks for developing into future pandemics. Antiviral antibody therapeutics, either alone or in combination with other therapies, emerged as valuable preventative and treatment options, including during global emergencies. Here we will discuss polyclonal and monoclonal antiviral antibody therapies, focusing on the unique biochemical and physiological properties that make them well-suited as therapeutic agents. We will describe the methods of antibody characterization and potency assessment throughout development, highlighting similarities and differences between polyclonal and monoclonal products as appropriate. In addition, we will consider the benefits and challenges of antiviral antibodies when used in combination with other antibodies or other types of antiviral therapeutics. Lastly, we will discuss novel approaches to the characterization and development of antiviral antibodies and identify areas that would benefit from additional research.
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Affiliation(s)
- Evi B Struble
- Division of Plasma Derivatives, Office of Plasma Protein Therapeutics CMC, Office of Therapeutic Products, Center for Biologics Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Jonathan M O Rawson
- Division of Antivirals, Office of Infectious Diseases, Office of New Drugs, Center for Drug Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Tzanko Stantchev
- Division of Biotechnology Review and Research 1, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Dorothy Scott
- Division of Plasma Derivatives, Office of Plasma Protein Therapeutics CMC, Office of Therapeutic Products, Center for Biologics Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Marjorie A Shapiro
- Division of Biotechnology Review and Research 1, Office of Biotechnology Products, Office of Pharmaceutical Quality, Center for Drug Evaluation and Research, United States Food and Drug Administration, Silver Spring, MD 20993, USA
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6
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Gomez-Escobar E, Roingeard P, Beaumont E. Current Hepatitis C Vaccine Candidates Based on the Induction of Neutralizing Antibodies. Viruses 2023; 15:1151. [PMID: 37243237 PMCID: PMC10220683 DOI: 10.3390/v15051151] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/05/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
The introduction of direct-acting antivirals (DAAs) has revolutionized hepatitis C treatment. Short courses of treatment with these drugs are highly beneficial to patients, eliminating hepatitis C virus (HCV) without adverse effects. However, this outstanding success is tempered by the continuing difficulty of eradicating the virus worldwide. Thus, access to an effective vaccine against HCV is strongly needed to reduce the burden of the disease and contribute to the elimination of viral hepatitis. The recent failure of a T-cell vaccine based on the use of viral vectors expressing the HCV non-structural protein sequences to prevent chronic hepatitis C in drug users has pointed out that the induction of neutralizing antibodies (NAbs) will be essential in future vaccine candidates. To induce NAbs, vaccines must contain the main target of this type of antibody, the HCV envelope glycoproteins (E1 and E2). In this review, we summarize the structural regions in E1 and E2 proteins that are targeted by NAbs and how these proteins are presented in the vaccine candidates currently under development.
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Affiliation(s)
| | - Philippe Roingeard
- Inserm U1259 MAVIVH, Université de Tours and CHRU de Tours, 37000 Tours, France;
| | - Elodie Beaumont
- Inserm U1259 MAVIVH, Université de Tours and CHRU de Tours, 37000 Tours, France;
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7
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Kaczorowska J, Timmerman AL, Deijs M, Kinsella CM, Bakker M, van der Hoek L. Anellovirus evolution during long-term chronic infection. Virus Evol 2023; 9:vead001. [PMID: 36726484 PMCID: PMC9885978 DOI: 10.1093/ve/vead001] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/19/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023] Open
Abstract
Human anelloviruses (AVs) are extremely genetically diverse, are widespread in the human population, and cause chronic infections. However, the evolutionary dynamics of AVs within single hosts is currently unknown, and it is unclear whether these changes have an implication on the long-term persistence of AVs in the host. Here, we assessed the evolutionary dynamics of six AV lineages during 30 years of chronic infection at single host resolution. The total number of substitutions and the number of variable sites increased over time. However, not all substitutions reached population fixation, showing that AV lineages form heterogeneous swarms within the host. Most substitutions occurred within a hypervariable region (HVR) located between nucleotide positions 800 and 1,300 of ORF1, which is known to be located within the spike domain. Different regions of the ORF1 gene undergo either positive or negative selection pressure. Sites under strong diversifying selection pressure were detected in the HVR, while the majority of the sites under purifying selection were detected outside this region. The HVR may play the role of an immunological decoy that prevents antibodies from binding to more vulnerable parts of ORF1. Moreover, the frequent substitutions in this region may increase the chances of AV particles escaping immune recognition.
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Affiliation(s)
| | | | - Martin Deijs
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands,Amsterdam Institute for Infection and Immunity, Postbus 22660, Amsterdam 1100 DD, The Netherlands
| | | | - Margreet Bakker
- Department of Medical Microbiology and Infection Prevention, Laboratory of Experimental Virology, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands,Amsterdam Institute for Infection and Immunity, Postbus 22660, Amsterdam 1100 DD, The Netherlands
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8
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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: 22] [Impact Index Per Article: 11.0] [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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9
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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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10
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Tisthammer KH, Solis C, Orcales F, Nzerem M, Winstead R, Dong W, Joy JB, Pennings PS. Assessing in vivo mutation frequencies and creating a high-resolution genome-wide map of fitness costs of Hepatitis C virus. PLoS Genet 2022; 18:e1010179. [PMID: 35500034 PMCID: PMC9113599 DOI: 10.1371/journal.pgen.1010179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 05/17/2022] [Accepted: 03/30/2022] [Indexed: 11/18/2022] Open
Abstract
Like many viruses, Hepatitis C Virus (HCV) has a high mutation rate, which helps the virus adapt quickly, but mutations come with fitness costs. Fitness costs can be studied by different approaches, such as experimental or frequency-based approaches. The frequency-based approach is particularly useful to estimate in vivo fitness costs, but this approach works best with deep sequencing data from many hosts are. In this study, we applied the frequency-based approach to a large dataset of 195 patients and estimated the fitness costs of mutations at 7957 sites along the HCV genome. We used beta regression and random forest models to better understand how different factors influenced fitness costs. Our results revealed that costs of nonsynonymous mutations were three times higher than those of synonymous mutations, and mutations at nucleotides A or T had higher costs than those at C or G. Genome location had a modest effect, with lower costs for mutations in HVR1 and higher costs for mutations in Core and NS5B. Resistance mutations were, on average, costlier than other mutations. Our results show that in vivo fitness costs of mutations can be site and virus specific, reinforcing the utility of constructing in vivo fitness cost maps of viral genomes.
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Affiliation(s)
- Kaho H. Tisthammer
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- * E-mail:
| | - Caroline Solis
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Faye Orcales
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Madu Nzerem
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Ryan Winstead
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Weiyan Dong
- BC Centre for Excellence in HIV/AIDS, Vancouver, British Colombia, Canada
| | - Jeffrey B. Joy
- BC Centre for Excellence in HIV/AIDS, Vancouver, British Colombia, Canada
- Division of Infectious Diseases, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Bioinformatics Programme, University of British Columbia, Vancouver, British Colombia, Canada
| | - Pleuni S. Pennings
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
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11
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Zhang H, Quadeer AA, McKay MR. Evolutionary modeling reveals enhanced mutational flexibility of HCV subtype 1b compared with 1a. iScience 2022; 25:103569. [PMID: 34988406 PMCID: PMC8704487 DOI: 10.1016/j.isci.2021.103569] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 11/19/2021] [Accepted: 12/02/2021] [Indexed: 11/24/2022] Open
Abstract
Hepatitis C virus (HCV) is a leading cause of liver-associated disease and liver cancer. Of the major HCV subtypes, patients infected with subtype 1b have been associated with having a higher risk of developing chronic infection and hepatocellular carcinoma. However, underlying reasons for this increased disease severity remain unknown. Here, we provide an evolutionary rationale, based on a comparative study of fitness landscape and in-host evolutionary models of the E2 glycoprotein of HCV subtypes 1a and 1b. Our analysis demonstrates that a higher chronicity rate of 1b may be attributed to lower fitness constraints, enabling 1b viruses to more easily escape antibody responses. More generally, our results suggest that differences in evolutionary constraints between HCV subtypes may be an important factor in mediating distinct disease outcomes. Our analysis also identifies antibodies that appear escape-resistant against both subtypes 1a and 1b, providing directions for designing HCV vaccines having cross-subtype protection.
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Affiliation(s)
- Hang Zhang
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, SAR, China
| | - Ahmed A. Quadeer
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, SAR, China
| | - Matthew R. McKay
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, SAR, China
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, SAR, China
- Department of Electrical and Electronic Engineering, University of Melbourne, Melbourne, VIC, Australia
- Department of Microbiology and Immunology, University of Melbourne, The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
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12
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Augestad EH, Bukh J, Prentoe J. Hepatitis C virus envelope protein dynamics and the link to hypervariable region 1. Curr Opin Virol 2021; 50:69-75. [PMID: 34403905 DOI: 10.1016/j.coviro.2021.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/22/2021] [Accepted: 07/22/2021] [Indexed: 12/11/2022]
Abstract
Conformational dynamics of viral envelope proteins seem to be involved in mediating evasion from neutralizing antibodies (NAbs) by mechanisms that limit exposure of conserved protein motifs. For hepatitis C virus (HCV), molecular studies have only recently begun to unveil how such dynamics of the envelope protein heterodimer, E1/E2, are linked to viral entry and NAb evasion. Here, we review data suggesting that E1/E2 exists in an equilibrium between theoretical 'open' (NAb-sensitive) and 'closed' (NAb-resistant) conformational states. We describe how this equilibrium is influenced by viral sequence polymorphisms and that it is critically dependent on the N-terminal region of E2, termed hypervariable region 1 (HVR1). Finally, we discuss how it appears that the virus binding site for the HCV entry co-receptor CD81 is less available in 'closed' E1/E2 states and that NAb-resistant viruses require a more intricate entry pathway involving also the entry co-receptor, SR-BI.
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Affiliation(s)
- Elias H Augestad
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Copenhagen, Denmark; Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Copenhagen, Denmark; Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Copenhagen, Denmark; Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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13
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Where to Next? Research Directions after the First Hepatitis C Vaccine Efficacy Trial. Viruses 2021; 13:v13071351. [PMID: 34372558 PMCID: PMC8310243 DOI: 10.3390/v13071351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/03/2021] [Accepted: 07/08/2021] [Indexed: 11/17/2022] Open
Abstract
Thirty years after its discovery, the hepatitis C virus (HCV) remains a leading cause of liver disease worldwide. Given that many countries continue to experience high rates of transmission despite the availability of potent antiviral therapies, an effective vaccine is seen as critical for the elimination of HCV. The recent failure of the first vaccine efficacy trial for the prevention of chronic HCV confirmed suspicions that this virus will be a challenging vaccine target. Here, we examine the published data from this first efficacy trial along with the earlier clinical and pre-clinical studies of the vaccine candidate and then discuss three key research directions expected to be important in ongoing and future HCV vaccine development. These include the following: 1. design of novel immunogens that generate immune responses to genetically diverse HCV genotypes and subtypes, 2. strategies to elicit broadly neutralizing antibodies against envelope glycoproteins in addition to cytotoxic and helper T cell responses, and 3. consideration of the unique immunological status of individuals most at risk for HCV infection, including those who inject drugs, in vaccine platform development and early immunogenicity trials.
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14
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Sevvana M, Keck Z, Foung SK, Kuhn RJ. Structural perspectives on HCV humoral immune evasion mechanisms. Curr Opin Virol 2021; 49:92-101. [PMID: 34091143 DOI: 10.1016/j.coviro.2021.05.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 05/15/2021] [Accepted: 05/17/2021] [Indexed: 12/20/2022]
Abstract
The molecular mechanisms of hepatitis C virus (HCV) persistence and pathogenesis are poorly understood. The design of an effective HCV vaccine is challenging despite a robust humoral immune response against closely related strains of HCV. This is primarily because of the huge genetic diversity of HCV and the molecular evolution of various virus escape mechanisms. These mechanisms are steered by the presence of a high mutational rate in HCV, structural plasticity of the immunodominant regions on the virion surface of diverse HCV genotypes, and constant amino acid substitutions on key structural components of HCV envelope glycoproteins. Here, we review the molecular basis of neutralizing antibody (nAb)-mediated immune response against diverse HCV variants, HCV-steered humoral immune evasion strategies and explore the essential structural elements to consider for designing a universal HCV vaccine. Structural perspectives on key escape pathways mediated by a point mutation within the epitope, allosteric modulation of the epitope by distant mutations and glycan shift on envelope glycoproteins will be highlighted (abstract graphic).
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Affiliation(s)
- Madhumati Sevvana
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47904, USA; Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN 47904, USA
| | - Zhenyong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Steven Kh Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - Richard J Kuhn
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47904, USA; Purdue Institute of Inflammation, Immunology, and Infectious Disease, Purdue University, West Lafayette, IN 47904, USA.
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15
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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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16
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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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17
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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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18
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To Include or Occlude: Rational Engineering of HCV Vaccines for Humoral Immunity. Viruses 2021; 13:v13050805. [PMID: 33946211 PMCID: PMC8146105 DOI: 10.3390/v13050805] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/16/2021] [Accepted: 04/28/2021] [Indexed: 02/07/2023] Open
Abstract
Direct-acting antiviral agents have proven highly effective at treating existing hepatitis C infections but despite their availability most countries will not reach the World Health Organization targets for elimination of HCV by 2030. A prophylactic vaccine remains a high priority. Whilst early vaccines focused largely on generating T cell immunity, attention is now aimed at vaccines that generate humoral immunity, either alone or in combination with T cell-based vaccines. High-resolution structures of hepatitis C viral glycoproteins and their interaction with monoclonal antibodies isolated from both cleared and chronically infected people, together with advances in vaccine technologies, provide new avenues for vaccine development.
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19
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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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20
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Tisthammer KH, Dong W, Joy JB, Pennings PS. Comparative Analysis of Within-Host Mutation Patterns and Diversity of Hepatitis C Virus Subtypes 1a, 1b, and 3a. Viruses 2021; 13:511. [PMID: 33808782 PMCID: PMC8003410 DOI: 10.3390/v13030511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 03/17/2021] [Indexed: 12/13/2022] Open
Abstract
Understanding within-host evolution is critical for predicting viral evolutionary outcomes, yet such studies are currently lacking due to difficulty involving human subjects. Hepatitis C virus (HCV) is an RNA virus with high mutation rates. Its complex evolutionary dynamics and extensive genetic diversity are demonstrated in over 67 known subtypes. In this study, we analyzed within-host mutation frequency patterns of three HCV subtypes, using a large number of samples obtained from treatment-naïve participants by next-generation sequencing. We report that overall mutation frequency patterns are similar among subtypes, yet subtype 3a consistently had lower mutation frequencies and nucleotide diversity, while subtype 1a had the highest. We found that about 50% of genomic sites are highly conserved across subtypes, which are likely under strong purifying selection. We also compared within-host and between-host selective pressures, which revealed that Hyper Variable Region 1 within hosts was under positive selection, but was under slightly negative selection between hosts, which indicates that many mutations created within hosts are removed during the transmission bottleneck. Examining the natural prevalence of known resistance-associated variants showed their consistent existence in the treatment-naïve participants. These results provide insights into the differences and similarities among HCV subtypes that may be used to develop and improve HCV therapies.
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Affiliation(s)
- Kaho H. Tisthammer
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA;
| | - Weiyan Dong
- BC Centre for Excellence in HIV/AIDS, Vancouver, BC V6Z 1Y6, Canada; (W.D.); (J.B.J.)
| | - Jeffrey B. Joy
- BC Centre for Excellence in HIV/AIDS, Vancouver, BC V6Z 1Y6, Canada; (W.D.); (J.B.J.)
- Division of Infectious Diseases, Department of Medicine, University of British Columbia, Vancouver, BC V5Z 3J5, Canada
- Bioinformatics Programme, University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Pleuni S. Pennings
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA;
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21
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Keyhole Limpet Hemocyanin-Conjugated Peptides from Hepatitis C Virus Glycoproteins Elicit Neutralizing Antibodies in BALB/c Mice. J Immunol Res 2021; 2021:3108157. [PMID: 33532506 PMCID: PMC7834783 DOI: 10.1155/2021/3108157] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 12/18/2020] [Accepted: 01/05/2021] [Indexed: 12/22/2022] Open
Abstract
Currently, no vaccine to prevent hepatitis C virus (HCV) infection is available. A major challenge in developing an HCV vaccine is the high diversity of HCV sequences. The purpose of immunization with viral glycoproteins is to induce a potent and long-lasting cellular and humoral immune response. However, this strategy only achieves limited protection, and antigen selection plays a crucial role in vaccine design. In this study, we investigated the humoral immune responses induced by intraperitoneal injection of keyhole limpet hemocyanin conjugated with 4 highly conserved peptides, including amino acids [aa]317-325 from E1 and aa418-429, aa502-518, and aa685-693 from E2, or 3 peptides from hypervariable region 1 (HVR1) of E2, including the N terminus of HVR1 (N-HVR1, aa384-396), C terminus of HVR1 (C-HVR1, aa397-410), and HVR1 in BALB/c mice. The neutralizing activity against HCV genotypes 1-6 was assessed using the cell culture HCV (HCVcc) system. The results showed that the 4 conserved peptides efficiently induced antibodies with potent neutralizing activity against 3 or 4 genotypes. Antibodies induced by aa685-693 conferred potent protection (>50%) against genotypes 2, 4, and 5. Peptide N-HVR1 elicited antibodies with the most potent neutralization activities against 3 HCV genotypes: TNcc(1a), S52(3a), and ED43(4a). These findings suggested that peptides within HCV glycoproteins could serve as potent immunogens for vaccine design and development.
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22
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Pierce BG, Keck ZY, Wang R, Lau P, Garagusi K, Elkholy K, Toth EA, Urbanowicz RA, Guest JD, Agnihotri P, Kerzic MC, Marin A, Andrianov AK, Ball JK, Mariuzza RA, Fuerst TR, Foung SKH. Structure-Based Design of Hepatitis C Virus E2 Glycoprotein Improves Serum Binding and Cross-Neutralization. J Virol 2020; 94:e00704-20. [PMID: 32878891 PMCID: PMC7592221 DOI: 10.1128/jvi.00704-20] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Accepted: 08/20/2020] [Indexed: 12/22/2022] Open
Abstract
An effective vaccine for hepatitis C virus (HCV) is a major unmet need, and it requires an antigen that elicits immune responses to key conserved epitopes. Based on structures of antibodies targeting HCV envelope glycoprotein E2, we designed immunogens to modulate the structure and dynamics of E2 and favor induction of broadly neutralizing antibodies (bNAbs) in the context of a vaccine. These designs include a point mutation in a key conserved antigenic site to stabilize its conformation, as well as redesigns of an immunogenic region to add a new N-glycosylation site and mask it from antibody binding. Designs were experimentally characterized for binding to a panel of human monoclonal antibodies (HMAbs) and the coreceptor CD81 to confirm preservation of epitope structure and preferred antigenicity profile. Selected E2 designs were tested for immunogenicity in mice, with and without hypervariable region 1, which is an immunogenic region associated with viral escape. One of these designs showed improvement in polyclonal immune serum binding to HCV pseudoparticles and neutralization of isolates associated with antibody resistance. These results indicate that antigen optimization through structure-based design of the envelope glycoproteins is a promising route to an effective vaccine for HCV.IMPORTANCE Hepatitis C virus infects approximately 1% of the world's population, and no vaccine is currently available. Due to the high variability of HCV and its ability to actively escape the immune response, a goal of HCV vaccine design is to induce neutralizing antibodies that target conserved epitopes. Here, we performed structure-based design of several epitopes of the HCV E2 envelope glycoprotein to engineer its antigenic properties. Designs were tested in vitro and in vivo, demonstrating alteration of the E2 antigenic profile in several cases, and one design led to improvement of cross-neutralization of heterologous viruses. This represents a proof of concept that rational engineering of HCV envelope glycoproteins can be used to modulate E2 antigenicity and optimize a vaccine for this challenging viral target.
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Affiliation(s)
- Brian G Pierce
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Zhen-Yong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Ruixue Wang
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
| | - Patrick Lau
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Kyle Garagusi
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
| | - Khadija Elkholy
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
| | - Eric A Toth
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
| | - Richard A Urbanowicz
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom
| | - Johnathan D Guest
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Pragati Agnihotri
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Melissa C Kerzic
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Alexander Marin
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
| | - Alexander K Andrianov
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
| | - Jonathan K Ball
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, United Kingdom
| | - Roy A Mariuzza
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Thomas R Fuerst
- University of Maryland Institute for Bioscience and Biotechnology Research, Rockville, Maryland, USA
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, USA
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
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23
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Mosa AI, Urbanowicz RA, AbouHaidar MG, Tavis JE, Ball JK, Feld JJ. A bivalent HCV peptide vaccine elicits pan-genotypic neutralizing antibodies in mice. Vaccine 2020; 38:6864-6867. [PMID: 32900542 DOI: 10.1016/j.vaccine.2020.08.066] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/19/2020] [Accepted: 08/25/2020] [Indexed: 11/17/2022]
Abstract
Vaccine development for antigenically variable pathogens has faltered because extreme genetic diversity precludes induction of broadly neutralizing antibodies (nAB) with classical vaccines. Here, using the most variable epitope of any known human pathogen (HVR1 of HCV), we describe a novel approach capable of eliciting broadly neutralizing antibodies targeting highly variable epitopes. Our proof-of-concept vaccine elicited pan-genotypic nAB against HCV variants differing from the immunogen sequences by more than 70% at the amino acid level. These findings suggest broadly nAB to highly variable pathogens can be elicited by vaccines designed to target physicochemically conserved residues within hypervariable epitopes.
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Affiliation(s)
- Alexander I Mosa
- Department of Cell and Systems Biology, University of Toronto, Canada.
| | - Richard A Urbanowicz
- Wolfson Centre for Global Virus Infections, University of Nottingham, UK; School of Life Sciences, University of Nottingham, UK
| | | | - John E Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, United States
| | - Jonathan K Ball
- Wolfson Centre for Global Virus Infections, University of Nottingham, UK; School of Life Sciences, University of Nottingham, UK
| | - Jordan J Feld
- Toronto Centre for Liver Disease, Toronto General Hospital, Sandra Rotman Centre for Global Health, University of Toronto, Canada
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24
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Abstract
Protective vaccines for hypervariable pathogens are urgently needed. It has been proposed that amputating highly variable epitopes from vaccine antigens would induce the production of broadly protective antibodies targeting conserved epitopes. However, so far, these approaches have failed, partially because conserved epitopes are occluded in vivo and partially because co-localizing patterns of immunodominance and antigenic variability render variable epitopes the primary target for antibodies in natural infection. In this Perspective, to recast the challenge of vaccine development for hypervariable pathogens, I evaluate convergent mechanisms of adaptive variation, such as intrahost immune-mediated diversification, spatiotemporally defined antigenic space, and infection-enhancing cross-immunoreactivity. The requirements of broadly protective immune responses targeting variable pathogens are formulated in terms of cross-immunoreactivity, stoichiometric thresholds for neutralization, and the elicitation of antibodies targeting physicochemically conserved signatures within sequence variable domains.
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Affiliation(s)
- Alexander I Mosa
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON, Canada
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25
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Mosa AI, AbouHaidar MG, Urbanowicz RA, Tavis JE, Ball JK, Feld JJ. Role of HVR1 sequence similarity in the cross-genotypic neutralization of HCV. Virol J 2020; 17:140. [PMID: 32948191 PMCID: PMC7499410 DOI: 10.1186/s12985-020-01408-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 08/28/2020] [Indexed: 02/07/2023] Open
Abstract
Despite available treatments, a prophylactic HCV vaccine is needed to achieve elimination targets. HCV vaccine development has faltered largely because the extreme diversity of the virus limits the protective breadth of vaccine elicited antibodies. It is believed that the principle neutralizing epitope in natural infection, HVR1, which is the most variable epitope in HCV, mediates humoral immune escape. So far, efforts to circumvent HVR1 interference in the induction and function of conserved targeting Ab have failed. Efforts to understand factors contributing to cross-neutralization of HVR1 variants have also been limited. Here, following mouse immunizations with two patient-derived HVR1 peptides, we observe cross-genotype neutralization of variants differing at 15/21 positions. Surprisingly, sequence similarity was not associated with cross-neutralization. It appeared neutralization sensitivity was an intrinsic feature of each variant, rather than emergent from the immunogen specific Ab response. These findings provide novel insight into HVR1-mediated immune evasion, with important implications for HCV vaccine design.
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Affiliation(s)
- Alexander I Mosa
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada.
| | - Mounir G AbouHaidar
- Department of Cell and Systems Biology, University of Toronto, Toronto, Canada
| | - Richard A Urbanowicz
- Wolfson Centre for Global Virus Infections, University of Nottingham, Nottingham, UK
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - John E Tavis
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, USA
| | - Jonathan K Ball
- Wolfson Centre for Global Virus Infections, University of Nottingham, Nottingham, UK
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Jordan J Feld
- Toronto Centre for Liver Disease, Toronto General Hospital, Sandra Rotman Centre for Global Health, University of Toronto, Toronto, Canada
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26
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Ströh LJ, Krey T. HCV Glycoprotein Structure and Implications for B-Cell Vaccine Development. Int J Mol Sci 2020; 21:ijms21186781. [PMID: 32947858 PMCID: PMC7555785 DOI: 10.3390/ijms21186781] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/12/2020] [Accepted: 09/14/2020] [Indexed: 02/06/2023] Open
Abstract
Despite the approval of highly efficient direct-acting antivirals in the last decade Hepatitis C virus (HCV) remains a global health burden and the development of a vaccine would constitute an important step towards the control of HCV. The high genetic variability of the viral glycoproteins E1 and E2, which carry the main neutralizing determinants, together with their intrinsic structural flexibility, the high level of glycosylation that shields conserved neutralization epitopes and immune evasion using decoy epitopes renders the design of an efficient vaccine challenging. Recent structural and functional analyses have highlighted the role of the CD81 receptor binding site on E2, which overlaps with those neutralization epitopes within E2 that have been structurally characterized to date. This CD81 binding site consists of three distinct segments including “epitope I”, “epitope II” and the “CD81 binding loop”. In this review we summarize the structural features of the HCV glycoproteins that have been derived from X-ray structures of neutralizing and non-neutralizing antibody fragments complexed with either recombinant E2 or epitope-derived linear peptides. We focus on the current understanding how neutralizing antibodies interact with their cognate antigen, the structural features of the respective neutralization epitopes targeted by nAbs and discuss the implications for informed vaccine design.
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Affiliation(s)
- Luisa J. Ströh
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany;
| | - Thomas Krey
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany;
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, 23562 Luebeck, Germany
- German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 30625 Hannover, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Luebeck-Borstel-Riems, 23562 Luebeck, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, 30625 Hannover, Germany
- Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany
- Correspondence: ; Tel.: +49-(0)451–3101-3101
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27
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Zhao H, Xu L, Bombardi R, Nargi R, Deng Z, Errico JM, Nelson CA, Dowd KA, Pierson TC, Crowe JE, Diamond MS, Fremont DH. Mechanism of differential Zika and dengue virus neutralization by a public antibody lineage targeting the DIII lateral ridge. J Exp Med 2020; 217:jem.20191792. [PMID: 31757867 PMCID: PMC7041715 DOI: 10.1084/jem.20191792] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 10/09/2019] [Accepted: 10/18/2019] [Indexed: 12/20/2022] Open
Abstract
Evaluation of the human antibody response to Zika virus has identified common germline-derived mAbs capable of cross flavivirus neutralization. Zhao et al. provide a detailed mechanistic understanding of how flavivirus infections are prevented in a strain-specific manner by a representative mAb. We previously generated a panel of human monoclonal antibodies (mAbs) against Zika virus (ZIKV) and identified one, ZIKV-116, that shares germline usage with mAbs identified in multiple donors. Here we show that ZIKV-116 interferes with ZIKV infection at a post-cellular attachment step by blocking viral fusion with host membranes. ZIKV-116 recognizes the lateral ridge of envelope protein domain III, with one critical residue varying between the Asian and African strains responsible for differential binding affinity and neutralization potency (E393D). ZIKV-116 also binds to and cross-neutralizes some dengue virus serotype 1 (DENV1) strains, with genotype-dependent inhibition explained by variation in a domain II residue (R204K) that potentially modulates exposure of the distally located, partially cryptic epitope. The V-J reverted germline configuration of ZIKV-116 preferentially binds to and neutralizes an Asian ZIKV strain, suggesting that this epitope may optimally induce related B cell clonotypes. Overall, these studies provide a structural and molecular mechanism for a cross-reactive mAb that uniquely neutralizes ZIKV and DENV1.
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Affiliation(s)
- Haiyan Zhao
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO
| | - Lily Xu
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO
| | - Robin Bombardi
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN
| | - Rachel Nargi
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN
| | - Zengqin Deng
- Department of Cell Biology & Physiology, Washington University School of Medicine, Saint Louis, MO
| | - John M Errico
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO
| | - Christopher A Nelson
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO
| | - Kimberly A Dowd
- Viral Pathogenesis Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - Theodore C Pierson
- Viral Pathogenesis Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD
| | - James E Crowe
- The Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN.,Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN.,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - Michael S Diamond
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO.,Department of Medicine, Washington University School of Medicine, Saint Louis, MO
| | - Daved H Fremont
- Department of Pathology & Immunology, Washington University School of Medicine, Saint Louis, MO.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO.,Department of Biochemistry & Molecular Biophysics, Washington University School of Medicine, Saint Louis, MO
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28
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Kinchen VJ, Massaccesi G, Flyak AI, Mankowski MC, Colbert MD, Osburn WO, Ray SC, Cox AL, Crowe JE, Bailey JR. Plasma deconvolution identifies broadly neutralizing antibodies associated with hepatitis C virus clearance. J Clin Invest 2019; 129:4786-4796. [PMID: 31408439 DOI: 10.1172/jci130720] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A vaccine for hepatitis C virus (HCV) is urgently needed. Development of broadly-neutralizing plasma antibodies during acute infection is associated with HCV clearance, but the viral epitopes of these plasma antibodies are unknown. Identification of these epitopes could define the specificity and function of neutralizing antibodies (NAbs) that should be induced by a vaccine. Here, we present development and application of a high-throughput method that deconvolutes polyclonal anti-HCV NAbs in plasma, delineating the epitope specificities of anti-HCV NAbs in acute infection plasma of forty-four humans with subsequent clearance or persistence of HCV. Remarkably, we identified multiple broadly neutralizing antibody (bNAb) combinations that were associated with greater plasma neutralizing breadth and with HCV clearance. These studies have potential to inform new strategies for vaccine development by identifying bNAb combinations in plasma associated with natural clearance of HCV, while also providing a high-throughput assay that could identify these responses after vaccination trials.
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Affiliation(s)
- Valerie J Kinchen
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Guido Massaccesi
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Andrew I Flyak
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Madeleine C Mankowski
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Michelle D Colbert
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - William O Osburn
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Stuart C Ray
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Andrea L Cox
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - James E Crowe
- Department of Pediatrics, Vanderbilt University Medical Center.,Department of Pathology, Microbiology, and Immunology, and.,Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Vanderbilt University, Nashville, Tennessee, USA
| | - Justin R Bailey
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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29
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Broadly Neutralizing Antibodies Targeting New Sites of Vulnerability in Hepatitis C Virus E1E2. J Virol 2019; 93:JVI.02070-18. [PMID: 31068427 DOI: 10.1128/jvi.02070-18] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 05/01/2019] [Indexed: 02/08/2023] Open
Abstract
Increasing evidence indicates that broadly neutralizing antibodies (bNAbs) play an important role in immune-mediated control of hepatitis C virus (HCV) infection, but the relative contribution of neutralizing antibodies targeting antigenic sites across the HCV envelope (E1 and E2) proteins is unclear. Here, we isolated thirteen E1E2-specific monoclonal antibodies (MAbs) from B cells of a single HCV-infected individual who cleared one genotype 1a infection and then became persistently infected with a second genotype 1a strain. These MAbs bound six distinct discontinuous antigenic sites on the E1 protein, the E2 protein, or the E1E2 heterodimer. Three antigenic sites, designated AS108, AS112 (an N-terminal E1 site), and AS146, were distinct from previously described antigenic regions (ARs) 1 to 5 and E1 sites. Antibodies targeting four sites (AR3, AR4-5, AS108, and AS146) were broadly neutralizing. These MAbs also displayed distinct patterns of relative neutralizing potency (i.e., neutralization profiles) across a panel of diverse HCV strains, which led to complementary neutralizing breadth when they were tested in combination. Overall, this study demonstrates that HCV bNAb epitopes are not restricted to previously described antigenic sites, expanding the number of sites that could be targeted for vaccine development.IMPORTANCE Worldwide, more than 70 million people are infected with hepatitis C virus (HCV), which is a leading cause of hepatocellular carcinoma and liver transplantation. Despite the development of potent direct acting antivirals (DAAs) for HCV treatment, a vaccine is urgently needed due to the high cost of treatment and the possibility of reinfection after cure. Induction of multiple broadly neutralizing antibodies (bNAbs) that target distinct epitopes on the HCV envelope proteins is one approach to vaccine development. However, antigenic sites targeted by bNAbs in individuals with spontaneous control of HCV have not been fully defined. In this study, we characterize 13 monoclonal antibodies (MAbs) from a single person who cleared an HCV infection without treatment, and we identify 3 new sites targeted by neutralizing antibodies. The sites targeted by these MAbs could inform HCV vaccine development.
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30
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Chigbu DI, Loonawat R, Sehgal M, Patel D, Jain P. Hepatitis C Virus Infection: Host⁻Virus Interaction and Mechanisms of Viral Persistence. Cells 2019; 8:cells8040376. [PMID: 31027278 PMCID: PMC6523734 DOI: 10.3390/cells8040376] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 03/25/2019] [Accepted: 04/17/2019] [Indexed: 12/11/2022] Open
Abstract
Hepatitis C (HCV) is a major cause of liver disease, in which a third of individuals with chronic HCV infections may develop liver cirrhosis. In a chronic HCV infection, host immune factors along with the actions of HCV proteins that promote viral persistence and dysregulation of the immune system have an impact on immunopathogenesis of HCV-induced hepatitis. The genome of HCV encodes a single polyprotein, which is translated and processed into structural and nonstructural proteins. These HCV proteins are the target of the innate and adaptive immune system of the host. Retinoic acid-inducible gene-I (RIG-I)-like receptors and Toll-like receptors are the main pattern recognition receptors that recognize HCV pathogen-associated molecular patterns. This interaction results in a downstream cascade that generates antiviral cytokines including interferons. The cytolysis of HCV-infected hepatocytes is mediated by perforin and granzyme B secreted by cytotoxic T lymphocyte (CTL) and natural killer (NK) cells, whereas noncytolytic HCV clearance is mediated by interferon gamma (IFN-γ) secreted by CTL and NK cells. A host-HCV interaction determines whether the acute phase of an HCV infection will undergo complete resolution or progress to the development of viral persistence with a consequential progression to chronic HCV infection. Furthermore, these host-HCV interactions could pose a challenge to developing an HCV vaccine. This review will focus on the role of the innate and adaptive immunity in HCV infection, the failure of the immune response to clear an HCV infection, and the factors that promote viral persistence.
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Affiliation(s)
- DeGaulle I Chigbu
- Department of Microbiology and Immunology, and the Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 2900 West Queen Lane, Philadelphia, PA 19129, USA.
- Pennsylvania College of Optometry at Salus University, Elkins Park, PA 19027, USA.
| | - Ronak Loonawat
- Department of Microbiology and Immunology, and the Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 2900 West Queen Lane, Philadelphia, PA 19129, USA.
| | - Mohit Sehgal
- Immunology, Microenvironment & Metastasis Program, The Wistar Institute, Philadelphia, PA 19104, USA.
| | - Dip Patel
- Department of Microbiology and Immunology, and the Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 2900 West Queen Lane, Philadelphia, PA 19129, USA.
| | - Pooja Jain
- Department of Microbiology and Immunology, and the Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 2900 West Queen Lane, Philadelphia, PA 19129, USA.
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31
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Prentoe J, Bukh J. Hypervariable Region 1 in Envelope Protein 2 of Hepatitis C Virus: A Linchpin in Neutralizing Antibody Evasion and Viral Entry. Front Immunol 2018; 9:2146. [PMID: 30319614 PMCID: PMC6170631 DOI: 10.3389/fimmu.2018.02146] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 08/30/2018] [Indexed: 12/15/2022] Open
Abstract
Chronic hepatitis C virus (HCV) infection is the cause of about 400,000 annual liver disease-related deaths. The global spread of this important human pathogen can potentially be prevented through the development of a vaccine, but this challenge has proven difficult, and much remains unknown about the multitude of mechanisms by which this heterogeneous RNA virus evades inactivation by neutralizing antibodies (NAbs). The N-terminal motif of envelope protein 2 (E2), termed hypervariable region 1 (HVR1), changes rapidly in immunoglobulin-competent patients due to antibody-driven antigenic drift. HVR1 contains NAb epitopes and is directly involved in protecting diverse antibody-specific epitopes on E1, E2, and E1/E2 through incompletely understood mechanisms. The ability of HVR1 to protect HCV from NAbs appears linked with modulation of HCV entry co-receptor interactions. Thus, removal of HVR1 increases interaction with CD81, while altering interaction with scavenger receptor class B, type I (SR-BI) in a complex fashion, and decreasing interaction with low-density lipoprotein receptor. Despite intensive efforts this modulation of receptor interactions by HVR1 remains incompletely understood. SR-BI has received the most attention and it appears that HVR1 is involved in a multimodal HCV/SR-BI interaction involving high-density-lipoprotein associated ApoCI, which may prime the virus for later entry events by exposing conserved NAb epitopes, like those in the CD81 binding site. To fully elucidate the multifunctional role of HVR1 in HCV entry and NAb evasion, improved E1/E2 models and comparative studies with other NAb evasion strategies are needed. Derived knowledge may be instrumental in the development of a prophylactic HCV vaccine.
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Affiliation(s)
- Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, Copenhagen, Denmark.,Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, Copenhagen, Denmark.,Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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32
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Yost SA, Wang Y, Marcotrigiano J. Hepatitis C Virus Envelope Glycoproteins: A Balancing Act of Order and Disorder. Front Immunol 2018; 9:1917. [PMID: 30197646 PMCID: PMC6117417 DOI: 10.3389/fimmu.2018.01917] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Accepted: 08/02/2018] [Indexed: 12/16/2022] Open
Abstract
Chronic hepatitis C virus infection often leads to liver cirrhosis and primary liver cancer. In 2015, an estimated 71 million people were living with chronic HCV. Although infection rates have decreased in many parts of the world over the last several decades, incidence of HCV infection doubled between 2010 and 2014 in the United States mainly due to increases in intravenous drug use. The approval of direct acting antiviral treatments is a necessary component in the elimination of HCV, but inherent barriers to treatment (e.g., cost, lack of access to healthcare, adherence to treatment, resistance, etc.) prevent dramatic improvements in infection rates. An effective HCV vaccine would significantly slow the spread of the disease. Difficulties in the development of an HCV culture model system and expression of properly folded- and natively modified-HCV envelope glycoproteins E1 and E2 have hindered vaccine development efforts. The recent structural and biophysical studies of these proteins have demonstrated that the binding sites for the cellular receptor CD-81 and neutralizing antibodies are highly flexible in nature, which complicate vaccine design. Furthermore, the interactions between E1 and E2 throughout HCV infection is poorly understood, and structural flexibility may play a role in shielding antigenic epitopes during infection. Here we discuss the structural complexities of HCV E1 and E2.
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Affiliation(s)
- Samantha A Yost
- Department of Chemistry and Chemical Biology, Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ, United States
| | - Yuanyuan Wang
- Department of Chemistry and Chemical Biology, Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ, United States.,Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Joseph Marcotrigiano
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
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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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Tzarum N, Wilson IA, Law M. The Neutralizing Face of Hepatitis C Virus E2 Envelope Glycoprotein. Front Immunol 2018; 9:1315. [PMID: 29951061 PMCID: PMC6008530 DOI: 10.3389/fimmu.2018.01315] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/28/2018] [Indexed: 12/22/2022] Open
Abstract
The high genetic variability of hepatitis C virus, together with the high level of glycosylation on the viral envelope proteins shielding potential neutralizing epitopes, pose a difficult challenge for vaccine development. An effective hepatitis C virus (HCV) vaccine must target conserved epitopes and the HCV E2 glycoprotein is the main target for such neutralizing antibodies (NAbs). Recent structural investigations highlight the presence of a highly conserved and accessible surface on E2 that is devoid of N-linked glycans and known as the E2 neutralizing face. This face is defined as a hydrophobic surface comprising the front layer (FL) and the CD81 binding loop (CD81bl) that overlap with the CD81 receptor binding site on E2. The neutralizing face consists of highly conserved residues for recognition by cross-NAbs, yet it appears to be high conformationally flexible, thereby presenting a moving target for NAbs. Three main overlapping neutralizing sites have been identified in the neutralizing face: antigenic site 412 (AS412), antigenic site 434 (AS434), and antigenic region 3 (AR3). Here, we review the structural analyses of these neutralizing sites, either as recombinant E2 or epitope-derived linear peptides in complex with bNAbs, to understand the functional and preferred conformations for neutralization, and for viral escape. Collectively, these studies provide a foundation and molecular templates to facilitate structure-based approaches for HCV vaccine development.
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Affiliation(s)
- Netanel Tzarum
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, United States
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, United States.,Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA, United States
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, United States
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35
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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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36
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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: 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: 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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37
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Abstract
Current evidence supports a protective role for virus-neutralizing antibodies in immunity against hepatitis C virus (HCV) infection. Many cross-neutralizing monoclonal antibodies have been identified. These antibodies have been shown to provide protection or to clear infection in animal models. Previous clinical trials have shown that a gpE1/gpE2 vaccine can induce antibodies that neutralize the in vitro infectivity of all the major cell culture-derived HCV (HCVcc) genotypes around the world. However, cross-neutralization appeared to favor certain genotypes, with significant but lower neutralization against others. HCV may employ epitope masking to avoid antibody-mediated neutralization. Hypervariable region 1 (HVR1) at the amino terminus of glycoprotein E2 has been shown to restrict access to many neutralizing antibodies. Consistent with this, other groups have reported that recombinant viruses lacking HVR1 are hypersensitive to neutralization. It has been proposed that gpE1/gpE2 lacking this domain could be a better vaccine antigen to induce broadly neutralizing antibodies. In this study, we examined the immunogenicity of recombinant gpE1/gpE2 lacking HVR1 (ΔHVR1). Our results indicate that wild-type (WT) and ΔHVR1 gpE1/gpE2 antigens induced antibodies targeting many well-characterized cross-genotype-neutralizing epitopes. However, while the WT gpE1/gpE2 vaccine can induce cross-genotype protection against various genotypes of HCVcc and/or HCV-pseudotyped virus (HCVpp), antisera from ΔHVR1 gpE1/gpE2-immunized animals exhibited either reduced homologous neutralization activity compared to that of the WT or heterologous neutralization activity similar to that of the WT. These data suggest that ΔHVR1 gpE1/gpE2 is not a superior vaccine antigen. Based on previously reported chimpanzee protection data using WT gpE1/gpE2 and our current findings, we are preparing a combination vaccine including wild-type recombinant gpE1/gpE2 for clinical testing in the future. IMPORTANCE An HCV vaccine is an unmet medical need. Current evidence suggests that neutralizing antibodies play an important role in virus clearance, along with cellular immune responses. Previous clinical data showed that gpE1/gpE2 can effectively induce cross-neutralizing antibodies, although they favor certain genotypes. HCV employs HVR1 within gpE2 to evade host immune control. It has been hypothesized that the removal of this domain would improve the production of cross-neutralizing antibodies. In this study, we compared the immunogenicities of WT and ΔHVR1 gpE1/gpE2 antigens as vaccine candidates. Our results indicate that the ΔHVR1 gpE1/gpE2 antigen confers no advantages in the neutralization of HCV compared with the WT antigen. Previously, we showed that this WT antigen remains the only vaccine candidate to protect chimpanzees from chronic infection, contains multiple cross-neutralizing epitopes, and is well tolerated and immunogenic in humans. The current data support the further clinical development of this vaccine antigen component.
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Balasco N, Barone D, Iaccarino E, Sandomenico A, De Simone A, Ruvo M, Vitagliano L. Intrinsic structural versatility of the highly conserved 412-423 epitope of the Hepatitis C Virus E2 protein. Int J Biol Macromol 2018; 116:620-632. [PMID: 29758309 DOI: 10.1016/j.ijbiomac.2018.05.055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 05/09/2018] [Accepted: 05/10/2018] [Indexed: 12/14/2022]
Abstract
HCV infection is a major threaten for human health as it affects hundreds of million people worldwide. Here we investigated the conformational properties of the 412-423 fragment of the envelope E2 protein, one of the most immunogenic regions of the virus proteome whose characterization may provide interesting insights for anti-HCV vaccine development. The spectroscopic characterization of the polypeptide unravels its unexpected tendency to form amyloid-like aggregates. When kept in monomeric state, it shows a limited tendency to adopt regular secondary structure. Enhanced molecular dynamics simulations, starting from four distinct conformational states, highlight its structural versatility. Interestingly, all multiform conformational states of the polypeptide detected in crystallographic complexes with antibodies are present in the structural ensemble of all simulations. This observation corroborates the idea that known antibodies recognize this region through a conformational selection mechanism. Accordingly, the design of effective anti-HCV vaccines should consider the intrinsic flexibility of this region. The structural versatility of the 412-423 region is particularly puzzling if its remarkable sequence conservation is considered. It is likely that flexibility and sequence conservation are important features that endow this epitope with the ability to accomplish distinct functions such as immunity escape and interaction with host receptors.
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Affiliation(s)
- Nicole Balasco
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy.
| | - Daniela Barone
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy; Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Caserta 81100, Italy
| | - Emanuela Iaccarino
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy; Dipartimento di Scienze e Tecnologie Ambientali Biologiche e Farmaceutiche, Università della Campania "Luigi Vanvitelli", Caserta 81100, Italy
| | | | - Alfonso De Simone
- Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Menotti Ruvo
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy
| | - Luigi Vitagliano
- Institute of Biostructures and Bioimaging, CNR, Naples I-80134, Italy.
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39
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Can Broadly Neutralizing Monoclonal Antibodies Lead to a Hepatitis C Virus Vaccine? Trends Microbiol 2018; 26:854-864. [PMID: 29703495 DOI: 10.1016/j.tim.2018.04.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/09/2018] [Accepted: 04/02/2018] [Indexed: 12/20/2022]
Abstract
While licensed vaccines elicit protective antibody responses against a variety of viral infections, an effective vaccine for hepatitis C virus (HCV) has remained elusive. The extraordinary genetic diversity of HCV and the ability of the virus to evade the immune response have hindered vaccine development efforts. However, recent studies have greatly expanded the number of well characterized broadly neutralizing human monoclonal antibodies (bNAbs) against HCV. These bNAbs target relatively conserved HCV epitopes, prevent HCV infection in animal models, and are associated with spontaneous clearance of human HCV infection. In this review, recent high-resolution bNAb epitope mapping and structural analysis of bNAb-epitope complexes that may serve as a guide for vaccine development are discussed along with major obstacles.
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Fuerst TR, Pierce BG, Keck ZY, Foung SKH. Designing a B Cell-Based Vaccine against a Highly Variable Hepatitis C Virus. Front Microbiol 2018; 8:2692. [PMID: 29379486 PMCID: PMC5775222 DOI: 10.3389/fmicb.2017.02692] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 12/26/2017] [Indexed: 02/06/2023] Open
Abstract
The ability to use structure-based design and engineering to control the molecular shape and reactivity of an immunogen to induce protective responses shows great promise, along with corresponding advancements in vaccine testing and evaluation systems. We describe in this review new paradigms for the development of a B cell-based HCV vaccine. Advances in test systems to measure in vitro and in vivo antibody-mediated virus neutralization include retroviral pseudotype particles expressing HCV E1E2 glycoproteins (HCVpp), infectious cell culture-derived HCV virions (HCVcc), and surrogate animal models mimicking acute HCV infection. Their applications have established the role of broadly neutralizing antibodies to control HCV infection. However, the virus has immunogenic regions in the viral envelope glycoproteins that are associated with viral escape or non-neutralizing antibodies. These regions serve as immunologic decoys that divert the antibody response from less prominent conserved regions mediating virus neutralization. This review outlines the immunogenic regions on E2, which are roughly segregated into the hypervariable region 1 (HVR1), and five clusters of overlapping epitopes designated as antigenic domains A-E. Understanding the molecular architecture of conserved neutralizing epitopes within these antigenic domains, and how other antigenic regions or decoys deflect the immune response from these conserved regions will provide a roadmap for the rational design of an HCV vaccine.
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Affiliation(s)
- Thomas R Fuerst
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, United States.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
| | - Brian G Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, United States.,Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
| | - Zhen-Yong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, United States
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, United States
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41
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Synergistic anti-HCV broadly neutralizing human monoclonal antibodies with independent mechanisms. Proc Natl Acad Sci U S A 2017; 115:E82-E91. [PMID: 29255018 DOI: 10.1073/pnas.1718441115] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
There is an urgent need for a vaccine to combat the hepatitis C virus (HCV) pandemic, and induction of broadly neutralizing monoclonal antibodies (bNAbs) against HCV is a major goal of vaccine development. Even within HCV genotype 1, no single bNAb effectively neutralizes all viral strains, so induction of multiple neutralizing monoclonal antibodies (NAbs) targeting distinct epitopes may be necessary for protective immunity. Therefore, identification of optimal NAb combinations and characterization of NAb interactions can guide vaccine development. We analyzed neutralization profiles of 12 human NAbs across diverse HCV strains, assigning the NAbs to two functionally distinct clusters. We then measured neutralizing breadth of 35 NAb combinations against genotype 1 isolates, with each combination including one NAb from each neutralization cluster. Many NAbs displayed complementary neutralizing breadth, forming combinations with greater neutralization across diverse strains than any individual bNAb. Remarkably, one of the most broadly neutralizing combinations of two NAbs, designated HEPC74/HEPC98, also displayed enhanced potency, with interactions matching the Bliss independence model, suggesting that these NAbs inhibit HCV infection through independent mechanisms. Subsequent experiments showed that HEPC74 primarily blocks HCV envelope protein binding to CD81, while HEPC98 primarily blocks binding to scavenger receptor B1 and heparan sulfate. Together, these data identify a critical vulnerability resulting from the reliance of HCV on multiple cell surface receptors, suggesting that vaccine induction of multiple NAbs with distinct neutralization profiles is likely to enhance the breadth and potency of the humoral immune response against HCV.
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42
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Desombere I, Mesalam AA, Urbanowicz RA, Van Houtte F, Verhoye L, Keck ZY, Farhoudi A, Vercauteren K, Weening KE, Baumert TF, Patel AH, Foung SKH, Ball J, Leroux-Roels G, Meuleman P. A novel neutralizing human monoclonal antibody broadly abrogates hepatitis C virus infection in vitro and in vivo. Antiviral Res 2017; 148:53-64. [PMID: 29074219 PMCID: PMC5785094 DOI: 10.1016/j.antiviral.2017.10.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 10/06/2017] [Accepted: 10/16/2017] [Indexed: 02/07/2023]
Abstract
Infections with hepatitis C virus (HCV) represent a worldwide health burden and a prophylactic vaccine is still not available. Liver transplantation (LT) is often the only option for patients with HCV-induced end-stage liver disease. However, immediately after transplantation, the liver graft becomes infected by circulating virus, resulting in accelerated progression of liver disease. Although the efficacy of HCV treatment using direct-acting antivirals has improved significantly, immune compromised LT-patients and patients with advanced liver disease remain difficult to treat. As an alternative approach, interfering with viral entry could prevent infection of the donor liver. We generated a human monoclonal antibody (mAb), designated 2A5, which targets the HCV envelope. The neutralizing activity of mAb 2A5 was assessed using multiple prototype and patient-derived HCV pseudoparticles (HCVpp), cell culture produced HCV (HCVcc), and a human-liver chimeric mouse model. Neutralization levels observed for mAb 2A5 were generally high and mostly superior to those obtained with AP33, a well-characterized HCV-neutralizing monoclonal antibody. Using humanized mice, complete protection was observed after genotype 1a and 4a HCV challenge, while only partial protection was achieved using gt1b and 6a isolates. Epitope mapping revealed that mAb 2A5 binding is conformation-dependent and identified the E2-region spanning amino acids 434 to 446 (epitope II) as the predominant contact domain. CONCLUSION mAb 2A5 shows potent anti-HCV neutralizing activity both in vitro and in vivo and could hence represent a valuable candidate to prevent HCV recurrence in LT-patients. In addition, the detailed identification of the neutralizing epitope can be applied for the design of prophylactic HCV vaccines.
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Affiliation(s)
- Isabelle Desombere
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium.
| | - Ahmed Atef Mesalam
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium; Therapeutic Chemistry Department, National Research Centre (NRC), Dokki, Cairo, Egypt.
| | - Richard A Urbanowicz
- School of Life Sciences, The University of Nottingham, Nottingham, NG7 2RD, UK; Nottingham Digestive Diseases Centre, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and The University of Nottingham, Nottingham, NG7 2UH, UK.
| | - Freya Van Houtte
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium.
| | - Lieven Verhoye
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium.
| | - Zhen-Yong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Ali Farhoudi
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium.
| | - Koen Vercauteren
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium.
| | - Karin E Weening
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium.
| | - Thomas F Baumert
- Inserm U1110, Institut de Recherche sur les Maladies Virales et Hépatiques, Strasbourg, France; Université de Strasbourg, Strasbourg et Pole Hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
| | - Arvind H Patel
- MRC-University of Glasgow Centre for Virus Research, University of Glasgow, Glasgow, UK.
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Jonathan Ball
- School of Life Sciences, The University of Nottingham, Nottingham, NG7 2RD, UK; Nottingham Digestive Diseases Centre, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and The University of Nottingham, Nottingham, NG7 2UH, UK.
| | - Geert Leroux-Roels
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium.
| | - Philip Meuleman
- Department of Clinical Chemistry, Microbiology and Immunology, Ghent University, Ghent, Belgium.
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43
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Akhras S, Toda M, Boller K, Himmelsbach K, Elgner F, Biehl M, Scheurer S, Gratz M, Vieths S, Hildt E. Cell-permeable capsids as universal antigen carrier for the induction of an antigen-specific CD8 + T-cell response. Sci Rep 2017; 7:9630. [PMID: 28851900 PMCID: PMC5575276 DOI: 10.1038/s41598-017-08787-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 07/13/2017] [Indexed: 01/21/2023] Open
Abstract
Vaccine platforms that can be flexibly loaded with antigens can contribute to decrease response time to emerging infections. For many pathogens and chronic infections, induction of a robust cytotoxic T lymphocytes-mediated response is desirable to control infection. Antigen delivery into the cytoplasm of antigen presenting cells favors induction of cytotoxic T cells. By fusion of the cell-permeable translocation motif (TLM)-peptide to the capsid-forming core protein of hepatitis B virus, and by insertion of the strep-tag in the spike tip (a domain that protrudes from the surface of the capsid), cell-permeable carrier capsids were generated that can be flexibly loaded with various antigens. Loading with antigens was demonstrated by electron microscopy, density gradient centrifugation and surface plasmon resonance spectroscopy. Confocal immunofluorescence microscopy showed that cell-permeable carrier capsids mediate transfer of cargo antigen into the cytoplasm. Using cell-permeable carrier capsids loaded with ovalbumin as model antigen, activation of antigen presenting cells and ovalbumin-specific CD8+ T-cells, which correlates with enhanced specific killing activity, was found. This demonstrates the capacity of TLM-carrier-capsids to serve as universal antigen carrier to deliver antigens into the cytoplasm of antigen presenting cells, which leads to enhanced MHC class I-mediated presentation and induction of antigen-specific cytotoxic T lymphocytes response.
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Affiliation(s)
- Sami Akhras
- Department of Virology, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Masako Toda
- Department of Allergology, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Klaus Boller
- Department of Immunology, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | | | - Fabian Elgner
- Department of Virology, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Marlene Biehl
- Department of Virology, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Stephan Scheurer
- Department of Allergology, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Meike Gratz
- Department of Virology, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Stefan Vieths
- Department of Allergology, Paul-Ehrlich-Institut, 63225, Langen, Germany
| | - Eberhard Hildt
- Department of Virology, Paul-Ehrlich-Institut, 63225, Langen, Germany. .,German Center for Infection Research (DZIF), 38124, Braunschweig, Germany.
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44
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Vasiliauskaite I, Owsianka A, England P, Khan AG, Cole S, Bankwitz D, Foung SKH, Pietschmann T, Marcotrigiano J, Rey FA, Patel AH, Krey T. Conformational Flexibility in the Immunoglobulin-Like Domain of the Hepatitis C Virus Glycoprotein E2. mBio 2017; 8:e00382-17. [PMID: 28512091 PMCID: PMC5433095 DOI: 10.1128/mbio.00382-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 04/24/2017] [Indexed: 12/16/2022] Open
Abstract
The hepatitis C virus (HCV) glycoprotein E2 is the major target of neutralizing antibodies and is therefore highly relevant for vaccine design. Its structure features a central immunoglobulin (Ig)-like β-sandwich that contributes to the binding site for the cellular receptor CD81. We show that a synthetic peptide corresponding to a β-strand of this Ig-like domain forms an α-helix in complex with the anti-E2 antibody DAO5, demonstrating an inside-out flip of hydrophobic residues and a secondary structure change in the composite CD81 binding site. A detailed interaction analysis of DAO5 and cross-competing neutralizing antibodies with soluble E2 revealed that the Ig-like domain is trapped by different antibodies in at least two distinct conformations. DAO5 specifically captures retrovirus particles bearing HCV glycoproteins (HCVpp) and infectious cell culture-derived HCV particles (HCVcc). Infection of cells by DAO5-captured HCVpp can be blocked by a cross-competing neutralizing antibody, indicating that a single virus particle simultaneously displays E2 molecules in more than one conformation on its surface. Such conformational plasticity of the HCV E2 receptor binding site has important implications for immunogen design.IMPORTANCE Recent advances in the treatment of hepatitis C virus (HCV) infection with direct-acting antiviral drugs have enabled the control of this major human pathogen. However, due to their high costs and limited accessibility in combination with the lack of awareness of the mostly asymptomatic infection, there is an unchanged urgent need for an effective vaccine. The viral glycoprotein E2 contains regions that are crucial for virus entry into the host cell, and antibodies that bind to these regions can neutralize infection. One of the major targets of neutralizing antibodies is the central immunoglobulin (Ig)-like domain within E2. We show here that this Ig-like domain is conformationally flexible at the surface of infectious HCV particles and pseudoparticles. Our study provides novel insights into the interactions of HCV E2 with the humoral immune system that should aid future vaccine development.
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Affiliation(s)
- Ieva Vasiliauskaite
- Unité de Virologie Structurale, Department Virologie, Institut Pasteur, Paris, France
- CNRS UMR 3569, Paris, France
| | - Ania Owsianka
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Patrick England
- Plate-Forme de Biophysique Moléculaire, Institut Pasteur, Paris, France
- CNRS UMR 3528, Paris, France
| | - Abdul Ghafoor Khan
- Center for Advanced Biotechnology and Medicine, Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Sarah Cole
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Dorothea Bankwitz
- Institute for Experimental Virology, Centre for Experimental and Clinical Infection Research, Twincore, Hannover, Germany
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Thomas Pietschmann
- Institute for Experimental Virology, Centre for Experimental and Clinical Infection Research, Twincore, Hannover, Germany
- German Center for Infection Research, Hannover-Braunschweig Site, Germany
| | - Joseph Marcotrigiano
- Center for Advanced Biotechnology and Medicine, Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, USA
| | - Felix A Rey
- Unité de Virologie Structurale, Department Virologie, Institut Pasteur, Paris, France
- CNRS UMR 3569, Paris, France
| | - Arvind H Patel
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Thomas Krey
- Unité de Virologie Structurale, Department Virologie, Institut Pasteur, Paris, France
- CNRS UMR 3569, Paris, France
- Institute of Virology, Hannover Medical School, Hannover, Germany
- German Center for Infection Research, Hannover-Braunschweig Site, Germany
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45
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El-Diwany R, Cohen VJ, Mankowski MC, Wasilewski LN, Brady JK, Snider AE, Osburn WO, Murrell B, Ray SC, Bailey JR. Extra-epitopic hepatitis C virus polymorphisms confer resistance to broadly neutralizing antibodies by modulating binding to scavenger receptor B1. PLoS Pathog 2017; 13:e1006235. [PMID: 28235087 PMCID: PMC5342271 DOI: 10.1371/journal.ppat.1006235] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 03/08/2017] [Accepted: 02/11/2017] [Indexed: 12/15/2022] Open
Abstract
Broadly-neutralizing monoclonal antibodies (bNAbs) may guide vaccine development for highly variable viruses including hepatitis C virus (HCV), since they target conserved viral epitopes that could serve as vaccine antigens. However, HCV resistance to bNAbs could reduce the efficacy of a vaccine. HC33.4 and AR4A are two of the most potent anti-HCV human bNAbs characterized to date, binding to highly conserved epitopes near the amino- and carboxy-terminus of HCV envelope (E2) protein, respectively. Given their distinct epitopes, it was surprising that these bNAbs showed similar neutralization profiles across a panel of natural HCV isolates, suggesting that some viral polymorphisms may confer resistance to both bNAbs. To investigate this resistance, we developed a large, diverse panel of natural HCV envelope variants and a novel computational method to identify bNAb resistance polymorphisms in envelope proteins (E1 and E2). By measuring neutralization of a panel of HCV pseudoparticles by 10 μg/mL of each bNAb, we identified E1E2 variants with resistance to one or both bNAbs, despite 100% conservation of the AR4A binding epitope across the panel. We discovered polymorphisms outside of either binding epitope that modulate resistance to both bNAbs by altering E2 binding to the HCV co-receptor, scavenger receptor B1 (SR-B1). This study is focused on a mode of neutralization escape not addressed by conventional analysis of epitope conservation, highlighting the contribution of extra-epitopic polymorphisms to bNAb resistance and presenting a novel mechanism by which HCV might persist even in the face of an antibody response targeting multiple conserved epitopes. Generation of an immune response that is protective against a wide variety of naturally occurring isolates is necessary for vaccines against highly variable viruses like hepatitis C virus (HCV). Two broadly neutralizing human monoclonal antibodies, HC33.4 and AR4A, neutralize multiple highly divergent HCV isolates, raising hope that a vaccine against HCV is possible. Previous reports have defined the distinct, highly conserved sites on the viral envelope proteins where these antibodies bind. However, little is known about naturally occurring variation in sensitivity of different HCV isolates to these antibodies. We developed a high throughput assay and computational algorithm to evaluate over 100 naturally occurring HCV variants for their sensitivity to these two antibodies, identifying several resistance polymorphisms to each antibody which do not fall within their mapped binding sites. Furthermore, two of these polymorphisms modulate resistance to both antibodies by enhancing or reducing envelope protein binding to HCV co-receptor scavenger receptor B1 (SR-B1). By developing this broadly applicable platform, we have shown the important neutralization resistance conferred by changes distant from antibody binding sites, presenting a potential mechanism by which HCV might persist even in the face of an antibody response targeting multiple conserved sites.
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Affiliation(s)
- Ramy El-Diwany
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Valerie J. Cohen
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Madeleine C. Mankowski
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Lisa N. Wasilewski
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Jillian K. Brady
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Anna E. Snider
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - William O. Osburn
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Ben Murrell
- Department of Medicine, University of California, San Diego, La Jolla, California, United States of America
| | - Stuart C. Ray
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Justin R. Bailey
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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46
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An Optimized Hepatitis C Virus E2 Glycoprotein Core Adopts a Functional Homodimer That Efficiently Blocks Virus Entry. J Virol 2017; 91:JVI.01668-16. [PMID: 28031364 DOI: 10.1128/jvi.01668-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Indexed: 12/25/2022] Open
Abstract
The hepatitis C virus (HCV) envelope glycoprotein E2 is the major target of broadly neutralizing antibodies in vivo and is the focus of efforts in the rational design of a universal B cell vaccine against HCV. The E2 glycoprotein exhibits a high degree of amino acid variability which localizes to three discrete regions: hypervariable region 1 (HVR1), hypervariable region 2 (HVR2), and the intergenotypic variable region (igVR). All three variable regions contribute to immune evasion and/or isolate-specific structural variations, both important considerations for vaccine design. A high-resolution structural definition of the intact HCV envelope glycoprotein complex containing E1 and E2 remains to be elucidated, while crystallographic structures of a recombinant E2 ectodomain failed to resolve HVR1, HVR2, and a major neutralization determinant adjacent to HVR1. To obtain further information on E2, we characterized the role of all three variable regions in E2 ectodomain folding and function in the context of a recombinant ectodomain fragment (rE2). We report that removal of the variable regions accelerates binding to the major host cell receptor CD81 and that simultaneous deletion of HVR2 and the igVR is required to maintain wild-type CD81-binding characteristics. The removal of the variable regions also rescued the ability of rE2 to form a functional homodimer. We propose that the rE2 core provides novel insights into the role of the variable motifs in the higher-order assembly of the E2 ectodomain and may have implications for E1E2 structure on the virion surface. IMPORTANCE Hepatitis C virus (HCV) infection affects ∼2% of the population globally, and no vaccine is available. HCV is a highly variable virus, and understanding the presentation of key antigenic sites at the virion surface is important for the design of a universal vaccine. This study investigates the role of three surface-exposed variable regions in E2 glycoprotein folding and function in the context of a recombinant soluble ectodomain. Our data demonstrate the variable motifs modulate binding of the E2 ectodomain to the major host cell receptor CD81 and have an impact on the formation of an E2 homodimer with high-affinity binding to CD81.
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47
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Bankwitz D, Pietschmann T. Hepatitis C virus plays hide and seek with neutralizing antibodies. Hepatology 2016; 64:1840-1842. [PMID: 27515101 DOI: 10.1002/hep.28760] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 08/05/2016] [Accepted: 08/08/2016] [Indexed: 12/20/2022]
Affiliation(s)
- Dorothea Bankwitz
- Institute of Experimental Virology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany
| | - Thomas Pietschmann
- Institute of Experimental Virology, TWINCORE Centre for Experimental and Clinical Infection Research, Hannover, Germany.,German Centre for Infection Research, Hannover-Braunschweig, Germany
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Prentoe J, Velázquez-Moctezuma R, Foung SKH, Law M, Bukh J. Hypervariable region 1 shielding of hepatitis C virus is a main contributor to genotypic differences in neutralization sensitivity. Hepatology 2016; 64:1881-1892. [PMID: 27351277 PMCID: PMC5115964 DOI: 10.1002/hep.28705] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 06/15/2016] [Indexed: 12/11/2022]
Abstract
UNLABELLED There are 3-4 million new hepatitis C virus (HCV) infections yearly. The extensive intergenotypic sequence diversity of envelope proteins E1 and E2 of HCV and shielding of important epitopes by hypervariable region 1 (HVR1) of E2 are believed to be major hindrances to developing universally protective HCV vaccines. Using cultured viruses expressing the E1/E2 complex of isolates H77 (genotype 1a), J6 (2a), or S52 (3a), with and without HVR1, we tested HVR1-mediated neutralization occlusion in vitro against a panel of 12 well-characterized human monoclonal antibodies (HMAbs) targeting diverse E1, E2, and E1/E2 epitopes. Surprisingly, HVR1-mediated protection was greatest for S52, followed by J6 and then H77. HCV pulldown experiments showed that this phenomenon was caused by epitope shielding. Moreover, by regression analysis of HMAb binding and neutralization titer of HCV we found a strong correlation for HVR1-deleted viruses but not for parental viruses retaining HVR1. The intergenotype neutralization sensitivity of the parental viruses to HMAb antigenic region (AR) 2A, AR3A, AR4A, AR5A, HC84.26, and HC33.4 varied greatly (>24-fold to >130-fold differences in 50% inhibitory concentration values). However, except for AR5A, these differences decreased to less than 6.0-fold when comparing the corresponding HVR1-deleted viruses. Importantly, this simplified pattern of neutralization sensitivity in the absence of HVR1 was also demonstrated in a panel of HVR1-deleted viruses of genotypes 1a, 2a, 2b, 3a, 5a, and 6a, although for all HMAbs, except AR4A, an outlier was observed. Finally, unique amino acid residues in HCV E2 could explain these outliers in the tested cases of AR5A and HC84.26. CONCLUSION HVR1 adds complexity to HCV neutralization by shielding a diverse array of unexpectedly cross-genotype-conserved E1/E2 epitopes. Thus, an HVR1-deleted antigen could be a better HCV vaccine immunogen. (Hepatology 2016;64:1881-1892).
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Affiliation(s)
- Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark,Corresponding authors Dr. Jannick Prentoe, Ph.D. and Prof. Jens Bukh, M.D., Department of Infectious Diseases #144, Copenhagen University Hospital, Kettegaard Allé 30, DK-2650 Hvidovre, Denmark. ;
| | - Rodrigo Velázquez-Moctezuma
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Steven K. H. Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Mansun Law
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark,Corresponding authors Dr. Jannick Prentoe, Ph.D. and Prof. Jens Bukh, M.D., Department of Infectious Diseases #144, Copenhagen University Hospital, Kettegaard Allé 30, DK-2650 Hvidovre, Denmark. ;
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Freedman H, Logan MR, Law JLM, Houghton M. Structure and Function of the Hepatitis C Virus Envelope Glycoproteins E1 and E2: Antiviral and Vaccine Targets. ACS Infect Dis 2016; 2:749-762. [PMID: 27933781 DOI: 10.1021/acsinfecdis.6b00110] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The hepatitis C virus (HCV) envelope glycoproteins E1 and E2 are critical in viral attachment and cell fusion, and studies of these proteins may provide valuable insights into their potential uses in vaccines and antiviral strategies. Progress has included elucidating the crystal structures of portions of their ectodomains, as well as many other studies of hypervariable regions, stem regions, glycosylation sites, and the participation of E1/E2 in viral fusion with the endosomal membrane. The available structural data have shed light on the binding sites of cross-neutralizing antibodies. A large amount of information has been discovered concerning heterodimerization, including the roles of transmembrane domains, disulfide bonding, and heptad repeat regions. The possible organization of higher order oligomers within the HCV virion has also been evaluated on the basis of experimental data. In this review, E1/E2 structure and function is discussed, and some important issues requiring further study are highlighted.
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Affiliation(s)
- Holly Freedman
- Li Ka Shing Institute of Virology, Department of Medical Microbiology
and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Michael R. Logan
- Li Ka Shing Institute of Virology, Department of Medical Microbiology
and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - John Lok Man Law
- Li Ka Shing Institute of Virology, Department of Medical Microbiology
and Immunology, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Houghton
- Li Ka Shing Institute of Virology, Department of Medical Microbiology
and Immunology, University of Alberta, Edmonton, Alberta, Canada
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Global mapping of antibody recognition of the hepatitis C virus E2 glycoprotein: Implications for vaccine design. Proc Natl Acad Sci U S A 2016; 113:E6946-E6954. [PMID: 27791171 DOI: 10.1073/pnas.1614942113] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The E2 envelope glycoprotein is the primary target of human neutralizing antibody response against hepatitis C virus (HCV), and is thus a major focus of vaccine and immunotherapeutics efforts. There is emerging evidence that E2 is a highly complex, dynamic protein with residues across the protein that are modulating antibody recognition, local and global E2 stability, and viral escape. To comprehensively map these determinants, we performed global E2 alanine scanning with a panel of 16 human monoclonal antibodies (hmAbs), resulting in an unprecedented dataset of the effects of individual alanine substitutions across the E2 protein (355 positions) on antibody recognition. Analysis of shared energetic effects across the antibody panel identified networks of E2 residues involved in antibody recognition and local and global E2 stability, as well as predicted contacts between residues across the entire E2 protein. Further analysis of antibody binding hotspot residues defined groups of residues essential for E2 conformation and recognition for all 14 conformationally dependent E2 antibodies and subsets thereof, as well as residues that enhance antibody recognition when mutated to alanine, providing a potential route to engineer E2 vaccine immunogens. By incorporating E2 sequence variability, we found a number of E2 polymorphic sites that are responsible for loss of neutralizing antibody binding. These data and analyses provide fundamental insights into antibody recognition of E2, highlighting the dynamic and complex nature of this viral envelope glycoprotein, and can serve as a reference for development and rational design of E2-targeting vaccines and immunotherapeutics.
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