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Pierce BG, Felbinger N, Metcalf M, Toth EA, Ofek G, Fuerst TR. Hepatitis C Virus E1E2 Structure, Diversity, and Implications for Vaccine Development. Viruses 2024; 16:803. [PMID: 38793684 PMCID: PMC11125608 DOI: 10.3390/v16050803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/02/2024] [Accepted: 05/15/2024] [Indexed: 05/26/2024] Open
Abstract
Hepatitis C virus (HCV) is a major medical health burden and the leading cause of chronic liver disease and cancer worldwide. More than 58 million people are chronically infected with HCV, with 1.5 million new infections occurring each year. An effective HCV vaccine is a major public health and medical need as recognized by the World Health Organization. However, due to the high variability of the virus and its ability to escape the immune response, HCV rapidly accumulates mutations, making vaccine development a formidable challenge. An effective vaccine must elicit broadly neutralizing antibodies (bnAbs) in a consistent fashion. After decades of studies from basic research through clinical development, the antigen of choice is considered the E1E2 envelope glycoprotein due to conserved, broadly neutralizing antigenic domains located in the constituent subunits of E1, E2, and the E1E2 heterodimeric complex itself. The challenge has been elicitation of robust humoral and cellular responses leading to broad virus neutralization due to the relatively low immunogenicity of this antigen. In view of this challenge, structure-based vaccine design approaches to stabilize key antigenic domains have been hampered due to the lack of E1E2 atomic-level resolution structures to guide them. Another challenge has been the development of a delivery platform in which a multivalent form of the antigen can be presented in order to elicit a more robust anti-HCV immune response. Recent nanoparticle vaccines are gaining prominence in the field due to their ability to facilitate a controlled multivalent presentation and trafficking to lymph nodes, where they can interact with both the cellular and humoral components of the immune system. This review focuses on recent advances in understanding the E1E2 heterodimeric structure to facilitate a rational design approach and the potential for development of a multivalent nanoparticle-based HCV E1E2 vaccine. Both aspects are considered important in the development of an effective HCV vaccine that can effectively address viral diversity and escape.
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Affiliation(s)
- Brian G. Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Nathaniel Felbinger
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Matthew Metcalf
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Eric A. Toth
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
| | - Gilad Ofek
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Thomas R. Fuerst
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850, USA; (B.G.P.); (N.F.); (M.M.); (E.A.T.); (G.O.)
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD 20742, USA
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Poddar S, Roy R, Kar P. The conformational dynamics of Hepatitis C Virus E2 glycoprotein with the increasing number of N-glycosylation unraveled by molecular dynamics simulations. J Biomol Struct Dyn 2024:1-16. [PMID: 38393644 DOI: 10.1080/07391102.2024.2319679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 02/12/2024] [Indexed: 02/25/2024]
Abstract
The Hepatitis C Virus (HCV), responsible for causing hepatitis and a significant contributor to liver disorders, presents a challenge for treatment due to its high genetic variability. Despite efforts, there is still no effective medication available for this virus. One of the promising targets for drug development involves targeting glycoprotein E2. However, our understanding of the dynamic behavior of E2 and its associated glycans remains limited. In this study, we investigated the dynamic characteristics of E2 with varying degrees of glycosylation using all-atom molecular dynamics simulations. We also explored glycan's interactions with the protein and among themselves. An overall increase in correlation between the vital protein regions was observed with an increase in glycan number. The protein dynamics is followed by the analysis of glycan dynamics, where the flexibility of the individual glycans was analyzed in their free and bound state, which revealed a decrease in their fluctuation in some cases. Furthermore, we generated the free energy landscape of individual N-glycan linkages in both free and bound states and observed both increases and decreases in flexibility, which can be attributed to the formation and breakage of hydrogen bonds with amino acids. Finally, we found that for a high glycosylation system, glycans interact with glycoprotein and form hydrogen bonds among themselves. Moreover, the hydrogen bond profiles of a given glycan can vary when influenced by other glycans. In summary, our study provides valuable insights into the dynamics of the core region of HCV E2 glycoprotein and its associated glycans.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sayan Poddar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, India
| | - Rajarshi Roy
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, India
| | - Parimal Kar
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Indore, Madhya Pradesh, India
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Tabll AA, Sohrab SS, Ali AA, Petrovic A, Steiner Srdarevic S, Siber S, Glasnovic M, Smolic R, Smolic M. Future Prospects, Approaches, and the Government's Role in the Development of a Hepatitis C Virus Vaccine. Pathogens 2023; 13:38. [PMID: 38251345 PMCID: PMC10820710 DOI: 10.3390/pathogens13010038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/23/2024] Open
Abstract
Developing a safe and effective vaccine against the hepatitis C virus (HCV) remains a top priority for global health. Despite recent advances in antiviral therapies, the high cost and limited accessibility of these treatments impede their widespread application, particularly in resource-limited settings. Therefore, the development of the HCV vaccine remains a necessity. This review article analyzes the current technologies, future prospects, strategies, HCV genomic targets, and the governmental role in HCV vaccine development. We discuss the current epidemiological landscape of HCV infection and the potential of HCV structural and non-structural protein antigens as vaccine targets. In addition, the involvement of government agencies and policymakers in supporting and facilitating the development of HCV vaccines is emphasized. We explore how vaccine development regulatory channels and frameworks affect research goals, funding, and public health policy. The significance of international and public-private partnerships in accelerating the development of an HCV vaccine is examined. Finally, the future directions for developing an HCV vaccine are discussed. In conclusion, the review highlights the urgent need for a preventive vaccine to fight the global HCV disease and the significance of collaborative efforts between scientists, politicians, and public health organizations to reach this important public health goal.
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Affiliation(s)
- Ashraf A. Tabll
- Microbial Biotechnology Department, Biotechnology Research Institute, National Research Centre, Cairo 12622, Egypt
- Egypt Centre for Research and Regenerative Medicine (ECRRM), Cairo 11517, Egypt
| | - Sayed S. Sohrab
- Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
- Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Ahmed A. Ali
- Molecular Biology Department, Biotechnology Research Institute, National Research Centre, Cairo 12622, Egypt;
| | - Ana Petrovic
- Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia; (A.P.); (S.S.S.); (S.S.); (M.G.); (R.S.)
| | - Sabina Steiner Srdarevic
- Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia; (A.P.); (S.S.S.); (S.S.); (M.G.); (R.S.)
| | - Stjepan Siber
- Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia; (A.P.); (S.S.S.); (S.S.); (M.G.); (R.S.)
| | - Marija Glasnovic
- Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia; (A.P.); (S.S.S.); (S.S.); (M.G.); (R.S.)
| | - Robert Smolic
- Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia; (A.P.); (S.S.S.); (S.S.); (M.G.); (R.S.)
| | - Martina Smolic
- Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, 31000 Osijek, Croatia; (A.P.); (S.S.S.); (S.S.); (M.G.); (R.S.)
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Abstract
There are at least 21 families of enveloped viruses that infect mammals, and many contain members of high concern for global human health. All enveloped viruses have a dedicated fusion protein or fusion complex that enacts the critical genome-releasing membrane fusion event that is essential before viral replication within the host cell interior can begin. Because all enveloped viruses enter cells by fusion, it behooves us to know how viral fusion proteins function. Viral fusion proteins are also major targets of neutralizing antibodies, and hence they serve as key vaccine immunogens. Here we review current concepts about viral membrane fusion proteins focusing on how they are triggered, structural intermediates between pre- and postfusion forms, and their interplay with the lipid bilayers they engage. We also discuss cellular and therapeutic interventions that thwart virus-cell membrane fusion.
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Affiliation(s)
- Judith M White
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia, USA;
| | - Amanda E Ward
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
| | - Laura Odongo
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
| | - Lukas K Tamm
- Center for Membrane and Cell Physiology, University of Virginia, Charlottesville, Virginia, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
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Landry SJ, Mettu RR, Kolls JK, Aberle JH, Norton E, Zwezdaryk K, Robinson J. Structural Framework for Analysis of CD4+ T-Cell Epitope Dominance in Viral Fusion Proteins. Biochemistry 2023; 62:2517-2529. [PMID: 37554055 PMCID: PMC10483696 DOI: 10.1021/acs.biochem.3c00335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/31/2023] [Indexed: 08/10/2023]
Abstract
Antigen conformation shapes CD4+ T-cell specificity through mechanisms of antigen processing, and the consequences for immunity may rival those from conformational effects on antibody specificity. CD4+ T cells initiate and control immunity to pathogens and cancer and are at least partly responsible for immunopathology associated with infection, autoimmunity, and allergy. The primary trigger for CD4+ T-cell maturation is the presentation of an epitope peptide in the MHC class II antigen-presenting protein (MHCII), most commonly on an activated dendritic cell, and then the T-cell responses are recalled by subsequent presentations of the epitope peptide by the same or other antigen-presenting cells. Peptide presentation depends on the proteolytic fragmentation of the antigen in an endosomal/lysosomal compartment and concomitant loading of the fragments into the MHCII, a multistep mechanism called antigen processing and presentation. Although the role of peptide affinity for MHCII has been well studied, the role of proteolytic fragmentation has received less attention. In this Perspective, we will briefly summarize evidence that antigen resistance to unfolding and proteolytic fragmentation shapes the specificity of the CD4+ T-cell response to selected viral envelope proteins, identify several remarkable examples in which the immunodominant CD4+ epitopes most likely depend on the interaction of processing machinery with antigen conformation, and outline how knowledge of antigen conformation can inform future efforts to design vaccines.
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Affiliation(s)
- Samuel J. Landry
- Department
of Biochemistry and Molecular Biology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Ramgopal R. Mettu
- Department
of Computer Science, Tulane University, New Orleans, Louisiana 70118, United States
| | - Jay K. Kolls
- John
W. Deming Department of Internal Medicine, Center for Translational
Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Judith H. Aberle
- Center
for Virology, Medical University of Vienna, 1090 Vienna, Austria
| | - Elizabeth Norton
- Department
of Microbiology & Immunology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - Kevin Zwezdaryk
- Department
of Microbiology & Immunology, Tulane
University School of Medicine, New Orleans, Louisiana 70112, United States
| | - James Robinson
- Department
of Pediatrics, Tulane University School
of Medicine, New Orleans, Louisiana 70112, United States
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Oliver MR, Toon K, Lewis CB, Devlin S, Gifford RJ, Grove J. Structures of the Hepaci-, Pegi-, and Pestiviruses envelope proteins suggest a novel membrane fusion mechanism. PLoS Biol 2023; 21:e3002174. [PMID: 37432947 PMCID: PMC10335668 DOI: 10.1371/journal.pbio.3002174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 05/26/2023] [Indexed: 07/13/2023] Open
Abstract
Enveloped viruses encode specialised glycoproteins that mediate fusion of viral and host membranes. Discovery and understanding of the molecular mechanisms of fusion have been achieved through structural analyses of glycoproteins from many different viruses, and yet the fusion mechanisms of some viral genera remain unknown. We have employed systematic genome annotation and AlphaFold modelling to predict the structures of the E1E2 glycoproteins from 60 viral species in the Hepacivirus, Pegivirus, and Pestivirus genera. While the predicted structure of E2 varied widely, E1 exhibited a very consistent fold across genera, despite little or no similarity at the sequence level. Critically, the structure of E1 is unlike any other known viral glycoprotein. This suggests that the Hepaci-, Pegi-, and Pestiviruses may possess a common and novel membrane fusion mechanism. Comparison of E1E2 models from various species reveals recurrent features that are likely to be mechanistically important and sheds light on the evolution of membrane fusion in these viral genera. These findings provide new fundamental understanding of viral membrane fusion and are relevant to structure-guided vaccinology.
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Affiliation(s)
- Michael R. Oliver
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Kamilla Toon
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Charlotte B. Lewis
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Stephen Devlin
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Robert J. Gifford
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Joe Grove
- MRC-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
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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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