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Wolfisberg R, Thorselius CE, Salinas E, Elrod E, Trivedi S, Nielsen L, Fahnøe U, Kapoor A, Grakoui A, Rice CM, Bukh J, Holmbeck K, Scheel TKH. Neutralization and receptor use of infectious culture-derived rat hepacivirus as a model for HCV. Hepatology 2022; 76:1506-1519. [PMID: 35445423 PMCID: PMC9585093 DOI: 10.1002/hep.32535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/06/2022] [Accepted: 04/08/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND AIMS Lack of tractable immunocompetent animal models amenable to robust experimental challenge impedes vaccine efforts for HCV. Infection with rodent hepacivirus from Rattus norvegicus (RHV-rn1) in rats shares HCV-defining characteristics, including liver tropism, chronicity, and pathology. RHV in vitro cultivation would facilitate genetic studies on particle production, host factor interactions, and evaluation of antibody neutralization guiding HCV vaccine approaches. APPROACH AND RESULTS We report an infectious reverse genetic cell culture system for RHV-rn1 using highly permissive rat hepatoma cells and adaptive mutations in the E2, NS4B, and NS5A viral proteins. Cell culture-derived RHV-rn1 particles (RHVcc) share hallmark biophysical characteristics of HCV and are infectious in mice and rats. Culture adaptive mutations attenuated RHVcc in immunocompetent rats, and the mutations reverted following prolonged infection, but not in severe combined immunodeficiency (SCID) mice, suggesting that adaptive immune pressure is a primary driver of reversion. Accordingly, sera from RHVcc-infected SCID mice or the early acute phase of immunocompetent mice and rats were infectious in culture. We further established an in vitro RHVcc neutralization assay, and observed neutralizing activity of rat sera specifically from the chronic phase of infection. Finally, we found that scavenger receptor class B type I promoted RHV-rn1 entry in vitro and in vivo. CONCLUSIONS The RHV-rn1 infectious cell culture system enables studies of humoral immune responses against hepacivirus infection. Moreover, recapitulation of the entire RHV-rn1 infectious cycle in cell culture will facilitate reverse genetic studies and the exploration of tropism and virus-host interactions.
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Affiliation(s)
- Raphael Wolfisberg
- Copenhagen Hepatitis C ProgramDepartment of Infectious DiseasesHvidovre HospitalCopenhagenDenmark,Department of Immunology and MicrobiologyUniversity of CopenhagenCopenhagenDenmark
| | - Caroline E. Thorselius
- Copenhagen Hepatitis C ProgramDepartment of Infectious DiseasesHvidovre HospitalCopenhagenDenmark,Department of Immunology and MicrobiologyUniversity of CopenhagenCopenhagenDenmark
| | - Eduardo Salinas
- Emory Vaccine CenterDivision of Microbiology and ImmunologyYerkes Research Primate CenterEmory University School of MedicineAtlantaGeorgiaUSA,Division of Infectious DiseasesDepartment of MedicineEmory University School of MedicineAtlantaGeorgiaUSA
| | - Elizabeth Elrod
- Emory Vaccine CenterDivision of Microbiology and ImmunologyYerkes Research Primate CenterEmory University School of MedicineAtlantaGeorgiaUSA,Division of Infectious DiseasesDepartment of MedicineEmory University School of MedicineAtlantaGeorgiaUSA
| | - Sheetal Trivedi
- Center for Vaccines and ImmunityResearch Institute at Nationwide Children’s HospitalColumbusOhioUSA
| | - Louise Nielsen
- Copenhagen Hepatitis C ProgramDepartment of Infectious DiseasesHvidovre HospitalCopenhagenDenmark,Department of Immunology and MicrobiologyUniversity of CopenhagenCopenhagenDenmark
| | - Ulrik Fahnøe
- Copenhagen Hepatitis C ProgramDepartment of Infectious DiseasesHvidovre HospitalCopenhagenDenmark,Department of Immunology and MicrobiologyUniversity of CopenhagenCopenhagenDenmark
| | - Amit Kapoor
- Center for Vaccines and ImmunityResearch Institute at Nationwide Children’s HospitalColumbusOhioUSA
| | - Arash Grakoui
- Emory Vaccine CenterDivision of Microbiology and ImmunologyYerkes Research Primate CenterEmory University School of MedicineAtlantaGeorgiaUSA,Division of Infectious DiseasesDepartment of MedicineEmory University School of MedicineAtlantaGeorgiaUSA
| | - Charles M. Rice
- Laboratory of Virology and Infectious DiseaseThe Rockefeller UniversityNew YorkNew YorkUSA
| | - Jens Bukh
- Copenhagen Hepatitis C ProgramDepartment of Infectious DiseasesHvidovre HospitalCopenhagenDenmark,Department of Immunology and MicrobiologyUniversity of CopenhagenCopenhagenDenmark
| | - Kenn Holmbeck
- Copenhagen Hepatitis C ProgramDepartment of Infectious DiseasesHvidovre HospitalCopenhagenDenmark,Department of Immunology and MicrobiologyUniversity of CopenhagenCopenhagenDenmark
| | - Troels K. H. Scheel
- Copenhagen Hepatitis C ProgramDepartment of Infectious DiseasesHvidovre HospitalCopenhagenDenmark,Department of Immunology and MicrobiologyUniversity of CopenhagenCopenhagenDenmark,Laboratory of Virology and Infectious DiseaseThe Rockefeller UniversityNew YorkNew YorkUSA
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2
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Gömer A, Delarocque J, Puff C, Nocke MK, Reinecke B, Baumgärtner W, Cavalleri JMV, Feige K, Steinmann E, Todt D. Dose-Dependent Hepacivirus Infection Reveals Linkage between Infectious Dose and Immune Response. Microbiol Spectr 2022; 10:e0168622. [PMID: 35993785 PMCID: PMC9602444 DOI: 10.1128/spectrum.01686-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 08/03/2022] [Indexed: 12/31/2022] Open
Abstract
More than 70 million people worldwide are still infected with the hepatitis C virus 30 years after its discovery, underscoring the need for a vaccine. To develop an effective prophylactic vaccine, detailed knowledge of the correlates of protection and an immunocompetent surrogate model are needed. In this study, we describe the minimum dose required for robust equine hepacivirus (EqHV) infection in equids and examined how this relates to duration of infection, seroconversion, and transcriptomic responses. To investigate mechanisms of hepaciviral persistence, immune response, and immune-mediated pathology, we inoculated eight EqHV naive horses with doses ranging from 1-2 copies to 1.3 × 106 RNA copies per inoculation. We characterized infection kinetics, pathology, and transcriptomic responses via next generation sequencing. The minimal infectious dose of EqHV in horses was estimated at 13 RNA copies, whereas 6 to 7 copies were insufficient to cause infection. Peak viremia did not correlate with infectious dose, while seroconversion and duration of infection appeared to be affected. Notably, seroconversion was undetectable in the low-dose infections within the surveillance period (40 to 50 days). In addition, transcriptomic analysis revealed a nearly dose-dependent effect, with greater immune activation and inflammatory response observed in high-dose infections than in low-dose infections. Interestingly, inoculation with 6-7 copies of RNA that did not result in productive infection, but was associated with a strong immune response, similar to that observed in the high-dose infections. IMPORTANCE We demonstrate that the EqHV dose of infection plays an important role for inducing immune responses, possibly linked to early clearance in high-dose and prolonged viremia in low-dose infections. In particular, pathways associated with innate and adaptive immune responses, as well as inflammatory responses, were more strongly upregulated in high-dose infections than in lower doses. Hence, inoculation with low doses may enable EqHV to evade strong immune responses in the early phase and therefore promote robust, long-lasting infection.
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Affiliation(s)
- André Gömer
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
- Institute of Virology, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Julien Delarocque
- Clinic for Horses, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Christina Puff
- Department of Pathology, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Maximilian K. Nocke
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Birthe Reinecke
- Institute of Experimental Virology, TWINCORE Centre for Experimental and Clinical Infection Research, Hanover, Germany
| | - Wolfgang Baumgärtner
- Department of Pathology, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Jessika M. V. Cavalleri
- Clinical Section of Equine Internal Medicine, Department of Companion Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Karsten Feige
- Clinic for Horses, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Eike Steinmann
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
| | - Daniel Todt
- Department of Molecular and Medical Virology, Ruhr University Bochum, Bochum, Germany
- European Virus Bioinformatics Center (EVBC), Jena, Germany
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3
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Han J, Zhu L, Zhang J, Guo L, Sun X, Huang C, Xu K, Zhang Y, Li W, Zhou Q. Rational engineering of adeno-associated virus capsid enhances human hepatocyte tropism and reduces immunogenicity. Cell Prolif 2022; 55:e13339. [PMID: 36135100 DOI: 10.1111/cpr.13339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/25/2022] [Accepted: 08/31/2022] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES Gene therapy based on recombinant adeno-associated viral (rAAV) vectors has been proved to be clinically effective for genetic diseases. However, there are still some limitations, including possible safety concerns for high dose delivery and a decreasing number of target patients caused by the high prevalence of pre-existing neutralizing antibodies, hindering its application. Herein, we explored whether there was an engineering strategy that can obtain mutants with enhanced transduction efficiency coupled with reduced immunogenicity. METHODS We described a new strategy for AAV capsids engineering by combining alterations of N-linked glycosylation and the mutation of PLA2-like motif. With this combined strategy, we generated novel variants derived from AAV8 and AAVS3. RESULTS The variants mediated higher transduction efficiency in human liver carcinoma cell lines and human primary hepatocytes as well as other human tissue cell lines. Importantly, all the variants screened out showed lower sensitivity to neutralizing antibody in vitro and in vivo. Moreover, the in vivo antibody profiles of variants were different from their parental AAV capsids. CONCLUSIONS Our work proposed a new combined engineering strategy and engineered two liver-tropic AAVs. We also obtained several AAV variants with a higher transduction efficiency and lower sensitivity of neutralizing antibodies. By expanding the gene delivery toolbox, these variants may further facilitate the success of AAV gene therapy.
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Affiliation(s)
- Jiabao Han
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Liyu Zhu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jingwen Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.,College of Life Science, Nankai University, Tianjin, China
| | - Lu Guo
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China
| | - Xuehan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Cheng Huang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Kai Xu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.,Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Ying Zhang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.,Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China.,Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Qi Zhou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Institute for Stem Cell and Regenerative Medicine, Chinese Academy of Sciences, Beijing, China.,University of Chinese Academy of Sciences, Beijing, China.,Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
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4
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Gömer A, Brown RJP, Pfaender S, Deterding K, Reuter G, Orton R, Seitz S, Bock CT, Cavalleri JMV, Pietschmann T, Wedemeyer H, Steinmann E, Todt D. OUP accepted manuscript. Virus Evol 2022; 8:veac007. [PMID: 35242360 PMCID: PMC8887644 DOI: 10.1093/ve/veac007] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 01/28/2022] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
Even 30 years after the discovery of the hepatitis C virus (HCV) in humans there is still no vaccine available. Reasons for this include the high mutation rate of HCV, which allows the virus to escape immune recognition and the absence of an immunocompetent animal model for vaccine development. Phylogenetically distinct hepaciviruses (genus Hepacivirus, family Flaviviridae) have been isolated from diverse species, each with a narrow host range: the equine hepacivirus (EqHV) is the closest known relative of HCV. In this study, we used amplicon-based deep-sequencing to investigate the viral intra-host population composition of the genomic regions encoding the surface glycoproteins E1 and E2. Patterns of E1E2 substitutional evolution were compared in longitudinally sampled EqHV-positive sera of naturally and experimentally infected horses and HCV-positive patients. Intra-host virus diversity was higher in chronically than in acutely infected horses, a pattern which was similar in the HCV-infected patients. However, overall glycoprotein variability was higher in HCV compared to EqHV. Additionally, selection pressure in HCV populations was higher, especially within the N-terminal region of E2, corresponding to the hypervariable region 1 (HVR1) in HCV. An alignment of glycoprotein sequences from diverse hepaciviruses identified the HVR1 as a unique characteristic of HCV: hepaciviruses from non-human species lack this region. Together, these data indicate that EqHV infection of horses could represent a powerful surrogate animal model to gain insights into hepaciviral evolution and HCVs HVR1-mediated immune evasion strategy.
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Affiliation(s)
| | | | - Stephanie Pfaender
- Department for Molecular and Medical Virology, Ruhr University Bochum, Universitätsstr. 150, Bochum 44801, Germany
| | - Katja Deterding
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Carl-Neuberg-Straße 1, Hannover 30625, Germany
- German Center for Infectious Disease Research (DZIF), HepNet Study-House, Hannover 30625, Germany
| | - Gábor Reuter
- Department of Medical Microbiology and Immunology, Medical School, University of Pécs, Szigeti út 12., Pécs 7624, Hungary
| | | | - Stefan Seitz
- Department of Infectious Diseases, Molecular Virology, University of Heidelberg, Heidelberg 69120, Germany
| | - C- Thomas Bock
- Division of Viral Gastroenteritis and Hepatitis Pathogens and Enteroviruses, Department of Infectious Diseases, Robert Koch Institute, Berlin 13353, Germany
| | - Jessika M V Cavalleri
- Clinical Unit of Equine Internal Medicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, Vienna 1210, Austria
| | - Thomas Pietschmann
- Twincore, Centre for Experimental and Clinical Infection Research, Institute of Experimental Virology, Hannover 30625, Germany
- German Centre for Infection Research (DZIF), Partner Site Hannover-Braunschweig Site, Hannover 30625, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover 30625, Germany
| | - Heiner Wedemeyer
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Carl-Neuberg-Straße 1, Hannover 30625, Germany
- German Center for Infectious Disease Research (DZIF), HepNet Study-House, Hannover 30625, Germany
| | - Eike Steinmann
- Department for Molecular and Medical Virology, Ruhr University Bochum, Universitätsstr. 150, Bochum 44801, Germany
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5
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Gruszewska E, Grytczuk A, Chrostek L. Glycosylation in viral hepatitis. Biochim Biophys Acta Gen Subj 2021; 1865:129997. [PMID: 34474116 DOI: 10.1016/j.bbagen.2021.129997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 08/26/2021] [Accepted: 08/26/2021] [Indexed: 01/12/2023]
Abstract
BACKGROUND The interaction between hepatitis viruses and host cells is regulated by glycans exposed on the surfaces of human and viruses cells. As the biosynthesis and degradation of human glycoproteins take place at the highest level in the liver, the changes in glycosylation of serum proteins may potentially be useful in the diagnosis of liver pathology. On the other hand, specific alterations in viruses envelope glycans could cause large changes in the entry process of hepatitis viruses into a host cells. SCOPE OF REVIEW Unique alterations in glycosylation of specific proteins can be detected in HBV and HCV infected patients especially with confirmed fibrosis/cirrhosis. On the other hand, viral envelope proteins that bind to host cells are glycosylated. These glycosylated proteins play a key role in recognition, binding and penetration of the host cells. In this review we summarized the knowledge about significance of glycosylation for viral and host factors. MAJOR CONCLUSIONS Glycosylation changes in single serum glycoproteins are noticed in the sera of patients with viral hepatitis. However, a more specific biomarker for the diagnosis of chronic hepatitis than that of a single glycosylated molecule is systemic investigation of complete set of glycan structures (N-glycome). Glycans play important roles in the viral biology cycle especially as a connecting element with host receptors. GENERAL SIGNIFICANCE The interaction between virus glycoproteins and cellular receptors, which are also glycoproteins, determines the possibility of virus penetration into host cells. Therefore these glycans can be the targets for the developing of novel treatment strategies of viral hepatitis.
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Affiliation(s)
- Ewa Gruszewska
- Department of Biochemical Diagnostics, Medical University of Bialystok, Waszyngtona 15A, 15-269 Bialystok, Poland
| | - Agnieszka Grytczuk
- Department of Laboratory Diagnostics, University Clinical Hospital in Bialystok, Bialystok, Poland
| | - Lech Chrostek
- Department of Biochemical Diagnostics, Medical University of Bialystok, Waszyngtona 15A, 15-269 Bialystok, Poland.
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6
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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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7
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LeBlanc EV, Kim Y, Capicciotti CJ, Colpitts CC. Hepatitis C Virus Glycan-Dependent Interactions and the Potential for Novel Preventative Strategies. Pathogens 2021; 10:pathogens10060685. [PMID: 34205894 PMCID: PMC8230238 DOI: 10.3390/pathogens10060685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 12/15/2022] Open
Abstract
Chronic hepatitis C virus (HCV) infections continue to be a major contributor to liver disease worldwide. HCV treatment has become highly effective, yet there are still no vaccines or prophylactic strategies available to prevent infection and allow effective management of the global HCV burden. Glycan-dependent interactions are crucial to many aspects of the highly complex HCV entry process, and also modulate immune evasion. This review provides an overview of the roles of viral and cellular glycans in HCV infection and highlights glycan-focused advances in the development of entry inhibitors and vaccines to effectively prevent HCV infection.
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Affiliation(s)
- Emmanuelle V. LeBlanc
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON K7L 3N6, Canada; (E.V.L.); (Y.K.); (C.J.C.)
| | - Youjin Kim
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON K7L 3N6, Canada; (E.V.L.); (Y.K.); (C.J.C.)
| | - Chantelle J. Capicciotti
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON K7L 3N6, Canada; (E.V.L.); (Y.K.); (C.J.C.)
- Department of Chemistry, Queen’s University, Kingston, ON K7L 3N6, Canada
- Department of Surgery, Queen’s University, Kingston, ON K7L 3N6, Canada
| | - Che C. Colpitts
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, ON K7L 3N6, Canada; (E.V.L.); (Y.K.); (C.J.C.)
- Correspondence:
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8
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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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9
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Rossi G, Galosi L, Gavazza A, Cerquetella M, Mangiaterra S. Therapeutic approaches to coronavirus infection according to "One Health" concept. Res Vet Sci 2021; 136:81-88. [PMID: 33588098 PMCID: PMC7871813 DOI: 10.1016/j.rvsc.2021.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 02/03/2021] [Accepted: 02/06/2021] [Indexed: 12/16/2022]
Abstract
Coronaviridae constantly infect human and animals causing respiratory, gastroenteric or systemic diseases. Over time, these viruses have shown a marked ability to mutate, jumping over the human-animal barrier, thus becoming from enzootic to zoonotic. In the last years, numerous therapeutic protocols have been developed, mainly for severe acute respiratory syndromes in humans. The aim of this review is to summarize drugs or other approaches used in coronavirus infections focusing on different roles of these molecules or bacterial products on viral adhesion and replication or in modulating the host's immune system. Within the "One Health" concept, the study of viral pathogenic role and possible therapeutic approaches in both humans and animals is essential to protect public health.
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Affiliation(s)
- Giacomo Rossi
- Corresponding author at: School of Biosciences and Veterinary Medicine, University of Camerino, Via Circonvallazione 93/95 – 62024, Matelica (MC), Italy
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10
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Li Y, Liu D, Wang Y, Su W, Liu G, Dong W. The Importance of Glycans of Viral and Host Proteins in Enveloped Virus Infection. Front Immunol 2021; 12:638573. [PMID: 33995356 PMCID: PMC8116741 DOI: 10.3389/fimmu.2021.638573] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/15/2021] [Indexed: 12/15/2022] Open
Abstract
Animal viruses are parasites of animal cells that have characteristics such as heredity and replication. Viruses can be divided into non-enveloped and enveloped viruses if a lipid bilayer membrane surrounds them or not. All the membrane proteins of enveloped viruses that function in attachment to target cells or membrane fusion are modified by glycosylation. Glycosylation is one of the most common post-translational modifications of proteins and plays an important role in many biological behaviors, such as protein folding and stabilization, virus attachment to target cell receptors and inhibition of antibody neutralization. Glycans of the host receptors can also regulate the attachment of the viruses and then influence the virus entry. With the development of glycosylation research technology, the research and development of novel virus vaccines and antiviral drugs based on glycan have received increasing attention. Here, we review the effects of host glycans and viral proteins on biological behaviors of viruses, and the opportunities for prevention and treatment of viral infectious diseases.
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Affiliation(s)
- Yuqing Li
- Department of Biochemistry and Molecular Biology, Institute of Glycobiology, Dalian Medical University, Dalian, China
| | - Dongqi Liu
- The Queen's University of Belfast Joint College, China Medical University, Shenyang, China
| | - Yating Wang
- Department of Biochemistry and Molecular Biology, Institute of Glycobiology, Dalian Medical University, Dalian, China
| | - Wenquan Su
- Dalian Medical University, Dalian, China
| | - Gang Liu
- Department of Biochemistry and Molecular Biology, Institute of Glycobiology, Dalian Medical University, Dalian, China
| | - Weijie Dong
- Department of Biochemistry and Molecular Biology, Institute of Glycobiology, Dalian Medical University, Dalian, China
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11
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Zhang XL, Qu H. The Role of Glycosylation in Infectious Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1325:219-237. [PMID: 34495538 DOI: 10.1007/978-3-030-70115-4_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Glycosylation plays an important role in infectious diseases. Many important interactions between pathogens and hosts involve their carbohydrate structures (glycans). Glycan interactions can mediate adhesion, recognition, invasion, and immune evasion of pathogens. To date, changes in many protein N/O-linked glycosylation have been identified as biomarkers for the development of infectious diseases and cancers. In this review, we will discuss the principal findings and the roles of glycosylation of both pathogens and host cells in the context of human important infectious diseases. Understanding the role and mechanism of glycan-lectin interaction between pathogens and hosts may create a new paradigm for discovering novel glycan-based therapies that can lead to eradication or functional cure of pathogens infection.
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Affiliation(s)
- Xiao-Lian Zhang
- State Key Laboratory of Virology, Hubei Province Key Laboratory of Allergy and Immunology, Department of Immunology, Wuhan University School of Basic Medical Sciences, Wuhan, China.
| | - Haoran Qu
- State Key Laboratory of Virology, Hubei Province Key Laboratory of Allergy and Immunology, Department of Immunology, Wuhan University School of Basic Medical Sciences, Wuhan, China
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12
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Evans DeWald L, Starr C, Butters T, Treston A, Warfield KL. Iminosugars: A host-targeted approach to combat Flaviviridae infections. Antiviral Res 2020; 184:104881. [PMID: 32768411 PMCID: PMC7405907 DOI: 10.1016/j.antiviral.2020.104881] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/07/2020] [Accepted: 07/13/2020] [Indexed: 12/12/2022]
Abstract
N-linked glycosylation is the most common form of protein glycosylation and is required for the proper folding, trafficking, and/or receptor binding of some host and viral proteins. As viruses lack their own glycosylation machinery, they are dependent on the host's machinery for these processes. Certain iminosugars are known to interfere with the N-linked glycosylation pathway by targeting and inhibiting α-glucosidases I and II in the endoplasmic reticulum (ER). Perturbing ER α-glucosidase function can prevent these enzymes from removing terminal glucose residues on N-linked glycans, interrupting the interaction between viral glycoproteins and host chaperone proteins that is necessary for proper folding of the viral protein. Iminosugars have demonstrated broad-spectrum antiviral activity in vitro and in vivo against multiple viruses. This review discusses the broad activity of iminosugars against Flaviviridae. Iminosugars have shown favorable activity against multiple members of the Flaviviridae family in vitro and in murine models of disease, although the activity and mechanism of inhibition can be virus-specfic. While iminosugars are not currently approved for the treatment of viral infections, their potential use as future host-targeted antiviral (HTAV) therapies continues to be investigated.
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Affiliation(s)
| | - Chloe Starr
- Emergent BioSolutions, Gaithersburg, MD, 20879, USA
| | | | | | - Kelly L. Warfield
- Emergent BioSolutions, Gaithersburg, MD, 20879, USA,Corresponding author. 400 Professional Drive, Gaithersburg, MD, 20879, USA
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13
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Ströh LJ, Krey T. HCV Glycoprotein Structure and Implications for B-Cell Vaccine Development. Int J Mol Sci 2020; 21:ijms21186781. [PMID: 32947858 PMCID: PMC7555785 DOI: 10.3390/ijms21186781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/12/2020] [Accepted: 09/14/2020] [Indexed: 02/06/2023] Open
Abstract
Despite the approval of highly efficient direct-acting antivirals in the last decade Hepatitis C virus (HCV) remains a global health burden and the development of a vaccine would constitute an important step towards the control of HCV. The high genetic variability of the viral glycoproteins E1 and E2, which carry the main neutralizing determinants, together with their intrinsic structural flexibility, the high level of glycosylation that shields conserved neutralization epitopes and immune evasion using decoy epitopes renders the design of an efficient vaccine challenging. Recent structural and functional analyses have highlighted the role of the CD81 receptor binding site on E2, which overlaps with those neutralization epitopes within E2 that have been structurally characterized to date. This CD81 binding site consists of three distinct segments including “epitope I”, “epitope II” and the “CD81 binding loop”. In this review we summarize the structural features of the HCV glycoproteins that have been derived from X-ray structures of neutralizing and non-neutralizing antibody fragments complexed with either recombinant E2 or epitope-derived linear peptides. We focus on the current understanding how neutralizing antibodies interact with their cognate antigen, the structural features of the respective neutralization epitopes targeted by nAbs and discuss the implications for informed vaccine design.
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Affiliation(s)
- Luisa J. Ströh
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany;
| | - Thomas Krey
- Institute of Virology, Hannover Medical School, 30625 Hannover, Germany;
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, 23562 Luebeck, Germany
- German Center for Infection Research (DZIF), Partner Site Hannover-Braunschweig, 30625 Hannover, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Luebeck-Borstel-Riems, 23562 Luebeck, Germany
- Excellence Cluster 2155 RESIST, Hannover Medical School, 30625 Hannover, Germany
- Centre for Structural Systems Biology (CSSB), 22607 Hamburg, Germany
- Correspondence: ; Tel.: +49-(0)451–3101-3101
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14
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He L, Tzarum N, Lin X, Shapero B, Sou C, Mann CJ, Stano A, Zhang L, Nagy K, Giang E, Law M, Wilson IA, Zhu J. Proof of concept for rational design of hepatitis C virus E2 core nanoparticle vaccines. SCIENCE ADVANCES 2020; 6:eaaz6225. [PMID: 32494617 PMCID: PMC7159917 DOI: 10.1126/sciadv.aaz6225] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/22/2020] [Indexed: 05/05/2023]
Abstract
Hepatitis C virus (HCV) envelope glycoproteins E1 and E2 are responsible for cell entry, with E2 being the major target of neutralizing antibodies (NAbs). Here, we present a comprehensive strategy for B cell-based HCV vaccine development through E2 optimization and nanoparticle display. We redesigned variable region 2 in a truncated form (tVR2) on E2 cores derived from genotypes 1a and 6a, resulting in improved stability and antigenicity. Crystal structures of three optimized E2 cores with human cross-genotype NAbs (AR3s) revealed how the modified tVR2 stabilizes E2 without altering key neutralizing epitopes. We then displayed these E2 cores on 24- and 60-meric nanoparticles and achieved substantial yield and purity, as well as enhanced antigenicity. In mice, these nanoparticles elicited more effective NAb responses than soluble E2 cores. Next-generation sequencing (NGS) defined distinct B cell patterns associated with nanoparticle-induced antibody responses, which target the conserved neutralizing epitopes on E2 and cross-neutralize HCV genotypes.
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Affiliation(s)
- Linling He
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Netanel Tzarum
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Xiaohe Lin
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Benjamin Shapero
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Cindy Sou
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Colin J Mann
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Armando Stano
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Lei Zhang
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Kenna Nagy
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Erick Giang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ian A Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jiang Zhu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
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15
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An Engineered Microvirin Variant with Identical Structural Domains Potently Inhibits Human Immunodeficiency Virus and Hepatitis C Virus Cellular Entry. Viruses 2020; 12:v12020199. [PMID: 32054060 PMCID: PMC7077325 DOI: 10.3390/v12020199] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 01/22/2020] [Indexed: 02/08/2023] Open
Abstract
Microvirin (MVN) is one of the human immunodeficiency virus (HIV-1) entry inhibitor lectins, which consists of two structural domains sharing 35% sequence identity and contrary to many other antiviral lectins, it exists as a monomer. In this study, we engineered an MVN variant, LUMS1, consisting of two domains with 100% sequence identity, thereby reducing the chemical heterogeneity, which is a major factor in eliciting immunogenicity. We determined carbohydrate binding of LUMS1 through NMR chemical shift perturbation and tested its anti-HIV activity in single-round infectivity assay and its anti-hepatitis C virus (HCV) activity in three different assays including HCVcc, HCVpp, and replicon assays. We further investigated the effect of LUMS1 on the activation of T helper (Th) and B cells through flow cytometry. LUMS1 showed binding to α(1-2)mannobiose, the minimum glycan epitope of MVN, potently inhibited HIV-1 and HCV with EC50 of 37.2 and 45.3 nM, respectively, and showed negligible cytotoxicity with CC50 > 10 µM against PBMCs, Huh-7.5 and HepG2 cells, and 4.9 µM against TZM-bl cells. LUMS1 did not activate Th cells, and its stimulatory effect on B cells was markedly less as compared to MVN. Together, with these effects, LUMS1 represents a potential candidate for the development of antiviral therapies.
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16
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Cao L, Yu B, Kong D, Cong Q, Yu T, Chen Z, Hu Z, Chang H, Zhong J, Baker D, He Y. Functional expression and characterization of the envelope glycoprotein E1E2 heterodimer of hepatitis C virus. PLoS Pathog 2019; 15:e1007759. [PMID: 31116791 PMCID: PMC6530877 DOI: 10.1371/journal.ppat.1007759] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 04/12/2019] [Indexed: 12/11/2022] Open
Abstract
Hepatitis C virus (HCV) is a member of Hepacivirus and belongs to the family of Flaviviridae. HCV infects millions of people worldwide and may lead to cirrhosis and hepatocellular carcinoma. HCV envelope proteins, E1 and E2, play critical roles in viral cell entry and act as major epitopes for neutralizing antibodies. However, unlike other known flaviviruses, it has been challenging to study HCV envelope proteins E1E2 in the past decades as the in vitro expressed E1E2 heterodimers are usually of poor quality, making the structural and functional characterization difficult. Here we express the ectodomains of HCV E1E2 heterodimer with either an Fc-tag or a de novo designed heterodimeric tag and are able to isolate soluble E1E2 heterodimer suitable for functional and structural studies. Then we characterize the E1E2 heterodimer by electron microscopy and model the structure by the coevolution based modeling strategy with Rosetta, revealing the potential interactions between E1 and E2. Moreover, the E1E2 heterodimer is applied to examine the interactions with the known HCV receptors, neutralizing antibodies as well as the inhibition of HCV infection, confirming the functionality of the E1E2 heterodimer and the binding profiles of E1E2 with the cellular receptors. Therefore, the expressed E1E2 heterodimer would be a valuable target for both viral studies and vaccination against HCV. Hepatitis C virus (HCV) is an enveloped virus that infects millions of people worldwide and may lead to cirrhosis and hepatocellular carcinoma. HCV has two envelope proteins, E1 and E2, which form heterodimers on viral surface and are critical for HCV cell entry. However, current studies of HCV E1E2 are often limited by the poor quality of the in vitro expressed E1E2 heterodimers. Here we express the ectodomains of HCV E1E2 with different tags, and are able to isolate soluble E1E2 ectodomains suitable for structural and functional studies. Then we generate the 3D reconstruction of E1E2 heterodimer by electron microscopy and also model the E1E2 structure by the coevolution based strategy with Rosetta, showing the potential interactions between E1 and E2. Moreover, the E1E2 heterodimer is applied to examine the interactions with the HCV cellular receptors, neutralizing antibodies as well as the inhibition of HCV infection. These results suggest that the expressed E1E2 heterodimer would be a promising target for both viral studies and vaccination against HCV.
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Affiliation(s)
- Longxing Cao
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Bowen Yu
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
| | - Dandan Kong
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
| | - Qian Cong
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Tao Yu
- CAS Key Laboratory of Molecular Virology and Immunology, Unit of Viral Hepatitis, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Zibo Chen
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
| | - Zhenzheng Hu
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
| | - Haishuang Chang
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
| | - Jin Zhong
- CAS Key Laboratory of Molecular Virology and Immunology, Unit of Viral Hepatitis, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- Institute for Protein Design, University of Washington, Seattle, Washington, United States of America
- Howard Hughes Medical Institute, University of Washington, Seattle, Washington, United States of America
| | - Yongning He
- State Key Laboratory of Molecular Biology, National Center for Protein Science Shanghai, Shanghai Science Research Center, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai, China
- * E-mail:
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17
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Moustafa RI, Dubuisson J, Lavie M. Function of the HCV E1 envelope glycoprotein in viral entry and assembly. Future Virol 2019. [DOI: 10.2217/fvl-2018-0180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
HCV envelope glycoproteins, E1 and E2, are multifunctional proteins. Until recently, E2 glycoprotein was thought to be the fusion protein and was the focus of investigations. However, the recently obtained partial structures of E2 and E1 rather support a role for E1 alone or in association with E2 in HCV fusion. Moreover, they suggest that HCV harbors a new fusion mechanism, distinct from that of other members of the Flaviviridae family. In this context, E1 aroused a renewed interest. Recent functional characterizations of E1 revealed a more important role than previously thought in entry and assembly. Thus, E1 is involved in the viral genome encapsidation step and influences the association of the virus with lipoprotein components. Moreover, E1 modulates HCV–receptor interaction and participates in a late entry step potentially fusion. In this review, we outline our current knowledge on E1 functions in HCV assembly and entry.
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Affiliation(s)
- Rehab I Moustafa
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 – UMR 8204 – CIIL– Centre d'Infection et d'Immunité de Lille, F-59000 Lille, France
- Department of Microbial Biotechnology, Genetic Engineering & Biotechnology Division, National Research Center, Dokki, Cairo, Egypt
| | - Jean Dubuisson
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 – UMR 8204 – CIIL– Centre d'Infection et d'Immunité de Lille, F-59000 Lille, France
| | - Muriel Lavie
- Université de Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 – UMR 8204 – CIIL– Centre d'Infection et d'Immunité de Lille, F-59000 Lille, France
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18
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Tzarum N, Giang E, Kong L, He L, Prentoe J, Augestad E, Hua Y, Castillo S, Lauer GM, Bukh J, Zhu J, Wilson IA, Law M. Genetic and structural insights into broad neutralization of hepatitis C virus by human V H1-69 antibodies. SCIENCE ADVANCES 2019; 5:eaav1882. [PMID: 30613781 PMCID: PMC6314831 DOI: 10.1126/sciadv.aav1882] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 11/27/2018] [Indexed: 05/19/2023]
Abstract
An effective vaccine to the antigenically diverse hepatitis C virus (HCV) must target conserved immune epitopes. Here, we investigate cross-neutralization of HCV genotypes by broadly neutralizing antibodies (bNAbs) encoded by the relatively abundant human gene family V H 1-69. We have deciphered the molecular requirements for cross-neutralization by this unique class of human antibodies from crystal structures of HCV E2 in complex with bNAbs. An unusually high binding affinity is found for germ line-reverted versions of VH1-69 precursor antibodies, and neutralization breadth is acquired during affinity maturation. Deep sequencing analysis of an HCV-immune B cell repertoire further demonstrates the importance of the V H 1-69 gene family in the generation of HCV bNAbs. This study therefore provides critical insights into immune recognition of HCV with important implications for rational vaccine design.
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Affiliation(s)
- Netanel Tzarum
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Erick Giang
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Leopold Kong
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Linling He
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elias Augestad
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Yuanzi Hua
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Shaun Castillo
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Georg M. Lauer
- Gastrointestinal Unit and Liver Center, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jiang Zhu
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Ian A. Wilson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
- Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA
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19
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Ashraf MU, Iman K, Khalid MF, Salman HM, Shafi T, Rafi M, Javaid N, Hussain R, Ahmad F, Shahzad-Ul-Hussan S, Mirza S, Shafiq M, Afzal S, Hamera S, Anwar S, Qazi R, Idrees M, Qureshi SA, Chaudhary SU. Evolution of efficacious pangenotypic hepatitis C virus therapies. Med Res Rev 2018; 39:1091-1136. [PMID: 30506705 DOI: 10.1002/med.21554] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 10/11/2018] [Accepted: 10/11/2018] [Indexed: 12/12/2022]
Abstract
Hepatitis C compromises the quality of life of more than 350 million individuals worldwide. Over the last decade, therapeutic regimens for treating hepatitis C virus (HCV) infections have undergone rapid advancements. Initially, structure-based drug design was used to develop molecules that inhibit viral enzymes. Subsequently, establishment of cell-based replicon systems enabled investigations into various stages of HCV life cycle including its entry, replication, translation, and assembly, as well as role of host proteins. Collectively, these approaches have facilitated identification of important molecules that are deemed essential for HCV life cycle. The expanded set of putative virus and host-encoded targets has brought us one step closer to developing robust strategies for efficacious, pangenotypic, and well-tolerated medicines against HCV. Herein, we provide an overview of the development of various classes of virus and host-directed therapies that are currently in use along with others that are undergoing clinical evaluation.
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Affiliation(s)
- Muhammad Usman Ashraf
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan.,Virology Laboratory, Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Kanzal Iman
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Muhammad Farhan Khalid
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan.,Department of Biomedical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | - Hafiz Muhammad Salman
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan.,Plant Biotechnology Laboratory, Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan
| | - Talha Shafi
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Momal Rafi
- Department of Statistics, University of Gujrat, Gujrat, Pakistan
| | - Nida Javaid
- Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Rashid Hussain
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Fayyaz Ahmad
- Department of Statistics, University of Gujrat, Gujrat, Pakistan
| | | | - Shaper Mirza
- Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
| | - Muhammad Shafiq
- Plant Biotechnology Laboratory, Institute of Agricultural Sciences, University of the Punjab, Lahore, Pakistan
| | - Samia Afzal
- Virology Laboratory, Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan
| | - Sadia Hamera
- Department of Plant Genetics, Institute of Life Sciences, University of Rostock, Germany
| | - Saima Anwar
- Department of Biomedical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | - Romena Qazi
- Department of Pathology, Shaukat Khanum Memorial Cancer Hospital & Research Centre, Lahore, Pakistan
| | - Muhammad Idrees
- Virology Laboratory, Center of Excellence in Molecular Biology, University of the Punjab, Lahore, Pakistan.,Hazara University, Mansehra, Pakistan
| | - Sohail A Qureshi
- Institute of Integrative Biosciences, CECOS-University of Information Technology and Emerging Sciences, Peshawar, Pakistan
| | - Safee Ullah Chaudhary
- Biomedical Informatics Research Laboratory, Department of Biology, Lahore University of Management Sciences, Lahore, Pakistan
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20
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Virus discovery reveals frequent infection by diverse novel members of the Flaviviridae in wild lemurs. Arch Virol 2018; 164:509-522. [PMID: 30460488 DOI: 10.1007/s00705-018-4099-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2018] [Accepted: 10/31/2018] [Indexed: 12/13/2022]
Abstract
Lemurs are highly endangered mammals inhabiting the forests of Madagascar. In this study, we performed virus discovery on serum samples collected from 84 wild lemurs and identified viral sequence fragments from 4 novel viruses within the family Flaviviridae, including members of the genera Hepacivirus and Pegivirus. The sifaka hepacivirus (SifHV, two genotypes) and pegivirus (SifPgV, two genotypes) were discovered in the diademed sifaka (Propithecus diadema), while other pegiviral fragments were detected in samples from the indri (Indri indri, IndPgV) and the weasel sportive lemur (Lepilemur mustelinus, LepPgV). Although data are preliminary, each viral species appeared host species-specific and frequent infection was detected (18 of 84 individuals were positive for at least one virus). The complete coding sequence and partial 5' and 3' untranslated regions (UTRs) were obtained for SifHV and its genomic organization was consistent with that of other hepaciviruses, with one unique polyprotein and highly structured UTRs. Phylogenetic analyses showed the SifHV belonged to a clade that includes several viral species identified in rodents from Asia and North America, while SifPgV and IndPgV were more closely related to pegiviral species A and C, that include viruses found in humans as well as New- and Old-World monkeys. Our results support the current proposed model of virus-host co-divergence with frequent occurrence of cross-species transmission for these genera and highlight how the discovery of more members of the Flaviviridae can help clarify the ecology and evolutionary history of these viruses. Furthermore, this knowledge is important for conservation and captive management of lemurs.
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21
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Tarr AW, Backx M, Hamed MR, Urbanowicz RA, McClure CP, Brown RJP, Ball JK. Immunization with a synthetic consensus hepatitis C virus E2 glycoprotein ectodomain elicits virus-neutralizing antibodies. Antiviral Res 2018; 160:25-37. [PMID: 30217650 DOI: 10.1016/j.antiviral.2018.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 09/06/2018] [Accepted: 09/10/2018] [Indexed: 01/06/2023]
Abstract
Global eradication of hepatitis C virus (HCV) infection will require an efficacious vaccine capable of eliciting protective immunity against genetically diverse HCV strains. Natural spontaneous resolution of HCV infection is associated with production of broadly-neutralizing antibodies targeting the HCV glycoproteins E1 and E2. As such, production of cross-neutralizing antibodies is an important endpoint for experimental vaccine trials. Varying success generating cross-neutralizing antibodies has been achieved with immunogens derived from naturally-occurring HCV strains. In this study the challenge of minimising the genetic diversity between the vaccine strain and circulating HCV isolates was addressed. Two novel synthetic E2 glycoprotein immunogens (NotC1 and NotC2) were derived from consensus nucleotide sequences deduced from samples of circulating genotype 1 HCV strains. These two synthetic sequences differed in their relative positions in the overall genotype 1a/1b phylogeny. Expression of these constructs in Drosophila melanogaster S2 cells resulted in high yields of correctly-folded, monomeric E2 protein, which were recognised by broadly neutralizing monoclonal antibodies. Immunization of guinea pigs with either of these consensus immunogens, or a comparable protein representing a circulating genotype 1a strain resulted in high titres of cross-reactive anti-E2 antibodies. All immunogens generated antibodies capable of neutralizing the H77 strain, but NotC1 elicited antibodies that more potently neutralized virus entry. These vaccine-induced antibodies neutralized some viruses representing genotype 1, but not strains representing genotype 2 or genotype 3. Thus, while this approach to vaccine design resulted in correctly folded, immunogenic protein, cross-neutralizing epitopes were not preferentially targeted by the host immune response generated by this immunogen. Greater immunofocussing of vaccines to common epitopes is necessary to successfully elicit broadly neutralizing antibodies.
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Affiliation(s)
- Alexander W Tarr
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - Matthijs Backx
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - Mohamed R Hamed
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK; Medical Microbiology and Immunology Department, Faculty of Medicine, Mansoura University, Egypt
| | - Richard A Urbanowicz
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - C Patrick McClure
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - Richard J P Brown
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK
| | - Jonathan K Ball
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust, UK; School of Life Sciences, Faculty of Medicine and Health Sciences, University of Nottingham, Nottingham, UK.
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22
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Krol E, Wandzik I, Pastuch-Gawolek G, Szewczyk B. Anti-Hepatitis C Virus Activity of Uridine Derivatives of 2-Deoxy Sugars. Molecules 2018; 23:molecules23071547. [PMID: 29954068 PMCID: PMC6099588 DOI: 10.3390/molecules23071547] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 06/22/2018] [Accepted: 06/26/2018] [Indexed: 12/16/2022] Open
Abstract
Hepatitis C virus (HCV), the etiological agent of the most common and dangerous diseases of the liver, is a major health problem worldwide. Despite many attempts, there is still no vaccine available. Although many drugs have been approved for use mostly in combination regimen, their high costs make them out of reach in less developed regions. Previously, we have synthesized a series of compounds belonging to uridine derivatives of 2-deoxy sugars and have proved that some of them possess antiviral activity against influenza A virus associated with N-glycosylation inhibition. Here, we analyze the antiviral properties of these compounds against HCV. Using cell culture-derived HCV (HCVcc), HCV pseudoparticles (HCVpp), and replicon cell lines, we have shown high anti-HCV activity of two compounds. Our results indicated that compounds 2 and 4 significantly reduced HCVcc propagation with IC50 values in low μM range. Further experiments using the HCVpp system confirmed that both compounds significantly impaired the infectivity of produced HCVpp due to the inhibition of the correct maturation of viral glycoproteins. Overall, our results suggest that inhibiting the glycosylation process might be a good target for new therapeutics not only against HCV, but other important viral pathogens which contain envelopes with highly glycosylated proteins.
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Affiliation(s)
- Ewelina Krol
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland.
| | - Ilona Wandzik
- Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Krzywoustego 4, 44-100 Gliwice, Poland.
- Biotechnology Center, Silesian University of Technology, Krzywoustego 8, 44-100 Gliwice, Poland.
| | - Gabriela Pastuch-Gawolek
- Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Faculty of Chemistry, Silesian University of Technology, Krzywoustego 4, 44-100 Gliwice, Poland.
- Biotechnology Center, Silesian University of Technology, Krzywoustego 8, 44-100 Gliwice, Poland.
| | - Boguslaw Szewczyk
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland.
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23
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Tong Y, Lavillette D, Li Q, Zhong J. Role of Hepatitis C Virus Envelope Glycoprotein E1 in Virus Entry and Assembly. Front Immunol 2018; 9:1411. [PMID: 29971069 PMCID: PMC6018474 DOI: 10.3389/fimmu.2018.01411] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/06/2018] [Indexed: 12/22/2022] Open
Abstract
Hepatitis C virus (HCV) glycoproteins E1 and E2 form a heterodimer to constitute viral envelope proteins, which play an essential role in virus entry. E1 does not directly interact with host receptors, and its functions in viral entry are exerted mostly through its interaction with E2 that directly binds the receptors. HCV enters the host cell via receptor-mediated endocytosis during which the fusion of viral and host endosomal membranes occurs to release viral genome to cytoplasm. A putative fusion peptide in E1 has been proposed to participate in membrane fusion, but its exact role and underlying molecular mechanisms remain to be deciphered. Recently solved crystal structures of the E2 ectodomains and N-terminal of E1 fail to reveal a classical fusion-like structure in HCV envelope glycoproteins. In addition, accumulating evidence suggests that E1 also plays an important role in virus assembly. In this mini-review, we summarize current knowledge on HCV E1 including its structure and biological functions in virus entry, fusion, and assembly, which may provide clues for developing HCV vaccines and more effective antivirals.
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Affiliation(s)
- Yimin Tong
- Unit of Viral Hepatitis, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Dimitri Lavillette
- Unit of Interspecies Transmission of Arboviruses and Antivirals, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Qingchao Li
- Unit of Viral Hepatitis, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jin Zhong
- Unit of Viral Hepatitis, CAS Key Laboratory of Molecular Virology and Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
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24
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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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25
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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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26
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Lavie M, Hanoulle X, Dubuisson J. Glycan Shielding and Modulation of Hepatitis C Virus Neutralizing Antibodies. Front Immunol 2018; 9:910. [PMID: 29755477 PMCID: PMC5934428 DOI: 10.3389/fimmu.2018.00910] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/12/2018] [Indexed: 12/11/2022] Open
Abstract
Hepatitis C virus (HCV) envelope glycoprotein heterodimer, E1E2, plays an essential role in virus entry and assembly. Furthermore, due to their exposure at the surface of the virion, these proteins are the major targets of anti-HCV neutralizing antibodies. Their ectodomain are heavily glycosylated with up to 5 sites on E1 and up to 11 sites on E2 modified by N-linked glycans. Thus, one-third of the molecular mass of E1E2 heterodimer corresponds to glycans. Despite the high sequence variability of E1 and E2, N-glycosylation sites of these proteins are generally conserved among the seven major HCV genotypes. N-glycans have been shown to be involved in E1E2 folding and modulate different functions of the envelope glycoproteins. Indeed, site-directed mutagenesis studies have shown that specific glycans are needed for virion assembly and infectivity. They can notably affect envelope protein entry functions by modulating their affinity for HCV receptors and their fusion activity. Importantly, glycans have also been shown to play a key role in immune evasion by masking antigenic sites targeted by neutralizing antibodies. It is well known that the high mutational rate of HCV polymerase facilitates the appearance of neutralization resistant mutants, and occurrence of mutations leading to glycan shifting is one of the mechanisms used by this virus to escape host humoral immune response. As a consequence of the importance of the glycan shield for HCV immune evasion, the deletion of N-glycans also leads to an increase in E1E2 immunogenicity and can induce a more potent antibody response against HCV.
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Affiliation(s)
- Muriel Lavie
- University of Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection & Immunity of Lille, Lille, France
| | - Xavier Hanoulle
- University of Lille, CNRS, UMR 8576, UGSF, Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Jean Dubuisson
- University of Lille, CNRS, INSERM, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center for Infection & Immunity of Lille, Lille, France
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27
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Development and characterization of a human monoclonal antibody targeting the N-terminal region of hepatitis C virus envelope glycoprotein E1. Virology 2017; 514:30-41. [PMID: 29128754 DOI: 10.1016/j.virol.2017.10.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 10/16/2017] [Accepted: 10/20/2017] [Indexed: 12/23/2022]
Abstract
Monoclonal antibodies (mAbs) targeting the hepatitis C virus (HCV) envelope have been raised mainly against envelope protein 2 (E2), while the antigenic epitopes of envelope protein 1 (E1) are not fully identified. Here we describe the detailed characterization of a human mAb, designated A6, generated from an HCV genotype 1b infected patient. ELISA results showed reactivity of mAb A6 to full-length HCV E1E2 of genotypes 1a, 1b and 2a. Epitope mapping identified a region spanning amino acids 230-239 within the N-terminal region of E1 as critical for binding. Antibody binding to this epitope was not conformation dependent. Neutralization assays showed that mAb A6 lacks neutralizing capacity and does not interfere with the activity of known neutralizing antibodies. In summary, mAb A6 is an important tool to study the structure and function of E1 within the viral envelope, a crucial step in the development of an effective prophylactic HCV vaccine.
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28
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Singh RS, Walia AK, Khattar JS, Singh DP, Kennedy JF. Cyanobacterial lectins characteristics and their role as antiviral agents. Int J Biol Macromol 2017; 102:475-496. [PMID: 28437766 DOI: 10.1016/j.ijbiomac.2017.04.041] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/29/2017] [Accepted: 04/11/2017] [Indexed: 12/12/2022]
Abstract
Lectins are ubiquitous proteins/glycoproteins of non-immune origin that bind reversibly to carbohydrates in non-covalent and highly specific manner. These lectin-glycan interactions could be exploited for establishment of novel therapeutics, targeting the adherence stage of viruses and thus helpful in eliminating wide spread viral infections. Here the review focuses on the haemagglutination activity, carbohydrate specificity and characteristics of cyanobacterial lectins. Cyanobacterial lectins exhibiting high specificity towards mannose or complex glycans have potential role as anti-viral agents. Prospective role of cyanobacterial lectins in targeting various diseases of worldwide concern such as HIV, hepatitis, herpes, influenza and ebola viruses has been discussed extensively. The review also lays emphasis on recent studies involving structural analysis of glycan-lectin interactions which in turn influence their mechanism of action. Altogether, the promising approach of these cyanobacterial lectins provides insight into their use as antiviral agents.
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Affiliation(s)
- Ram Sarup Singh
- Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University, Patiala 147002, Punjab, India.
| | - Amandeep Kaur Walia
- Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University, Patiala 147002, Punjab, India
| | | | - Davinder Pal Singh
- Department of Botany, Punjabi University, Patiala 147 002, Punjab, India
| | - John F Kennedy
- Chembiotech Laboratories, Advanced Science & Technology Institute, Kyrewood House, Tenbury Wells, Worcestershire WR1 8SG, UK
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29
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Codon Optimization Leads to Functional Impairment of RD114-TR Envelope Glycoprotein. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2017; 4:102-114. [PMID: 28344996 PMCID: PMC5363313 DOI: 10.1016/j.omtm.2017.01.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 01/04/2017] [Indexed: 01/13/2023]
Abstract
Lentiviral vectors (LVs) are a highly valuable tool for gene transfer currently exploited in basic, applied, and clinical studies. Their optimization is therefore very important for the field of vectorology and gene therapy. A key molecule for LV function is the envelope because it guides cell entry. The most commonly used in transiently produced LVs is the vesicular stomatitis virus glycoprotein (VSV-G) envelope, whose continuous expression is, however, toxic for stable LV producer cells. In contrast, the feline endogenous retroviral RD114-TR envelope is suitable for stable LV manufacturing, being well tolerated by producer cells under constitutive expression. We have previously reported successful, transient and stable production of LVs pseudotyped with RD114-TR for good transduction of T lymphocytes and CD34+ cells. To further improve RD114-TR-pseudotyped LV cell entry by increasing envelope expression, we codon-optimized the RD114-TR open reading frame (ORF). Here we show that, despite the RD114-TRco precursor being produced at a higher level than the wild-type counterpart, it is unexpectedly not duly glycosylated, exported to the cytosol, and processed. Correct cleavage of the precursor in the functional surface and transmembrane subunits is prevented in vivo, and, consequently, the unprocessed precursor is incorporated into LVs, making them inactive.
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30
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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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31
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Dzwonek AB, Woźniakowska-GĘsicka T, Wiśniewska-Ligier M. Mannose-binding lectin in chronic hepatitis C in children. Scand J Gastroenterol 2016; 50:1276-84. [PMID: 25956563 DOI: 10.3109/00365521.2015.1006673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE To investigate effect of mannose-binding lectin (MBL) genetic polymorphisms and phenotype in chronic hepatitis C and its impact on response to antiviral therapy in children. METHODS Fifty four children with chronic hepatitis C, aged 2.5-18 years were enrolled. Forty-five children were treated with interferon-α (IFN-α) alone (n = 2) or IFN-α and ribavirin (n = 43). Twenty-one children who responded to antiviral therapy were defined as sustained responders to therapy (IFN-SR). Before therapy, MBL genotypes and serum MBL levels (by ELISA) were determined. MBL genotype distribution and levels were correlated to disease characteristics and response to therapy. RESULTS Children with chronic hepatitis C who did not respond to antiviral therapy (IFN-NR) presented more frequently MBL2 polymorphisms, although this did not reach significance (p = 0.08). MBL levels were significantly lower in children classified as IFN-NR when compared to children defined as IFN-SR (1.623 ng/ml vs. 3.699 ng/ml), (p = 0.04). Serum activity levels of ALT and AST were higher in children with A/O MBL genotype when compared to group with A/A genotype (p < 0.05). CONCLUSIONS Our findings suggest negative effect of MBL deficiency (defined by genotype and phenotype) on progression of chronic hepatitis C in children and response to antiviral therapy.
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32
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Li Y, Wang R, Du X, Zhang M, Xie M. Genome-wide analysis for identification of adaptive diversification between hepatitis C virus subtypes 1a and 1b. Can J Microbiol 2016; 62:608-16. [PMID: 27277863 DOI: 10.1139/cjm-2016-0156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hepatitis C virus (HCV) is a major cause of liver disease and has been estimated to infect approximately 2%-3% of the world's population. HCV genotype 1 is the subject of intense research and clinical investigations because of its worldwide prevalence and poor access to treatment for patients in developing countries and marginalized populations. The predominant subtypes 1a and 1b of HCV genotype 1 present considerable differences in epidemiological features. However, the genetic signature underlying such phenotypic functional divergence is still an open question. Here, we performed a genome-wide evolutionary study on HCV subtypes 1a and 1b. The results show that adaptive selection has driven the diversification between these subtypes. Furthermore, the major adaptive divergence-related changes have occurred on proteins E1, NS4B, NS5A, and NS5B. Structurally, a number of adaptively selected sites cluster in functional regions potentially relevant to (i) membrane attachment and (ii) the interactions with viral and host cell factors and the genome template. These results might provide helpful hints about the molecular determinants of epidemiological divergence between HCV 1a and 1b.
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Affiliation(s)
- Yan Li
- a College of Animal Science and Technology, Sichuan Agricultural University, Wenjiang, People's Republic of China
| | - Ruirui Wang
- b School of Pharmacy, Yunnan University of Traditional Chinese Medicine, Kunming, Yunnan, People's Republic of China
| | - Xiaogang Du
- c College of Life Science, Sichuan Agricultural University, Yaan, People's Republic of China
| | - Mingwang Zhang
- a College of Animal Science and Technology, Sichuan Agricultural University, Wenjiang, People's Republic of China
| | - Meng Xie
- c College of Life Science, Sichuan Agricultural University, Yaan, People's Republic of China
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33
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Generation and Characterization of Monoclonal Antibodies against a Cyclic Variant of Hepatitis C Virus E2 Epitope 412-422. J Virol 2016; 90:3745-59. [PMID: 26819303 PMCID: PMC4794675 DOI: 10.1128/jvi.02397-15] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 01/17/2016] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED The hepatitis C virus (HCV) E2 envelope glycoprotein is crucial for virus entry into hepatocytes. A conserved region of E2 encompassing amino acids 412 to 423 (epitope I) and containing Trp420, a residue critical for virus entry, is recognized by several broadly neutralizing antibodies. Peptides embodying this epitope I sequence adopt a β-hairpin conformation when bound to neutralizing monoclonal antibodies (MAbs) AP33 and HCV1. We therefore generated new mouse MAbs that were able to bind to a cyclic peptide containing E2 residues 412 to 422 (C-epitope I) but not to the linear counterpart. These MAbs bound to purified E2 with affinities of about 50 nM, but they were unable to neutralize virus infection. Structural analysis of the complex between C-epitope I and one of our MAbs (C2) showed that the Trp420 side chain is largely buried in the combining site and that the Asn417 side chain, which is glycosylated in E2 and solvent exposed in other complexes, is slightly buried upon C2 binding. Also, the orientation of the cyclic peptide in the antibody-combining site is rotated by 180° compared to the orientations of the other complexes. All these structural features, however, do not explain the lack of neutralization activity. This is instead ascribed to the high degree of selectivity of the new MAbs for the cyclic epitope and to their inability to interact with the epitope in more flexible and extended conformations, which recent data suggest play a role in the mechanisms of neutralization escape. IMPORTANCE Hepatitis C virus (HCV) remains a major health care burden, affecting almost 3% of the global population. The conserved epitope comprising residues 412 to 423 of the viral E2 glycoprotein is a valid vaccine candidate because antibodies recognizing this region exhibit potent neutralizing activity. This epitope adopts a β-hairpin conformation when bound to neutralizing MAbs. We explored the potential of cyclic peptides mimicking this structure to elicit anti-HCV antibodies. MAbs that specifically recognize a cyclic variant of the epitope bind to soluble E2 with a lower affinity than other blocking antibodies and do not neutralize virus. The structure of the complex between one such MAb and the cyclic epitope, together with new structural data showing the linear peptide bound to neutralizing MAbs in extended conformations, suggests that the epitope displays a conformational flexibility that contributes to neutralization escape. Such features can be of major importance for the design of epitope-based anti-HCV vaccines.
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34
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Hopcraft SE, Evans MJ. Selection of a hepatitis C virus with altered entry factor requirements reveals a genetic interaction between the E1 glycoprotein and claudins. Hepatology 2015; 62:1059-69. [PMID: 25820616 PMCID: PMC4587996 DOI: 10.1002/hep.27815] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 03/23/2015] [Indexed: 01/08/2023]
Abstract
UNLABELLED Hepatitis C virus (HCV) cell entry is a complex, multistep process requiring numerous host cell factors, including the tight junction protein claudin-1 (CLDN1). It is not known whether CLDN1 and the HCV glycoproteins physically interact. Therefore, the focus of this work was to study genetic interactions between CLDN1 and HCV. We used CRISPR technology to generate CLDN1 knockout (KO) Huh-7.5 cells, which could not be infected by genotype 2a Jc1 HCV unless CLDN1 expression was restored. Passage of Jc1-transfected CLDN1 KO cells resulted in the selection of a virus that could infect these cells. This virus encoded a single mutation, H316N (numbered relative to the HCV polyprotein), in the E1 glycoprotein. Whereas Jc1 H316N efficiently infected cells lacking CLDN1, such infection was blocked by an antibody targeting CLDN6, another member of the claudin family that is expressed in these cells. Furthermore, HuH6 cells, which express CLDN6, but not CLDN1, were infectable only with the mutant virus. Thus, this mutant virus adapted to the loss of CLDN1 by developing the capacity to utilize other CLDNs. Indeed, CLDN1/CLDN6 double-KO Huh-7.5 cells supported infection by the mutant virus only when CLDN1, CLDN6, or CLDN9 was expressed. Finally, this phenotype was not genotype dependent, given that the H316N mutation rendered a Japanese fulminant hepatitis 1 chimeric HCV genome encoding the genotype 5a glycoproteins able to utilize CLDN6 for host cell entry. CONCLUSION These data demonstrate plasticity of HCV virus-host interactions, where a previously CLDN1-dependent virus was capable of evolving to use CLDN6. They also reveal a role for E1 in determining entry factor usage and imply a direct, physical interaction between E1 and CLDNs.
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Affiliation(s)
- Sharon E Hopcraft
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Matthew J Evans
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY
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35
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Urbaczek AC, Ximenes VF, Afonso A, Generoso WC, Nogueira CT, Tansini A, Cappelini LTD, Malagó Júnior W, da Silva FH, da Fonseca LM, da Costa PI. Recombinant hepatitis C virus-envelope protein 2 interactions with low-density lipoprotein/CD81 receptors. Mem Inst Oswaldo Cruz 2015; 110:534-42. [PMID: 26018451 PMCID: PMC4501418 DOI: 10.1590/0074-02760140441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Accepted: 03/20/2015] [Indexed: 02/08/2023] Open
Abstract
Hepatitis C virus (HCV) envelope protein 2 (E2) is involved in viral binding to host cells. The aim of this work was to produce recombinant E2B and E2Y HCV proteins in Escherichia coli and Pichia pastoris, respectively, and to study their interactions with low-density lipoprotein receptor (LDLr) and CD81 in human umbilical vein endothelial cells (HUVEC) and the ECV304 bladder carcinoma cell line. To investigate the effects of human LDL and differences in protein structure (glycosylated or not) on binding efficiency, the recombinant proteins were either associated or not associated with lipoproteins before being assayed. The immunoreactivity of the recombinant proteins was analysed using pooled serum samples that were either positive or negative for hepatitis C. The cells were immunophenotyped by LDLr and CD81 using flow cytometry. Binding and binding inhibition assays were performed in the presence of LDL, foetal bovine serum (FCS) and specific antibodies. The results revealed that binding was reduced in the absence of FCS, but that the addition of human LDL rescued and increased binding capacity. In HUVEC cells, the use of antibodies to block LDLr led to a significant reduction in the binding of E2B and E2Y. CD81 antibodies did not affect E2B and E2Y binding. In ECV304 cells, blocking LDLr and CD81 produced similar effects, but they were not as marked as those that were observed in HUVEC cells. In conclusion, recombinant HCV E2 is dependent on LDL for its ability to bind to LDLr in HUVEC and ECV304 cells. These findings are relevant because E2 acts to anchor HCV to host cells; therefore, high blood levels of LDL could enhance viral infectivity in chronic hepatitis C patients.
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Affiliation(s)
- Ana Carolina Urbaczek
- Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista, Bauru, SP, Brasil
| | - Valdecir Farias Ximenes
- Departamento de Química, Faculdade de Ciências, Universidade Estadual Paulista, Bauru, SP, Brasil
| | - Ana Afonso
- Unidade de Parasitologia Médica e Microbiologia,, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Wesley Cardoso Generoso
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brasil
| | - Camila Tita Nogueira
- Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista, Bauru, SP, Brasil
| | - Aline Tansini
- Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista, Bauru, SP, Brasil
| | - Luciana Teresa Dias Cappelini
- Departamento de Química e Física Molecular, Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP, Brasil
| | - Wilson Malagó Júnior
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, SP, Brasil
| | | | - Luiz Marcos da Fonseca
- Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista, Bauru, SP, Brasil
| | - Paulo Inácio da Costa
- Departamento de Análises Clínicas, Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista, Bauru, SP, Brasil
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Khan AG, Miller MT, Marcotrigiano J. HCV glycoprotein structures: what to expect from the unexpected. Curr Opin Virol 2015; 12:53-8. [PMID: 25790756 DOI: 10.1016/j.coviro.2015.02.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 02/19/2015] [Indexed: 01/19/2023]
Abstract
Hepatitis C virus (HCV) is continuing to spread worldwide, adding three million new infections each year. Currently approved therapies are highly effective; however, access to them is limited due to the high cost of treatment. Therefore, a cost effective vaccine and alternative antivirals remain essential. HCV envelope glycoproteins, E1 and E2, heterodimerize on the virion surface and are the major determinant for virus pathogenicity and host immune response. Recent structural insights into amino-terminal domain of E1 and core of E2 have revealed unexpected folds not present in glycoproteins from related viruses. Here we discuss these structural findings with respect to their role in HCV entry and impact on potential vaccine design and new antivirals.
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Affiliation(s)
- Abdul Ghafoor Khan
- Center for Advanced Biotechnology and Medicine, Department of Chemistry and Chemical Biology, Rutgers University, 679 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Matthew T Miller
- Center for Advanced Biotechnology and Medicine, Department of Chemistry and Chemical Biology, Rutgers University, 679 Hoes Lane West, Piscataway, NJ 08854, USA
| | - Joseph Marcotrigiano
- Center for Advanced Biotechnology and Medicine, Department of Chemistry and Chemical Biology, Rutgers University, 679 Hoes Lane West, Piscataway, NJ 08854, USA.
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Li Y, Pierce BG, Wang Q, Keck ZY, Fuerst TR, Foung SKH, Mariuzza RA. Structural basis for penetration of the glycan shield of hepatitis C virus E2 glycoprotein by a broadly neutralizing human antibody. J Biol Chem 2015; 290:10117-25. [PMID: 25737449 DOI: 10.1074/jbc.m115.643528] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Indexed: 12/13/2022] Open
Abstract
Hepatitis C virus (HCV) is a major cause of liver cirrhosis and hepatocellular carcinoma. A challenge for HCV vaccine development is to identify conserved epitopes able to elicit protective antibodies against this highly diverse virus. Glycan shielding is a mechanism by which HCV masks such epitopes on its E2 envelope glycoprotein. Antibodies to the E2 region comprising residues 412-423 (E2(412-423)) have broadly neutralizing activities. However, an adaptive mutation in this linear epitope, N417S, is associated with a glycosylation shift from Asn-417 to Asn-415 that enables HCV to escape neutralization by mAbs such as HCV1 and AP33. By contrast, the human mAb HC33.1 can neutralize virus bearing the N417S mutation. To understand how HC33.1 penetrates the glycan shield created by the glycosylation shift to Asn-415, we determined the structure of this broadly neutralizing mAb in complex with its E2(412-423) epitope to 2.0 Å resolution. The conformation of E2(412-423) bound to HC33.1 is distinct from the β-hairpin conformation of this peptide bound to HCV1 or AP33, because of disruption of the β-hairpin through interactions with the unusually long complementarity-determining region 3 of the HC33.1 heavy chain. Whereas Asn-415 is buried by HCV1 and AP33, it is solvent-exposed in the HC33.1-E2(412-423) complex, such that glycosylation of Asn-415 would not prevent antibody binding. Furthermore, our results highlight the structural flexibility of the E2(412-423) epitope, which may serve as an immune evasion strategy to impede induction of antibodies targeting this site by reducing its antigenicity.
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Affiliation(s)
- Yili Li
- From the University of Maryland Institute for Bioscience and Biotechnology Research, W. M. Keck Laboratory for Structural Biology, Rockville, Maryland 20850, the Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, and
| | - Brian G Pierce
- From the University of Maryland Institute for Bioscience and Biotechnology Research, W. M. Keck Laboratory for Structural Biology, Rockville, Maryland 20850
| | - Qian Wang
- From the University of Maryland Institute for Bioscience and Biotechnology Research, W. M. Keck Laboratory for Structural Biology, Rockville, Maryland 20850, the Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, and
| | - Zhen-Yong Keck
- the Department of Pathology, Stanford University School of Medicine, Stanford, California 94304
| | - Thomas R Fuerst
- From the University of Maryland Institute for Bioscience and Biotechnology Research, W. M. Keck Laboratory for Structural Biology, Rockville, Maryland 20850, the Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, and
| | - Steven K H Foung
- the Department of Pathology, Stanford University School of Medicine, Stanford, California 94304
| | - Roy A Mariuzza
- From the University of Maryland Institute for Bioscience and Biotechnology Research, W. M. Keck Laboratory for Structural Biology, Rockville, Maryland 20850, the Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, and
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Identification, molecular cloning, and analysis of full-length hepatitis C virus transmitted/founder genotypes 1, 3, and 4. mBio 2015; 6:e02518. [PMID: 25714714 PMCID: PMC4358020 DOI: 10.1128/mbio.02518-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Hepatitis C virus (HCV) infection is characterized by persistent replication of a complex mixture of viruses termed a “quasispecies.” Transmission is generally associated with a stringent population bottleneck characterized by infection by limited numbers of “transmitted/founder” (T/F) viruses. Characterization of T/F genomes of human immunodeficiency virus type 1 (HIV-1) has been integral to studies of transmission, immunopathogenesis, and vaccine development. Here, we describe the identification of complete T/F genomes of HCV by single-genome sequencing of plasma viral RNA from acutely infected subjects. A total of 2,739 single-genome-derived amplicons comprising 10,966,507 bp from 18 acute-phase and 11 chronically infected subjects were analyzed. Acute-phase sequences diversified essentially randomly, except for the poly(U/UC) tract, which was subject to polymerase slippage. Fourteen acute-phase subjects were productively infected by more than one genetically distinct virus, permitting assessment of recombination between replicating genomes. No evidence of recombination was found among 1,589 sequences analyzed. Envelope sequences of T/F genomes lacked transmission signatures that could distinguish them from chronic infection viruses. Among chronically infected subjects, higher nucleotide substitution rates were observed in the poly(U/UC) tract than in envelope hypervariable region 1. Fourteen full-length molecular clones with variable poly(U/UC) sequences corresponding to seven genotype 1a, 1b, 3a, and 4a T/F viruses were generated. Like most unadapted HCV clones, T/F genomes did not replicate efficiently in Huh 7.5 cells, indicating that additional cellular factors or viral adaptations are necessary for in vitro replication. Full-length T/F HCV genomes and their progeny provide unique insights into virus transmission, virus evolution, and virus-host interactions associated with immunopathogenesis. Hepatitis C virus (HCV) infects 2% to 3% of the world’s population and exhibits extraordinary genetic diversity. This diversity is mirrored by HIV-1, where characterization of transmitted/founder (T/F) genomes has been instrumental in studies of virus transmission, immunopathogenesis, and vaccine development. Here, we show that despite major differences in genome organization, replication strategy, and natural history, HCV (like HIV-1) diversifies essentially randomly early in infection, and as a consequence, sequences of actual T/F viruses can be identified. This allowed us to capture by molecular cloning the full-length HCV genomes that are responsible for infecting the first hepatocytes and eliciting the initial immune responses, weeks before these events could be directly analyzed in human subjects. These findings represent an enabling experimental strategy, not only for HCV and HIV-1 research, but also for other RNA viruses of medical importance, including West Nile, chikungunya, dengue, Venezuelan encephalitis, and Ebola viruses.
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The mechanism of HCV entry into host cells. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2014; 129:63-107. [PMID: 25595801 DOI: 10.1016/bs.pmbts.2014.10.003] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Hepatitis C virus (HCV) is an enveloped, positive strand RNA virus classified within the Flaviviridae family and is a major cause of liver disease worldwide. HCV life cycle and propagation are tightly linked to several aspects of lipid metabolism. HCV propagation depends on and also shapes several aspects of lipid metabolism such as cholesterol uptake and efflux through different lipoprotein receptors during its entry into cells, lipid metabolism modulating HCV genome replication, lipid droplets acting as a platform for recruitment of viral components, and very low density lipoprotein assembly pathway resulting in incorporation of neutral lipids and apolipoproteins into viral particles. During the first steps of infection, HCV enters hepatocytes through a multistep and slow process. The initial capture of HCV particles by glycosaminoglycans and/or lipoprotein receptors is followed by coordinated interactions with the scavenger receptor class B type I, a major receptor of high-density lipoprotein, the CD81 tetraspanin, and the tight junction proteins Claudin-1 and Occludin. This tight concert of receptor interactions ultimately leads to uptake and cellular internalization of HCV through a process of clathrin-dependent endocytosis. Over the years, the identification of the HCV entry receptors and cofactors has led to a better understanding of HCV entry and of the narrow tropism of HCV for the liver. Yet, the role of the two HCV envelope glycoproteins, E1 and E2, remains ill-defined, particularly concerning their involvement in the membrane fusion process. Here, we review the current knowledge and advances addressing the mechanism of HCV cell entry within hepatocytes and we highlight the challenges that remain to be addressed.
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Gededzha MP, Mphahlele MJ, Selabe SG. Characterization of HCV genotype 5a envelope proteins: implications for vaccine development and therapeutic entry target. HEPATITIS MONTHLY 2014; 14:e23660. [PMID: 25598792 PMCID: PMC4286708 DOI: 10.5812/hepatmon.23660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 10/08/2014] [Accepted: 10/26/2014] [Indexed: 12/11/2022]
Abstract
BACKGROUND Hepatitis C virus (HCV) is one of the major causes of cirrhosis and hepatocellular carcinoma with an estimation of 185 million people with infection. The E2 is the main target for neutralizing antibody responses and the variation of this region is related to maintenance of persistent infection by emerging escape variants and subsequent development of chronic infection. While both E1 and E2 are hypervariable in nature, it is difficult to design vaccines or therapeutic drugs against them. OBJECTIVES The objective of this study was to characterize genotype 5a E1 and E2 sequences to determine possible glycosylation sites, conserved B-cell epitopes and peptides in HCV that could be useful targets in design of vaccine and entry inhibitors. PATIENTS AND METHODS This study was conducted through PCR amplification of E1 and E2 regions, sequencing, prediction of B-cell epitopes, analysis of N-linked glycosylation and peptide design in 18 samples of HCV genotype 5a from South African. RESULTS Differences in the probability of glycosylation in E1 and E2 regions were observed in this study. Three conserved antigenic B-cell epitopes were predicted in the E2 regions and also 11 short peptides were designed from the highly conserved residues. CONCLUSIONS This study provided conserved B-cell epitopes and peptides that can be useful for designing entry inhibitors and vaccines able to cover a global population, especially where genotype 5a is common.
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Affiliation(s)
- Maemu Petronella Gededzha
- Department of Virology, HIV and Hepatitis Research Unit, University of Limpopo, Medunsa Campus/National Health Laboratory Service, Pretoria, South Africa
- Corresponding Author: Maemu Petronella Gededzha, Department of Virology, HIV and Hepatitis Research Unit, University of Limpopo, Medunsa Campus/National Health Laboratory Service, Pretoria, South Africa. Tel: +27-125213631, Fax: +27-125215794, E-mail:
| | - Maphahlanganye Jeffrey Mphahlele
- Department of Virology, HIV and Hepatitis Research Unit, University of Limpopo, Medunsa Campus/National Health Laboratory Service, Pretoria, South Africa
| | - Selokela Gloria Selabe
- Department of Virology, HIV and Hepatitis Research Unit, University of Limpopo, Medunsa Campus/National Health Laboratory Service, Pretoria, South Africa
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Chen PC, Chuang PK, Chen CH, Chan YT, Chen JR, Lin SW, Ma C, Hsu TL, Wong CH. Role of N-linked glycans in the interactions of recombinant HCV envelope glycoproteins with cellular receptors. ACS Chem Biol 2014; 9:1437-43. [PMID: 24766301 DOI: 10.1021/cb500121c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Hepatitis C virus (HCV) infection is a major cause of chronic hepatitis and hepatocellular carcinoma. It infects human liver cells through several cellular protein receptors including CD81, SR-BI, claudin-1, and occludin. Previous reports also show that lectin receptors can mediate HCV recognition and entry. The envelope proteins of HCV (E1 and E2) are heavily glycosylated, further indicating the possible roles of lectin receptor-virus interaction in HCV infection. However, there is limited study investigating the relationship of HCV envelope glycoproteins and lectin as well as non-lectin receptors. Here we used surface plasmon resonance to examine the binding affinity of different glycoforms of recombinant HCV envelope protein to receptors and inspected the infectivity and assembly of HCV pseudoparticles composed of different glycoforms of envelope proteins. Our results indicated that DC-SIGN, L-SIGN, and Langerin had higher affinity to recombinant HCV envelope proteins in the presence of calcium ions than non-lectin receptors, and envelope proteins with Man8/9 N-glycans showed approximate 10-fold better binding to lectin receptors than envelope proteins with Man5 and complex type N-glycans. Interestingly, comparing among glycoforms, recombinant envelope proteins with Man5 N-glycans showed the highest binding affinity when interacting with non-lectin receptors. In summary, the glycans on HCV envelope protein play a modulatory role in HCV assembly and infection and direct HCV-receptor interaction, which mediates viral entry in different cells. Receptors with high affinity to HCV envelope proteins may be considered as targets for development of a therapeutic strategy against HCV.
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Affiliation(s)
- Po-Chang Chen
- Institute
of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Po-Kai Chuang
- Institute
of Basic Medical Sciences, National Cheng Kung University, Tainan, Taiwan
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Hamed MR, Brown RJ, Zothner C, Urbanowicz RA, Mason CP, Krarup A, McClure CP, Irving WL, Ball JK, Harris M, Hickling TP, Tarr AW. Recombinant human L-ficolin directly neutralizes hepatitis C virus entry. J Innate Immun 2014; 6:676-84. [PMID: 24854201 PMCID: PMC6741592 DOI: 10.1159/000362209] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Revised: 03/16/2014] [Accepted: 03/16/2014] [Indexed: 12/25/2022] Open
Abstract
L-ficolin is a soluble pattern recognition molecule expressed by the liver that contributes to innate immune defense against microorganisms. It is well described that binding of L-ficolin to specific pathogen-associated molecular patterns activates the lectin complement pathway, resulting in opsonization and lysis of pathogens. In this study, we demonstrated that in addition to this indirect effect, L-ficolin has a direct neutralizing effect against hepatitis C virus (HCV) entry. Specific, dose-dependent binding of recombinant L-ficolin to HCV glycoproteins E1 and E2 was observed. This interaction was inhibited by soluble L-ficolin ligands. Interaction of L-ficolin with E1 and E2 potently inhibited entry of retroviral pseudoparticles bearing these glycoproteins. L-ficolin also inhibited entry of cell-cultured HCV in a calcium-dependent manner. Neutralizing concentrations of L-ficolin were found to be circulating in the serum of HCV-infected individuals. This is the first description of direct neutralization of HCV entry by a ficolin and highlights a novel role for L-ficolin as a virus entry inhibitor.
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Affiliation(s)
- Mohamed R. Hamed
- School of Life Sciences, and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, UK
- Medical Microbiology and Immunology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Richard J.P. Brown
- School of Life Sciences, and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, UK
| | - Carsten Zothner
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Richard A. Urbanowicz
- School of Life Sciences, and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, UK
| | - Christopher P. Mason
- School of Life Sciences, and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, UK
| | - Anders Krarup
- Biochemistry Department, University of Oxford, Oxford, UK
| | - C. Patrick McClure
- School of Life Sciences, and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, UK
| | - William L. Irving
- School of Life Sciences, and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, UK
| | - Jonathan K. Ball
- School of Life Sciences, and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, UK
| | - Mark Harris
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Timothy P. Hickling
- School of Life Sciences, and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, UK
| | - Alexander W. Tarr
- School of Life Sciences, and Nottingham Digestive Diseases Biomedical Research Unit, University of Nottingham, Nottingham, UK
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Pfaender S, Brown RJ, Pietschmann T, Steinmann E. Natural reservoirs for homologs of hepatitis C virus. Emerg Microbes Infect 2014; 3:e21. [PMID: 26038514 PMCID: PMC3974340 DOI: 10.1038/emi.2014.19] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 01/07/2014] [Accepted: 01/22/2014] [Indexed: 12/31/2022]
Abstract
Hepatitis C virus is considered a major public health problem, infecting 2%–3% of the human population. Hepatitis C virus infection causes acute and chronic liver disease, including chronic hepatitis, cirrhosis and hepatocellular carcinoma. In fact, hepatitis C virus infection is the most frequent indication for liver transplantation and a vaccine is not available. Hepatitis C virus displays a narrow host species tropism, naturally infecting only humans, although chimpanzees are also susceptible to experimental infection. To date, there is no evidence for an animal reservoir of viruses closely related to hepatitis C virus which may have crossed the species barrier to cause disease in humans and resulted in the current pandemic. In fact, due to this restricted host range, a robust immunocompetent small animal model is still lacking, hampering mechanistic analysis of virus pathogenesis, immune control and prophylactic vaccine development. Recently, several studies discovered new viruses related to hepatitis C virus, belonging to the hepaci- and pegivirus genera, in small wild mammals (rodents and bats) and domesticated animals which live in close contact with humans (dogs and horses). Genetic and biological characterization of these newly discovered hepatitis C virus-like viruses infecting different mammals will contribute to our understanding of the origins of hepatitis C virus in humans and enhance our ability to study pathogenesis and immune responses using tractable animal models. In this review article, we start with an introduction on the genetic diversity of hepatitis C virus and then focus on the newly discovered viruses closely related to hepatitis C virus. Finally, we discuss possible theories about the origin of this important viral human pathogen.
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Affiliation(s)
- Stephanie Pfaender
- Institute for Experimental Virology, Twincore Centre of Experimental and Clinical Infection Research; a joint venture between the Hannover Medical School and the Helmholtz Centre for Infection Research , Hannover 30625, Germany
| | - Richard Jp Brown
- Institute for Experimental Virology, Twincore Centre of Experimental and Clinical Infection Research; a joint venture between the Hannover Medical School and the Helmholtz Centre for Infection Research , Hannover 30625, Germany
| | - Thomas Pietschmann
- Institute for Experimental Virology, Twincore Centre of Experimental and Clinical Infection Research; a joint venture between the Hannover Medical School and the Helmholtz Centre for Infection Research , Hannover 30625, Germany
| | - Eike Steinmann
- Institute for Experimental Virology, Twincore Centre of Experimental and Clinical Infection Research; a joint venture between the Hannover Medical School and the Helmholtz Centre for Infection Research , Hannover 30625, Germany
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Ranjbar MM, Ghorban K, Alavian SM, Keyvani H, Dadmanesh M, Roayaei Ardakany A, Motedayen MH, Sazmand A. GB Virus C/Hepatitis G Virus Envelope Glycoprotein E2: Computational Molecular Features and Immunoinformatics Study. HEPATITIS MONTHLY 2013; 13:e15342. [PMID: 24403917 PMCID: PMC3877655 DOI: 10.5812/hepatmon.15342] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 12/01/2013] [Accepted: 12/01/2013] [Indexed: 12/11/2022]
Abstract
INTRODUCTION GB virus C (GBV-C) or hepatitis G virus (HGV) is an enveloped, RNA positive-stranded flavivirus-like particle. E2 envelope protein of GBV-C plays an important role in virus entry into the cytosol, genotyping and as a marker for diagnosing GBV-C infections. Also, there is discussion on relations between E2 protein and gp41 protein of HIV. The purposes of our study are to multi aspect molecular evaluation of GB virus C E2 protein from its characteristics, mutations, structures and antigenicity which would help to new directions for future researches. EVIDENCE ACQUISITION Briefly, steps followed here were; retrieving reference sequences of E2 protein, entropy plot evaluation for finding the mutational /conservative regions, analyzing potential Glycosylation, Phosphorylation and Palmitoylation sites, prediction of primary, secondary and tertiary structures, then amino acid distributions and transmembrane topology, prediction of T and B cell epitopes, and finally visualization of epitopes and variations regions in 3D structure. RESULTS Based on the entropy plot, 3 hypervariable regions (HVR) observed along E2 protein located in residues 133-135, 256-260 and 279-281. Analyzing primary structure of protein sequence revealed basic nature, instability, and low hydrophilicity of this protein. Transmembrane topology prediction showed that residues 257-270 presented outside, while residues 234- 256 and 271-293 were transmembrane regions. Just one N-glycosylation site, 5 potential phosphorylated peptides and two palmitoylation were found. Secondary structure revealed that this protein has 6 α-helix, 12 β-strand 17 Coil structures. Prediction of T-cell epitopes based on HLA-A*02:01 showed that epitope NH3-LLLDFVFVL-COOH is the best antigen icepitope. Comparative analysis for consensus B-cell epitopes regarding transmembrane topology, based on physico-chemical and machine learning approaches revealed that residue 231- 296 (NH2- EARLVPLILLLLWWWVNQLAVLGLPAVEAAVAGEVFAGPALSWCLGLPVVSMILGLANLVLYFRWL-COOH) is most effective and probable B cell epitope for E2 protein. CONCLUSIONS The comprehensive analysis of a protein with important roles has never been easy, and in case of E2 envelope glycoprotein of HGV, there is no much data on its molecular and immunological features, clinical significance and its pathogenic potential in hepatitis or any other GBV-C related diseases. So, results of the present study may explain some structural, physiological and immunological functions of this protein in GBV-C, as well as designing new diagnostic kits and besides, help to better understandingE2 protein characteristic and other members of Flavivirus family, especially HCV.
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Affiliation(s)
| | - Khodayar Ghorban
- Department of Immunology, School of Medicine, AJA University of Medical Sciences, Tehran, IR Iran
| | - Seyed Moayed Alavian
- Middle East Liver Diseases Center (MELD), Tehran, IR Iran
- Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Baqiyatallh University of Medical Sciences, Tehran, IR Iran
- Corresponding Author: Seyed Moayed Alavian, Baqiyatallah Research Center for Gastroenterology and Liver Diseases, Baqiyatallh University of Medical Sciences, Tehran, IR Iran. Tel/Fax: +98-2188945186, E-mail:
| | - Hossein Keyvani
- Department of Virology, Tehran University of Medical Sciences, Tehran, IR Iran
| | - Maryam Dadmanesh
- Department of Infectious Diseases, School of Medicine, AJA University of Medical Sciences, Tehran, IR Iran
| | | | | | - Alireza Sazmand
- Department of Agriculture, Payame Noor University, Yazd, IR Iran
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Kachko A, Loesgen S, Shahzad-Ul-Hussan S, Tan W, Zubkova I, Takeda K, Wells F, Rubin S, Bewley CA, Major ME. Inhibition of hepatitis C virus by the cyanobacterial protein Microcystis viridis lectin: mechanistic differences between the high-mannose specific lectins MVL, CV-N, and GNA. Mol Pharm 2013; 10:4590-4602. [PMID: 24152340 DOI: 10.1021/mp400399b] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Plant or microbial lectins are known to exhibit potent antiviral activities against viruses with glycosylated surface proteins, yet the mechanism(s) by which these carbohydrate-binding proteins exert their antiviral activities is not fully understood. Hepatitis C virus (HCV) is known to possess glycosylated envelope proteins (gpE1E2) and to be potently inhibited by lectins. Here, we tested in detail the antiviral properties of the newly discovered Microcystis viridis lectin (MVL) along with cyanovirin-N (CV-N) and Galanthus nivalis agglutinin (GNA) against cell culture HCV, as well as their binding properties toward viral particles, target cells, and recombinant HCV glycoproteins. Using infectivity assays, CV-N, MVL, and GNA inhibited HCV with IC50 values of 0.6 nM, 30.4 nM, and 11.1 nM, respectively. Biolayer interferometry analysis demonstrated a higher affinity of GNA to immobilized recombinant HCV glycoproteins compared to CV-N and MVL. Complementary studies, including fluorescence-activated cell sorting (FACS) analysis, confocal microscopy, and pre- and post-virus binding assays, showed a complex mechanism of inhibition for CV-N and MVL that includes both viral and cell association, while GNA functions by binding directly to the viral particle. Combinations of GNA with CV-N or MVL in HCV infection studies revealed synergistic inhibitory effects, which can be explained by different glycan recognition profiles of the mainly high-mannoside specific lectins, and supports the hypothesis that these lectins inhibit through different and complex modes of action. Our findings provide important insights into the mechanisms by which lectins inhibit HCV infection. Overall, the data suggest MVL and CV-N have the potential for toxicity due to interactions with cellular proteins while GNA may be a better therapeutic agent due to specificity for the HCV gpE1E2.
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Affiliation(s)
- Alla Kachko
- Laboratory of Hepatitis Viruses, Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 USA
| | - Sandra Loesgen
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda Maryland 20892, USA
| | - Syed Shahzad-Ul-Hussan
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda Maryland 20892, USA.,Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda Maryland 20892, USA
| | - Wendy Tan
- Laboratory of Hepatitis Viruses, Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 USA
| | - Iryna Zubkova
- Laboratory of Hepatitis Viruses, Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 USA
| | - Kazuyo Takeda
- Microscopy and Imaging Core Facility, Center for Biologics Evaluation and Research, US Food and Drug Administration, Bethesda, MD 20892. USA
| | - Frances Wells
- Laboratory of Hepatitis Viruses, Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 USA
| | - Steven Rubin
- Laboratory of Method Development, Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892. USA
| | - Carole A Bewley
- Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda Maryland 20892, USA
| | - Marian E Major
- Laboratory of Hepatitis Viruses, Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 USA
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Characterization of hepatitis C virus intra- and intergenotypic chimeras reveals a role of the glycoproteins in virus envelopment. J Virol 2013; 87:13297-306. [PMID: 24089562 DOI: 10.1128/jvi.01708-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Hepatitis C virus (HCV) is highly variable and associated with chronic liver disease. Viral isolates are grouped into seven genotypes (GTs). Accumulating evidence indicates that viral determinants in the core to NS2 proteins modulate the efficiency of virus production. However, the role of the glycoproteins E1 and E2 in this process is currently poorly defined. Therefore, we constructed chimeric viral genomes to explore the role of E1 and E2 in HCV assembly. Comparison of the kinetics and efficiency of particle production by intragenotypic chimeras highlighted core and p7 as crucial determinants for efficient virion release. Glycoprotein sequences, however, had only a minimal impact on this process. In contrast, in the context of intergenotypic HCV chimeras, HCV assembly was profoundly influenced by glycoprotein genes. On the one hand, insertion of GT1a-derived (H77) E1-E2 sequences into a chimeric GT2a virus (Jc1) strongly suppressed virus production. On the other hand, replacement of H77 glycoproteins within the GT1a-GT2a chimeric genome H77/C3 by GT2a-derived (Jc1) E1-E2 increased infectious particle production. Thus, within intergenotypic chimeras, glycoprotein features strongly modulate virus production. Replacement of Jc1 glycoprotein genes by H77-derived E1-E2 did not grossly affect subcellular localization of core, E2, and NS2. However, it caused an accumulation of nonenveloped core protein and increased abundance of nonenveloped core protein structures with slow sedimentation. These findings reveal an important role for the HCV glycoproteins E1 and E2 in membrane envelopment, which likely depends on a genotype-specific interplay with additional viral factors.
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47
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Omran MH, Nabil W, Youssef SS, El-Sayed M, El Awady MK. Heterogeneity and new epitopes of hepatitis C virus genotype 4. HEPATITIS MONTHLY 2013; 13:e10521. [PMID: 24130599 PMCID: PMC3796197 DOI: 10.5812/hepatmon.10521] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 04/14/2013] [Accepted: 06/20/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND Hepatitis C virus (HCV) was found to have a major role in human liver disease by its ability to face the host-cell defenses and the immune system. Heterogeneity of HCV was the key for its adaptation to its host and represented a significant hurdle for the development of both effective vaccines as well as for novel therapeutic interventions. OBJECTIVES Due to the heterogeneity of HCV virus because of both high replication and high mutation rate in vivo, this study was conducted to analyze different isolates of Egyptian patients of genotype 4, of the most mutant regions of the virus (E1 and E2) as they played an important role in viral persistence by escaping from the immune system of the host body. PATIENTS AND METHODS This study was conducted through PCR amplification of E1 and E2 regions, sequencing and phylogenetic analysis, calculating synonyms and non-synonyms substitutions, finding the possible glycosylation sites and different epitope domains. RESULTS The present work figured out that the heterogeneity of the quasispecies of our local strains 4a was high showing up 15% diversity. This study also showed four glycosylation sites that play an important role in the entry of the virus and protein folding. Besides, different epitpoes were identified in different regions of the E1 and E2 domains; a finding which would help in determining the neutralizing and non- neutralizing antibodies. CONCLUSIONS This study would help in understanding the driving forces of genetic diversity and would be fundamental for representing potential candidate targets for antibodies and the development of vaccine trials.
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Affiliation(s)
- Moataza H. Omran
- Microbial Biotechnology Department, Genetic Engineering Division, National Research Centre, Dokki Cairo, Egypt
- Corresponding author: Moataza H. Omran, Microbial Biotechnology Department, Genetic Engineering Division, National Research Centre, Dokki Cairo, Egypt. Tel: +20-1223735450, Fax: +20-233370931, E-mail: ,
| | - Wael Nabil
- Microbial Biotechnology Department, Genetic Engineering Division, National Research Centre, Dokki Cairo, Egypt
| | - Samar S. Youssef
- Microbial Biotechnology Department, Genetic Engineering Division, National Research Centre, Dokki Cairo, Egypt
| | - Mervat El-Sayed
- Chemistry Department, Faculty of Science, Cairo University, Dokki Cairo, Egypt
| | - Mostafa K. El Awady
- Microbial Biotechnology Department, Genetic Engineering Division, National Research Centre, Dokki Cairo, Egypt
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48
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Takebe Y, Saucedo CJ, Lund G, Uenishi R, Hase S, Tsuchiura T, Kneteman N, Ramessar K, Tyrrell DLJ, Shirakura M, Wakita T, McMahon JB, O'Keefe BR. Antiviral lectins from red and blue-green algae show potent in vitro and in vivo activity against hepatitis C virus. PLoS One 2013; 8:e64449. [PMID: 23700478 PMCID: PMC3660260 DOI: 10.1371/journal.pone.0064449] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 04/15/2013] [Indexed: 12/17/2022] Open
Abstract
Hepatitis C virus (HCV) infection is a significant public health problem with over 170,000,000 chronic carriers and infection rates increasing worldwide. Chronic HCV infection is one of the leading causes of hepatocellular carcinoma which was estimated to result in ∼10,000 deaths in the United States in the year 2011. Current treatment options for HCV infection are limited to PEG-ylated interferon alpha (IFN-α), the nucleoside ribavirin and the recently approved HCV protease inhibitors telaprevir and boceprevir. Although showing significantly improved efficacy over the previous therapies, treatment with protease inhibitors has been shown to result in the rapid emergence of drug-resistant virus. Here we report the activity of two proteins, originally isolated from natural product extracts, which demonstrate low or sub-nanomolar in vitro activity against both genotype I and genotype II HCV. These proteins inhibit viral infectivity, binding to the HCV envelope glycoproteins E1 and E2 and block viral entry into human hepatocytes. In addition, we demonstrate that the most potent of these agents, the protein griffithsin, is readily bioavailable after subcutaneous injection and shows significant in vivo efficacy in reducing HCV viral titers in a mouse model system with engrafted human hepatocytes. These results indicate that HCV viral entry inhibitors can be an effective component of anti-HCV therapy and that these proteins should be studied further for their therapeutic potential.
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Affiliation(s)
- Yutaka Takebe
- AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Carrie J. Saucedo
- Molecular Targets Laboratory, SAIC-Frederick, Frederick, Maryland, United States of America
| | | | - Rie Uenishi
- AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Saiki Hase
- AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takayo Tsuchiura
- AIDS Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | | | - Koreen Ramessar
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | | | | | - Takaji Wakita
- Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - James B. McMahon
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Barry R. O'Keefe
- Molecular Targets Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
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49
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Park JH, Jee MH, Kwon OS, Keum SJ, Jang SK. Infectivity of hepatitis C virus correlates with the amount of envelope protein E2: development of a new aptamer-based assay system suitable for measuring the infectious titer of HCV. Virology 2013; 439:13-22. [PMID: 23485371 DOI: 10.1016/j.virol.2013.01.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Revised: 12/28/2012] [Accepted: 01/17/2013] [Indexed: 12/13/2022]
Abstract
Various forms of hepatitis C virus (HCV)-related particles are produced from HCV-infected cells. Measuring infectivity of a HCV sample with the conventional 'foci counting method' is laborious and time-consuming. Moreover, the infectivity of a HCV sample does not correlate with the amount of viral RNA that can be measured by real-time RT-PCR. Here we report a new assay suitable for quantifying infectious HCV particles using aptamers against HCV E2, which is named 'Enzyme Linked Apto-Sorbent Assay (ELASA)'. The readout value of HCV ELASA linearly correlates with the infectious dose of an HCV sample, but not with the amount of HCV RNA. We also demonstrated that the activities of anti-HCV drugs can be monitored by HCV ELASA. Therefore, HCV ELASA is a quick-and-easy method to quantify infectious units of HCV stocks and to monitor efficacies of potential anti-HCV drugs.
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Affiliation(s)
- Ji Hoon Park
- Molecular Virology Laboratory, POSTECH Biotech Center, Department of Life Science, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang, Kyungbuk 790-784, Republic of Korea
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50
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Carlsen THR, Scheel TKH, Ramirez S, Foung SKH, Bukh J. Characterization of hepatitis C virus recombinants with chimeric E1/E2 envelope proteins and identification of single amino acids in the E2 stem region important for entry. J Virol 2013; 87:1385-99. [PMID: 23152512 PMCID: PMC3554168 DOI: 10.1128/jvi.00684-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2012] [Accepted: 10/30/2012] [Indexed: 02/07/2023] Open
Abstract
The hepatitis C virus (HCV) envelope proteins E1 and E2 play a key role in host cell entry and represent important targets for vaccine and drug development. Here, we characterized HCV recombinants with chimeric E1/E2 complexes in vitro. Using genotype 1a/2a JFH1-based recombinants expressing 1a core-NS2, we exchanged E2 with functional isolate sequences of genotypes 1a (alternative isolate), 1b, and 2a. While the 1a-E2 exchange did not impact virus viability, the 2a-E2 recombinant was nonviable. After E2 exchange from three 1b isolates, long delays were observed before spread of infection. For recovered 1b-E2 recombinants, single E2 stem region amino acid changes were identified at residues 706, 707, and 710. In reverse genetic studies, these mutations increased infectivity titers by ~100-fold, apparently without influencing particle stability or cell binding although introducing slight decrease in particle density. In addition, the 1b-E2 exchange led to a decrease in secreted core protein of 25 to 50%, which was further reduced by the E2 stem region mutations. These findings indicated that compensatory mutations permitted robust infectious virus production, without increasing assembly/release. Studies of E1/E2 heterodimerization showed no differences in intracellular E1/E2 interaction for chimeric constructs with or without E2 stem region mutations. Interestingly, the E2 stem region mutations allowed efficient entry, which was verified in 1a-E1/1b-E2 HCV pseudoparticle assays. A CD81 inhibition assay indicated that the mutations influenced a late step of the HCV entry pathway. Overall, this study identified specific amino acids in the E2 stem region of importance for HCV entry and for production of infectious virus particles.
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Affiliation(s)
- Thomas H. R. Carlsen
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Troels K. H. Scheel
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Santseharay Ramirez
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Steven K. H. Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Jens Bukh
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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