1
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Stejskal L, Kalemera MD, Lewis CB, Palor M, Walker L, Daviter T, Lees WD, Moss DS, Kremyda-Vlachou M, Kozlakidis Z, Gallo G, Bailey D, Rosenberg W, Illingworth CJR, Shepherd AJ, Grove J. An entropic safety catch controls hepatitis C virus entry and antibody resistance. eLife 2022; 11:e71854. [PMID: 35796426 PMCID: PMC9333995 DOI: 10.7554/elife.71854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 06/28/2022] [Indexed: 11/24/2022] Open
Abstract
E1 and E2 (E1E2), the fusion proteins of Hepatitis C Virus (HCV), are unlike that of any other virus yet described, and the detailed molecular mechanisms of HCV entry/fusion remain unknown. Hypervariable region-1 (HVR-1) of E2 is a putative intrinsically disordered protein tail. Here, we demonstrate that HVR-1 has an autoinhibitory function that suppresses the activity of E1E2 on free virions; this is dependent on its conformational entropy. Thus, HVR-1 is akin to a safety catch that prevents premature triggering of E1E2 activity. Crucially, this mechanism is turned off by host receptor interactions at the cell surface to allow entry. Mutations that reduce conformational entropy in HVR-1, or genetic deletion of HVR-1, turn off the safety catch to generate hyper-reactive HCV that exhibits enhanced virus entry but is thermally unstable and acutely sensitive to neutralising antibodies. Therefore, the HVR-1 safety catch controls the efficiency of virus entry and maintains resistance to neutralising antibodies. This discovery provides an explanation for the ability of HCV to persist in the face of continual immune assault and represents a novel regulatory mechanism that is likely to be found in other viral fusion machinery.
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Affiliation(s)
- Lenka Stejskal
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
| | - Mphatso D Kalemera
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Charlotte B Lewis
- MRC-University of Glasgow Centre for Virus ResearchGlasgowUnited Kingdom
| | - Machaela Palor
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Lucas Walker
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
| | - Tina Daviter
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
- Shared Research Facilities, The Institute of Cancer ResearchLondonUnited Kingdom
| | - William D Lees
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
| | - David S Moss
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
| | | | - Zisis Kozlakidis
- International Agency for Research on Cancer, World Health OrganizationLyonFrance
| | | | | | - William Rosenberg
- Division of Medicine, Institute for Liver and Digestive Health, University College LondonLondonUnited Kingdom
| | - Christopher JR Illingworth
- MRC-University of Glasgow Centre for Virus ResearchGlasgowUnited Kingdom
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
- Institut für Biologische Physik, Universität zu KölnCologneGermany
- MRC Biostatistics Unit, University of CambridgeCambridgeUnited Kingdom
| | - Adrian J Shepherd
- Institute of Structural and Molecular Biology, Birkbeck CollegeLondonUnited Kingdom
| | - Joe Grove
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College LondonLondonUnited Kingdom
- MRC-University of Glasgow Centre for Virus ResearchGlasgowUnited Kingdom
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2
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Browning AP, Ansari N, Drovandi C, Johnston APR, Simpson MJ, Jenner AL. Identifying cell-to-cell variability in internalization using flow cytometry. J R Soc Interface 2022; 19:20220019. [PMID: 35611619 PMCID: PMC9131125 DOI: 10.1098/rsif.2022.0019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 04/21/2022] [Indexed: 12/23/2022] Open
Abstract
Biological heterogeneity is a primary contributor to the variation observed in experiments that probe dynamical processes, such as the internalization of material by cells. Given that internalization is a critical process by which many therapeutics and viruses reach their intracellular site of action, quantifying cell-to-cell variability in internalization is of high biological interest. Yet, it is common for studies of internalization to neglect cell-to-cell variability. We develop a simple mathematical model of internalization that captures the dynamical behaviour, cell-to-cell variation, and extrinsic noise introduced by flow cytometry. We calibrate our model through a novel distribution-matching approximate Bayesian computation algorithm to flow cytometry data of internalization of anti-transferrin receptor antibody in a human B-cell lymphoblastoid cell line. This approach provides information relating to the region of the parameter space, and consequentially the nature of cell-to-cell variability, that produces model realizations consistent with the experimental data. Given that our approach is agnostic to sample size and signal-to-noise ratio, our modelling framework is broadly applicable to identify biological variability in single-cell data from internalization assays and similar experiments that probe cellular dynamical processes.
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Affiliation(s)
- Alexander P. Browning
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia
- ARC Centre of Excellence for Mathematical and Statistical Frontiers, Queensland University of Technology, Brisbane, Australia
- QUT Centre for Data Science, Queensland University of Technology, Brisbane, Australia
| | - Niloufar Ansari
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Christopher Drovandi
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia
- ARC Centre of Excellence for Mathematical and Statistical Frontiers, Queensland University of Technology, Brisbane, Australia
- QUT Centre for Data Science, Queensland University of Technology, Brisbane, Australia
| | - Angus P. R. Johnston
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Matthew J. Simpson
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia
- QUT Centre for Data Science, Queensland University of Technology, Brisbane, Australia
| | - Adrianne L. Jenner
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Australia
- QUT Centre for Data Science, Queensland University of Technology, Brisbane, Australia
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3
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Augestad EH, Bukh J, Prentoe J. Hepatitis C virus envelope protein dynamics and the link to hypervariable region 1. Curr Opin Virol 2021; 50:69-75. [PMID: 34403905 DOI: 10.1016/j.coviro.2021.07.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/22/2021] [Accepted: 07/22/2021] [Indexed: 12/11/2022]
Abstract
Conformational dynamics of viral envelope proteins seem to be involved in mediating evasion from neutralizing antibodies (NAbs) by mechanisms that limit exposure of conserved protein motifs. For hepatitis C virus (HCV), molecular studies have only recently begun to unveil how such dynamics of the envelope protein heterodimer, E1/E2, are linked to viral entry and NAb evasion. Here, we review data suggesting that E1/E2 exists in an equilibrium between theoretical 'open' (NAb-sensitive) and 'closed' (NAb-resistant) conformational states. We describe how this equilibrium is influenced by viral sequence polymorphisms and that it is critically dependent on the N-terminal region of E2, termed hypervariable region 1 (HVR1). Finally, we discuss how it appears that the virus binding site for the HCV entry co-receptor CD81 is less available in 'closed' E1/E2 states and that NAb-resistant viruses require a more intricate entry pathway involving also the entry co-receptor, SR-BI.
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Affiliation(s)
- Elias H Augestad
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Copenhagen, Denmark; Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Copenhagen, Denmark; Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Copenhagen, Denmark; Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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4
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Olesen CH, Augestad EH, Troise F, Bukh J, Prentoe J. In vitro adaptation and characterization of attenuated hypervariable region 1 swap chimeras of hepatitis C virus. PLoS Pathog 2021; 17:e1009720. [PMID: 34280245 PMCID: PMC8321405 DOI: 10.1371/journal.ppat.1009720] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 07/29/2021] [Accepted: 06/15/2021] [Indexed: 12/18/2022] Open
Abstract
Hepatitis C virus (HCV) chronically infects 70 million people worldwide with an estimated annual disease-related mortality of 400,000. A vaccine could prevent spread of this pervasive human pathogen, but has proven difficult to develop, partly due to neutralizing antibody evasion mechanisms that are inherent features of the virus envelope glycoproteins, E1 and E2. A central actor is the E2 motif, hypervariable region 1 (HVR1), which protects several non-overlapping neutralization epitopes through an incompletely understood mechanism. Here, we show that introducing different HVR1-isolate sequences into cell-culture infectious JFH1-based H77 (genotype 1a) and J4 (genotype 1b) Core-NS2 recombinants can lead to severe viral attenuation. Culture adaptation of attenuated HVR1-swapped recombinants permitted us to identify E1/E2 substitutions at conserved positions both within and outside HVR1 that increased the infectivity of attenuated HVR1-swapped recombinants but were not adaptive for original recombinants. H77 recombinants with HVR1 from multiple other isolates consistently acquired substitutions at position 348 in E1 and position 385 in HVR1 of E2. Interestingly, HVR1-swapped J4 recombinants primarily acquired other substitutions: F291I (E1), F438V (E2), F447L/V/I (E2) and V710L (E2), indicating a different adaptation pathway. For H77 recombinants, the adaptive E1/E2 substitutions increased sensitivity to the neutralizing monoclonal antibodies AR3A and AR4A, whereas for J4 recombinants, they increased sensitivity to AR3A, while having no effect on sensitivity to AR4A. To evaluate effects of the substitutions on AR3A and AR4A binding, we performed ELISAs on extracted E1/E2 protein and performed immunoprecipitation of relevant viruses. However, extracted E1/E2 protein and immunoprecipitation of HCV particles only reproduced the neutralization phenotypes of the J4 recombinants. Finally, we found that the HVR1-swap E1/E2 substitutions decrease virus entry dependency on co-receptor SR-BI. Our study identifies E1/E2 positions that could be critical for intra-complex HVR1 interactions while emphasizing the need for developing novel tools for molecular studies of E1/E2 interactions.
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Affiliation(s)
- Christina Holmboe Olesen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elias H. Augestad
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Fulvia Troise
- Ceinge Biotecnologie Avanzate Via Gaetano Salvatore, Napoli, Italy
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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5
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Kalemera MD, Capella-Pujol J, Chumbe A, Underwood A, Bull RA, Schinkel J, Sliepen K, Grove J. Optimized cell systems for the investigation of hepatitis C virus E1E2 glycoproteins. J Gen Virol 2021; 102. [PMID: 33147126 PMCID: PMC8116788 DOI: 10.1099/jgv.0.001512] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Great strides have been made in understanding and treating hepatitis C virus (HCV) thanks to the development of various experimental systems including cell-culture-proficient HCV, the HCV pseudoparticle system and soluble envelope glycoproteins. The HCV pseudoparticle (HCVpp) system is a platform used extensively in studies of cell entry, screening of novel entry inhibitors, assessing the phenotypes of clinically observed E1 and E2 glycoproteins and, most pertinently, in characterizing neutralizing antibody breadth induced upon vaccination and natural infection in patients. Nonetheless, some patient-derived clones produce pseudoparticles that are either non-infectious or exhibit infectivity too low for meaningful phenotyping. The mechanisms governing whether any particular clone produces infectious pseudoparticles are poorly understood. Here we show that endogenous expression of CD81, an HCV receptor and a cognate-binding partner of E2, in producer HEK 293T cells is detrimental to the infectivity of recovered HCVpp for most strains. Many HCVpp clones exhibited increased infectivity or had their infectivity rescued when they were produced in 293T cells CRISPR/Cas9 engineered to ablate CD81 expression (293TCD81KO). Clones made in 293TCD81KO cells were antigenically very similar to their matched counterparts made parental cells and appear to honour the accepted HCV entry pathway. Deletion of CD81 did not appreciably increase the recovered titres of soluble E2 (sE2). However, we did, unexpectedly, find that monomeric sE2 made in 293T cells and Freestyle 293-F (293-F) cells exhibit important differences. We found that 293-F-produced sE2 harbours mostly complex-type glycans whilst 293T-produced sE2 displays a heterogeneous mixture of both complex-type glycans and high-mannose or hybrid-type glycans. Moreover, sE2 produced in 293T cells is antigenically superior; exhibiting increased binding to conformational antibodies and the large extracellular loop of CD81. In summary, this work describes an optimal cell line for the production of HCVpp and reveals that sE2 made in 293T and 293-F cells are not antigenic equals. Our findings have implications for functional studies of E1E2 and the production of candidate immunogens.
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Affiliation(s)
- Mphatso D Kalemera
- Institute of Immunity and Transplantation, Division of Infection and Immunity, The Royal Free Hospital, University College London, London, UK
| | - Joan Capella-Pujol
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Ana Chumbe
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Alexander Underwood
- Viral Immunology Systems Program, The Kirby Institute, School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Rowena A Bull
- Viral Immunology Systems Program, The Kirby Institute, School of Medical Sciences, Faculty of Medicine, The University of New South Wales, Sydney, Australia
| | - Janke Schinkel
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Kwinten Sliepen
- Department of Medical Microbiology, Amsterdam Infection & Immunity Institute, Amsterdam UMC, Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Joe Grove
- Institute of Immunity and Transplantation, Division of Infection and Immunity, The Royal Free Hospital, University College London, London, UK
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6
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Velázquez-Moctezuma R, Augestad EH, Castelli M, Holmboe Olesen C, Clementi N, Clementi M, Mancini N, Prentoe J. Mechanisms of Hepatitis C Virus Escape from Vaccine-Relevant Neutralizing Antibodies. Vaccines (Basel) 2021; 9:291. [PMID: 33804732 PMCID: PMC8004074 DOI: 10.3390/vaccines9030291] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/15/2021] [Accepted: 03/16/2021] [Indexed: 12/15/2022] Open
Abstract
Hepatitis C virus (HCV) is a major causative agent of acute and chronic hepatitis. It is estimated that 400,000 people die every year from chronic HCV infection, mostly from severe liver-related diseases such as cirrhosis and liver cancer. Although HCV was discovered more than 30 years ago, an efficient prophylactic vaccine is still missing. The HCV glycoprotein complex, E1/E2, is the principal target of neutralizing antibodies (NAbs) and, thus, is an attractive antigen for B-cell vaccine design. However, the high genetic variability of the virus necessitates the identification of conserved epitopes. Moreover, the high intrinsic mutational capacity of HCV allows the virus to continually escape broadly NAbs (bNAbs), which is likely to cause issues with vaccine-resistant variants. Several studies have assessed the barrier-to-resistance of vaccine-relevant bNAbs in vivo and in vitro. Interestingly, recent studies have suggested that escape substitutions can confer antibody resistance not only by direct modification of the epitope but indirectly through allosteric effects, which can be grouped based on the breadth of these effects on antibody susceptibility. In this review, we summarize the current understanding of HCV-specific NAbs, with a special focus on vaccine-relevant bNAbs and their targets. We highlight antibody escape studies pointing out the different methodologies and the escape mutations identified thus far. Finally, we analyze the antibody escape mechanisms of envelope protein escape substitutions and polymorphisms according to the most recent evidence in the HCV field. The accumulated knowledge in identifying bNAb epitopes as well as assessing barriers to resistance and elucidating relevant escape mechanisms may prove critical in the successful development of an HCV B-cell vaccine.
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Affiliation(s)
- Rodrigo Velázquez-Moctezuma
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
| | - Elias H. Augestad
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
| | - Matteo Castelli
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Christina Holmboe Olesen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
| | - Nicola Clementi
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Massimo Clementi
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Nicasio Mancini
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, 20132 Milano, Italy; (M.C.); (N.C.); (M.C.); (N.M.)
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, 2200 Copenhagen, Denmark; (R.V.-M.); (E.H.A.); (C.H.O.)
- Department of Infectious Diseases, Hvidovre Hospital, 2650 Hvidovre, Denmark
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7
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Padmanabhan P, Desikan R, Dixit NM. Targeting TMPRSS2 and Cathepsin B/L together may be synergistic against SARS-CoV-2 infection. PLoS Comput Biol 2020; 16:e1008461. [PMID: 33290397 PMCID: PMC7748278 DOI: 10.1371/journal.pcbi.1008461] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 12/18/2020] [Accepted: 10/22/2020] [Indexed: 12/15/2022] Open
Abstract
The entry of SARS-CoV-2 into target cells requires the activation of its surface spike protein, S, by host proteases. The host serine protease TMPRSS2 and cysteine proteases Cathepsin B/L can activate S, making two independent entry pathways accessible to SARS-CoV-2. Blocking the proteases prevents SARS-CoV-2 entry in vitro. This blockade may be achieved in vivo through 'repurposing' drugs, a potential treatment option for COVID-19 that is now in clinical trials. Here, we found, surprisingly, that drugs targeting the two pathways, although independent, could display strong synergy in blocking virus entry. We predicted this synergy first using a mathematical model of SARS-CoV-2 entry and dynamics in vitro. The model considered the two pathways explicitly, let the entry efficiency through a pathway depend on the corresponding protease expression level, which varied across cells, and let inhibitors compromise the efficiency in a dose-dependent manner. The synergy predicted was novel and arose from effects of the drugs at both the single cell and the cell population levels. Validating our predictions, available in vitro data on SARS-CoV-2 and SARS-CoV entry displayed this synergy. Further, analysing the data using our model, we estimated the relative usage of the two pathways and found it to vary widely across cell lines, suggesting that targeting both pathways in vivo may be important and synergistic given the broad tissue tropism of SARS-CoV-2. Our findings provide insights into SARS-CoV-2 entry into target cells and may help improve the deployability of drug combinations targeting host proteases required for the entry.
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Affiliation(s)
- Pranesh Padmanabhan
- Clem Jones Centre for Ageing Dementia Research, Queesnsland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Rajat Desikan
- Department of Chemical Engineering, Indian Institute of Science, Bengaluru, India
| | - Narendra M. Dixit
- Department of Chemical Engineering, Indian Institute of Science, Bengaluru, India
- Centre for Biosystems Science and Engineering, Indian Institute of Science, Bengaluru, India
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8
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Augestad EH, Castelli M, Clementi N, Ströh LJ, Krey T, Burioni R, Mancini N, Bukh J, Prentoe J. Global and local envelope protein dynamics of hepatitis C virus determine broad antibody sensitivity. SCIENCE ADVANCES 2020; 6:eabb5938. [PMID: 32923643 PMCID: PMC7449684 DOI: 10.1126/sciadv.abb5938] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 07/13/2020] [Indexed: 05/03/2023]
Abstract
Broad antibody sensitivity differences of hepatitis C virus (HCV) isolates and their ability to persist in the presence of neutralizing antibodies (NAbs) remain poorly understood. Here, we show that polymorphisms within glycoprotein E2, including hypervariable region 1 (HVR1) and antigenic site 412 (AS412), broadly affect NAb sensitivity by shifting global envelope protein conformation dynamics between theoretical "closed," neutralization-resistant and "open," neutralization-sensitive states. The conformational space of AS412 was skewed toward β-hairpin-like conformations in closed states, which also depended on HVR1, assigning function to these enigmatic E2 regions. Scavenger receptor class B, type I entry dependency of HCV was associated with NAb resistance and correlated perfectly with decreased virus propensity to interact with HCV co-receptor CD81, indicating that decreased NAb sensitivity resulted in a more complex entry pathway. This link between global E1/E2 states and functionally distinct AS412 conformations has important implications for targeting AS412 in rational HCV vaccine designs.
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Affiliation(s)
- Elias H. 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, DK-2200 Copenhagen, Denmark
| | - Matteo Castelli
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, Milano, 20132, Italy
| | - Nicola Clementi
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, Milano, 20132, Italy
| | - Luisa J. Ströh
- Institute of Virology, Hannover Medical School, Carl-Neuberg-Str. 1, Hannover 30625, Germany
| | - Thomas Krey
- Institute of Virology, Hannover Medical School, Carl-Neuberg-Str. 1, Hannover 30625, Germany
- German Center for Infection Research (DZIF), partner sites Hannover-Braunschweig and Hamburg-Lübeck-Borstel-Riems, Germany
- Center of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Luebeck, Ratzeburger Allee 160, 23562 Luebeck, Germany
- Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
- Centre for Structural Systems Biology (CSSB), Notkestraße 85, 22607 Hamburg, Germany
| | - Roberto Burioni
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, Milano, 20132, Italy
| | - Nicasio Mancini
- Laboratory of Microbiology and Virology, Università “Vita-Salute” San Raffaele, Milano, 20132, Italy
| | - 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, DK-2200 Copenhagen, Denmark
| | - 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, DK-2200 Copenhagen, Denmark
- Corresponding author.
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9
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Hepatitis C Virus Entry: An Intriguingly Complex and Highly Regulated Process. Int J Mol Sci 2020; 21:ijms21062091. [PMID: 32197477 PMCID: PMC7140000 DOI: 10.3390/ijms21062091] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/15/2020] [Accepted: 03/16/2020] [Indexed: 02/07/2023] Open
Abstract
Hepatitis C virus (HCV) is a major cause of chronic hepatitis and liver disease worldwide. Its tissue and species tropism are largely defined by the viral entry process that is required for subsequent productive viral infection and establishment of chronic infection. This review provides an overview of the viral and host factors involved in HCV entry into hepatocytes, summarizes our understanding of the molecular mechanisms governing this process and highlights the therapeutic potential of host-targeting entry inhibitors.
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10
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The Beginning of Ending Hepatitis C Virus: A Summary of the 26th International Symposium on Hepatitis C Virus and Related Viruses. Viruses 2020; 12:v12030302. [PMID: 32168867 PMCID: PMC7150740 DOI: 10.3390/v12030302] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Abstract
Hepatitis C virus (HCV) infects ~71 million people worldwide, and 399,000 people die annually due to HCV-related liver cirrhosis and hepatocellular carcinoma. The use of direct-acting antivirals results in a sustained virologic response in >95% of patients with chronic HCV infection. However, several issues remain to be solved to eradicate HCV. At the 26th International Symposium on Hepatitis C Virus and Related Viruses (HCV2019) held in Seoul, South Korea, October 5–8, 2019, virologists, immunologists, and clinical scientists discussed these remaining issues and how we can achieve the elimination of HCV.
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11
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Stejskal L, Lees WD, Moss DS, Palor M, Bingham RJ, Shepherd AJ, Grove J. Flexibility and intrinsic disorder are conserved features of hepatitis C virus E2 glycoprotein. PLoS Comput Biol 2020; 16:e1007710. [PMID: 32109245 PMCID: PMC7065822 DOI: 10.1371/journal.pcbi.1007710] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 03/11/2020] [Accepted: 02/04/2020] [Indexed: 12/15/2022] Open
Abstract
The glycoproteins of hepatitis C virus, E1E2, are unlike any other viral fusion machinery yet described, and are the current focus of immunogen design in HCV vaccine development; thus, making E1E2 both scientifically and medically important. We used pre-existing, but fragmentary, structures to model a complete ectodomain of the major glycoprotein E2 from three strains of HCV. We then performed molecular dynamic simulations to explore the conformational landscape of E2, revealing a number of important features. Despite high sequence divergence, and subtle differences in the models, E2 from different strains behave similarly, possessing a stable core flanked by highly flexible regions, some of which perform essential functions such as receptor binding. Comparison with sequence data suggest that this consistent behaviour is conferred by a network of conserved residues that act as hinge and anchor points throughout E2. The variable regions (HVR-1, HVR-2 and VR-3) exhibit particularly high flexibility, and bioinformatic analysis suggests that HVR-1 is a putative intrinsically disordered protein region. Dynamic cross-correlation analyses demonstrate intramolecular communication and suggest that specific regions, such as HVR-1, can exert influence throughout E2. To support our computational approach we performed small-angle X-ray scattering with purified E2 ectodomain; this data was consistent with our MD experiments, suggesting a compact globular core with peripheral flexible regions. This work captures the dynamic behaviour of E2 and has direct relevance to the interaction of HCV with cell-surface receptors and neutralising antibodies.
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Affiliation(s)
- Lenka Stejskal
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, United Kingdom
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - William D. Lees
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - David S. Moss
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - Machaela Palor
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Richard J. Bingham
- Department of Biological Sciences, University of Huddersfield, Huddersfield, United Kingdom
| | - Adrian J. Shepherd
- Institute of Structural and Molecular Biology, Birkbeck College, London, United Kingdom
| | - Joe Grove
- Institute of Immunity and Transplantation, Division of Infection and Immunity, University College London, London, United Kingdom
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