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Karamichali E, Foka P, Papadopoulou G, Loukaki-Gkountara D, Andresaki K, Koskinas I, Georgopoulou U. Hepatitis Viruses Control Host Immune Responses by Modifying the Exosomal Biogenesis Pathway and Cargo. Int J Mol Sci 2022; 23:10862. [PMID: 36142773 DOI: 10.3390/ijms231810862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 09/13/2022] [Accepted: 09/15/2022] [Indexed: 11/17/2022] Open
Abstract
The development of smart immune evasion mechanisms is crucial for the establishment of acute and chronic viral hepatitis. Hepatitis is a major health problem worldwide arising from different causes, such as pathogens, metabolic disorders, and xenotoxins, with the five hepatitis viruses A, B, C, D, and E (HAV, HBV, HCV, HDV, and HEV) representing the majority of the cases. Most of the hepatitis viruses are considered enveloped. Recently, it was reported that the non-enveloped HAV and HEV are, in reality, quasi-enveloped viruses exploiting exosomal-like biogenesis mechanisms for budding. Regardless, all hepatitis viruses use exosomes to egress, regulate, and eventually escape from the host immune system, revealing another key function of exosomes apart from their recognised role in intercellular communication. This review will discuss how the hepatitis viruses exploit exosome biogenesis and transport capacity to establish successful infection and spread. Then, we will outline the contribution of exosomes in viral persistence and liver disease progression.
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2
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Deng L, Liang P, Cui H. Pseudotyped lentiviral vectors: Ready for translation into targeted cancer gene therapy? Genes Dis 2022. [PMID: 37492721 PMCID: PMC10363566 DOI: 10.1016/j.gendis.2022.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Gene therapy holds great promise for curing cancer by editing the deleterious genes of tumor cells, but the lack of vector systems for efficient delivery of genetic material into specific tumor sites in vivo has limited its full therapeutic potential in cancer gene therapy. Over the past two decades, increasing studies have shown that lentiviral vectors (LVs) modified with different glycoproteins from a donating virus, a process referred to as pseudotyping, have altered tropism and display cell-type specificity in transduction, leading to selective tumor cell killing. This feature of LVs together with their ability to enable high efficient gene delivery in dividing and non-dividing mammalian cells in vivo make them to be attractive tools in future cancer gene therapy. This review is intended to summarize the status quo of some typical pseudotypings of LVs and their applications in basic anti-cancer studies across many malignancies. The opportunities of translating pseudotyped LVs into clinic use in cancer therapy have also been discussed.
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Salas JH, Urbanowicz RA, Guest JD, Frumento N, Figueroa A, Clark KE, Keck Z, Cowton VM, Cole SJ, Patel AH, Fuerst TR, Drummer HE, Major M, Tarr AW, Ball JK, Law M, Pierce BG, Foung SKH, Bailey JR. An Antigenically Diverse, Representative Panel of Envelope Glycoproteins for Hepatitis C Virus Vaccine Development. Gastroenterology 2022; 162:562-574. [PMID: 34655573 PMCID: PMC8792218 DOI: 10.1053/j.gastro.2021.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 12/21/2022]
Abstract
BACKGROUND & AIMS Development of a prophylactic hepatitis C virus (HCV) vaccine will require accurate and reproducible measurement of neutralizing breadth of vaccine-induced antibodies. Currently available HCV panels may not adequately represent the genetic and antigenic diversity of circulating HCV strains, and the lack of standardization of these panels makes it difficult to compare neutralization results obtained in different studies. Here, we describe the selection and validation of a genetically and antigenically diverse reference panel of 15 HCV pseudoparticles (HCVpps) for neutralization assays. METHODS We chose 75 envelope (E1E2) clones to maximize representation of natural polymorphisms observed in circulating HCV isolates, and 65 of these clones generated functional HCVpps. Neutralization sensitivity of these HCVpps varied widely. HCVpps clustered into 15 distinct groups based on patterns of relative sensitivity to 7 broadly neutralizing monoclonal antibodies. We used these data to select a final panel of 15 antigenically representative HCVpps. RESULTS Both the 65 and 15 HCVpp panels span 4 tiers of neutralization sensitivity, and neutralizing breadth measurements for 7 broadly neutralizing monoclonal antibodies were nearly equivalent using either panel. Differences in neutralization sensitivity between HCVpps were independent of genetic distances between E1E2 clones. CONCLUSIONS Neutralizing breadth of HCV antibodies should be defined using viruses spanning multiple tiers of neutralization sensitivity rather than panels selected solely for genetic diversity. We propose that this multitier reference panel could be adopted as a standard for the measurement of neutralizing antibody potency and breadth, facilitating meaningful comparisons of neutralization results from vaccine studies in different laboratories.
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Affiliation(s)
- Jordan H Salas
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Richard A Urbanowicz
- School of Life Sciences, Faculty of Medicine and Health Sciences, The University of Nottingham, Nottingham, United Kingdom; Wolfson Centre for Global Virus Research, The University of Nottingham, Nottingham, United Kingdom; National Institute for Health Research Nottingham Biomedical Research Centre, Nottingham University Hospitals National Health Service Trust, Nottingham, United Kingdom
| | - Johnathan D Guest
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland
| | - Nicole Frumento
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Alexis Figueroa
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Kaitlyn E Clark
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Zhenyong Keck
- Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Vanessa M Cowton
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Sarah J Cole
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Arvind H Patel
- Medical Research Council-University of Glasgow Centre for Virus Research, Glasgow, United Kingdom
| | - Thomas R Fuerst
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland
| | - Heidi E Drummer
- Viral Entry and Vaccines Group, Burnet Institute, Melbourne, Victoria, Australia; Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, Victoria, Australia; Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Marian Major
- Division of Viral Products, Center for Biologics Evaluation and Research, United States Food and Drug Administration, Silver Spring, Maryland
| | - Alexander W Tarr
- School of Life Sciences, Faculty of Medicine and Health Sciences, The University of Nottingham, Nottingham, United Kingdom; Wolfson Centre for Global Virus Research, The University of Nottingham, Nottingham, United Kingdom; National Institute for Health Research Nottingham Biomedical Research Centre, Nottingham University Hospitals National Health Service Trust, Nottingham, United Kingdom
| | - Jonathan K Ball
- School of Life Sciences, Faculty of Medicine and Health Sciences, The University of Nottingham, Nottingham, United Kingdom; Wolfson Centre for Global Virus Research, The University of Nottingham, Nottingham, United Kingdom; National Institute for Health Research Nottingham Biomedical Research Centre, Nottingham University Hospitals National Health Service Trust, Nottingham, United Kingdom
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, California
| | - Brian G Pierce
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland; Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Justin R Bailey
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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5
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Aljowaie RM, Almajhdi FN, Ali HH, El-Wetidy MS, Shier MK. Inhibition of hepatitis C virus genotype 4 replication using siRNA targeted to the viral core region and the CD81 cellular receptor. Cell Stress Chaperones 2020; 25:345-355. [PMID: 32060691 PMCID: PMC7058739 DOI: 10.1007/s12192-020-01077-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 01/21/2020] [Accepted: 01/24/2020] [Indexed: 01/12/2023] Open
Abstract
Hepatitis C virus (HCV) is one of the most important causative agents of hepatitis worldwide. The current study aimed to evaluate the silencing effect of the small interference RNA (siRNA) molecules designed against the core region of HCV genotype 4 (HCV-4) and the CD81 gene, which is the cellular receptor for HCV in the human hepatocytes. RT-PCR was used to measure the changes in both the viral HCV core and the cellular CD81 genes induced by the specific siRNA molecules. Additionally, the fluctuations in either the viral or the cellular proteins of the target regions were tested by flow cytometry and immunofluorescence. The results showed the effectiveness of the used siRNA molecules against the target genes in either RNA or protein levels. The effect of 100 nM of siCD81 and 40 nM of siCore was more evident at 24 and 48 h post-transfection. The combination of the two siRNA molecules resulted in an extra inhibitory effect of the HCV core at both the RNA (85.6%) and protein (98.5%) levels. The current study suggested that targeting of the CD81 cellular receptor and/or the viral HCV core region by the small interference molecules might be a suitable choice in the suppression of HCV-4 replication. This might assist the development of new antiviral medications and provides a new alternative strategy for the targeting and treatment of HCV genotype 4.
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Affiliation(s)
- Reem M Aljowaie
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
| | - Fahad N Almajhdi
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia
| | - Hebatallh H Ali
- College of Medicine Research Center, King Saud University, Riyadh, Saudi Arabia
| | | | - Medhat K Shier
- College of Medicine Research Center, King Saud University, Riyadh, Saudi Arabia
- Department of Medical Microbiology and Immunology, College of Medicine, Menofia University, Shibin el Kom, Egypt
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6
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Liu Y, Wang W, Zou Z, Hu Z, Fan Q, Xiong J. Hepatitis C Virus Entry into Macrophages/Monocytes Mainly Depends on the Phagocytosis of Macrophages. Dig Dis Sci 2019; 64:1226-37. [PMID: 30535782 DOI: 10.1007/s10620-018-5401-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 11/27/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Hepatitis C virus (HCV) has been classified as a strictly hepatotropic pathogen for a long time, and hepatocytes are target cells for HCV infection. More and more studies showed non-liver cells supported HCV entry and replication, such as macrophages. The mechanisms of HCV entry into macrophages are still not clear. AIMS This study aims to determine the way of HCV entry into macrophages. METHODS Cell culture-derived infectious HCV particles (HCVcc) were prepared using Huh7 cells transfected with HCV RNA. CD81-knockdown cells were obtained through siRNA transfection. HCV RNA levels were determined by RT-qPCR. Flow cytometry analyses were used to determine cell surface levels of CD11b, CD68, and CD81. ELISA and western blotting were performed to quantify the protein levels of IL-1β, IL-6, and TNF-α. Phagocytic ability was determined by neutral red uptake assay. RESULTS CD81 knockdown could not inhibit HCVcc entry into macrophages. The entry of HCV into macrophages could not be blocked by pooled IgG from chronic hepatitis C patient's sera. Macrophages derived from THP-1 cells displayed stronger phagocytic capacity, which also swallowed more HCV RNA. Treatment of macrophages with endocytic inhibitor, methyl-β-cyclodextrin, decreased the internalization of HCV. HCV uptake by macrophages was related to the reorganization of F-actin cytoskeleton and PI3Ks activation. HCV infection significantly increased the expression of IL1β and IL6 in macrophages and promoted apoptosis of macrophages. CONCLUSIONS HCV entry into macrophages mainly depends on phagocytosis of macrophages.
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Abstract
Hepatitis C virus (HCV) pseudoparticles (HCVpp) are generated by cotransfection of HCV envelope (E1 and E2) genes along with a retroviral packaging/reporter construct into HEK293T cells. Enveloped particles bearing HCV E1E2 proteins on their surface are released through a retroviral budding process into the supernatant. Viral E1E2 glycoproteins facilitate a single round of receptor-mediated entry of HCVpp into hepatoma cells, which can be quantified by reporter gene expression. These HCVpp have been employed to study mechanisms of HCV entry into hepatoma cells, as well as HCV neutralization by immune sera or HCV-specific monoclonal antibodies.
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Affiliation(s)
- Justin R Bailey
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA.
| | - Richard A Urbanowicz
- School of Life Sciences, The University of Nottingham, Nottingham, UK
- NIHR Biomedical Research Unit in Gastrointestinal and Liver Diseases, Nottingham University Hospitals NHS Trust, University of Nottingham, Nottingham, UK
| | - Jonathan K Ball
- School of Life Sciences, The University of Nottingham, Nottingham, UK
| | - Mansun Law
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Steven K H Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
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8
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Abstract
Autophagy is an evolutionarily conserved cellular process in which intracellular components are eliminated via lysosomal degradation to supply nutrients for organelle biogenesis and metabolic homeostasis. Flavivirus infections underlie multiple human diseases and thus exert an immense burden on public health worldwide. Mounting evidence indicates that host autophagy is subverted to modulate the life cycles of flaviviruses, such as hepatitis C virus, dengue virus, Japanese encephalitis virus, West Nile virus and Zika virus. The diverse interplay between autophagy and flavivirus infection not only regulates viral growth in host cells but also counteracts host stress responses induced by viral infection. In this review, we summarize the current knowledge on the role of autophagy in the flavivirus life cycle. We also discuss the impacts of virus-induced autophagy on the pathogeneses of flavivirus-associated diseases and the potential use of autophagy as a therapeutic target for curing flavivirus infections and related human diseases.
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Affiliation(s)
- Po-Yuan Ke
- Department of Biochemistry & Molecular Biology and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan.
- Liver Research Center, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
- Division of Allergy, Immunology and Rheumatology, Chang Gung Memorial Hospital, Taoyuan 33305, Taiwan.
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9
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Abstract
Extraordinary genetic diversity is a hallmark of hepatitis C virus (HCV). Therefore, accurate measurement of the breadth of antibody neutralizing activity across diverse HCV isolates is key to defining correlates of immune protection against the virus, and essential to guide vaccine development. Panels of HCV pseudoparticle (HCVpp) or replication-competent cell culture viruses (HCVcc) can be used to measure neutralizing breadth of antibodies. These in vitro assays have been used to define neutralizing breadth of antibodies in serum, to characterize broadly neutralizing monoclonal antibodies, and to identify mechanisms of HCV resistance to antibody neutralization. Recently, larger and more diverse panels of both HCVpp and HCVcc have been described that better represent the diversity of circulating HCV strains, but further work is needed to expand and standardize these neutralization panels.
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Affiliation(s)
- Valerie J Kinchen
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Justin R Bailey
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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10
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Dustin LB. Innate and Adaptive Immune Responses in Chronic HCV Infection. Curr Drug Targets 2018; 18:826-843. [PMID: 26302811 DOI: 10.2174/1389450116666150825110532] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 07/25/2015] [Accepted: 07/27/2015] [Indexed: 12/14/2022]
Abstract
Hepatitis C virus (HCV) remains a public health problem of global importance, even in the era of potent directly-acting antiviral drugs. In this chapter, I discuss immune responses to acute and chronic HCV infection. The outcome of HCV infection is influenced by viral strategies that limit or delay the initiation of innate antiviral responses. This delay may enable HCV to establish widespread infection long before the host mounts effective T and B cell responses. HCV's genetic agility, resulting from its high rate of replication and its error prone replication mechanism, enables it to evade immune recognition. Adaptive immune responses fail to keep up with changing viral epitopes. Neutralizing antibody epitopes may be hidden by decoy structures, glycans, and lipoproteins. T cell responses fail due to changing epitope sequences and due to exhaustion, a phenomenon that may have evolved to limit immune-mediated pathology. Despite these difficulties, innate and adaptive immune mechanisms do impact HCV replication. Immune-mediated clearance of infection is possible, occurring in 20-50% of people who contract the disease. New developments raise hopes for effective immunological interventions to prevent or treat HCV infection.
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Affiliation(s)
- Lynn B Dustin
- University of Oxford, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Kennedy Institute of Rheumatology, Peter Medawar Building for Pathogen Research, South Parks Road, Oxford OX1 3SY, United Kingdom
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Banse P, Moeller R, Bruening J, Lasswitz L, Kahl S, Khan AG, Marcotrigiano J, Pietschmann T, Gerold G. CD81 Receptor Regions outside the Large Extracellular Loop Determine Hepatitis C Virus Entry into Hepatoma Cells. Viruses 2018; 10:E207. [PMID: 29677132 DOI: 10.3390/v10040207] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 04/14/2018] [Accepted: 04/19/2018] [Indexed: 02/07/2023] Open
Abstract
Hepatitis C virus (HCV) enters human hepatocytes using four essential entry factors, one of which is human CD81 (hCD81). The tetraspanin hCD81 contains a large extracellular loop (LEL), which interacts with the E2 glycoprotein of HCV. The role of the non-LEL regions of hCD81 (intracellular tails, four transmembrane domains, small extracellular loop and intracellular loop) is poorly understood. Here, we studied the contribution of these domains to HCV susceptibility of hepatoma cells by generating chimeras of related tetraspanins with the hCD81 LEL. Our results show that non-LEL regions in addition to the LEL determine susceptibility of cells to HCV. While closely related tetraspanins (X. tropicalis CD81 and D. rerio CD81) functionally complement hCD81 non-LEL regions, distantly related tetraspanins (C. elegans TSP9 amd D. melanogaster TSP96F) do not and tetraspanins with intermediate homology (hCD9) show an intermediate phenotype. Tetraspanin homology and susceptibility to HCV correlate positively. For some chimeras, infectivity correlates with surface expression. In contrast, the hCD9 chimera is fully surface expressed, binds HCV E2 glycoprotein but is impaired in HCV receptor function. We demonstrate that a cholesterol-coordinating glutamate residue in CD81, which hCD9 lacks, promotes HCV infection. This work highlights the hCD81 non-LEL regions as additional HCV susceptibility-determining factors.
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12
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King B, Tarr AW. How have retrovirus pseudotypes contributed to our understanding of viral entry? Future Virol 2017. [DOI: 10.2217/fvl-2017-0062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Study of virus entry into host cells is important for understanding viral tropism and pathogenesis. Studying the entry of in vitro cultured viruses is not always practicable. Study of highly pathogenic viruses, viruses that do not grow in culture, and viruses that rapidly change phenotype in vitro can all benefit from alternative models of entry. Retrovirus particles can be engineered to display the envelope proteins of heterologous enveloped viruses. This approach, broadly termed ‘pseudotyping’, is an important technique for interrogating virus entry. In this perspective we consider how retrovirus pseudotypes have addressed these challenges and improved our understanding of the entry pathways of diverse virus species, including Ebolavirus, human immunodeficiency virus and hepatitis C virus.
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Affiliation(s)
- Barnabas King
- National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust & the University of Nottingham, Nottingham, UK
- School of Life Sciences, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, UK
| | - Alexander W Tarr
- National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust & the University of Nottingham, Nottingham, UK
- School of Life Sciences, Faculty of Medicine & Health Sciences, University of Nottingham, Nottingham, UK
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13
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Laidlaw SM, Marukian S, Gilmore RH, Cashman SB, Nechyporuk-Zloy V, Rice CM, Dustin LB. Tumor Necrosis Factor Inhibits Spread of Hepatitis C Virus Among Liver Cells, Independent From Interferons. Gastroenterology 2017; 153:566-578.e5. [PMID: 28456632 PMCID: PMC5627365 DOI: 10.1053/j.gastro.2017.04.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 04/11/2017] [Accepted: 04/21/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Tumor necrosis factor (TNF) is an inflammatory cytokine expressed by human fetal liver cells (HFLCs) after infection with cell culture-derived hepatitis C virus (HCV). TNF has been reported to increase entry of HCV pseudoparticles into hepatoma cells and inhibit signaling by interferon alpha (IFNα), but have no effect on HCV-RNA replication. We investigated the effects of TNF on HCV infection of and spread among Huh-7 hepatoma cells and primary HFLCs. METHODS Human hepatoma (Huh-7 and Huh-7.5) and primary HFLCs were incubated with TNF and/or recombinant IFNA2A, IFNB, IFNL1, and IFNL2 before or during HCV infection. We used 2 fully infectious HCV chimeric viruses of genotype 2A in these studies: J6/JFH (clone 2) and Jc1(p7-nsGluc2A) (Jc1G), which encodes a secreted luciferase reporter. We measured HCV replication, entry, spread, production, and release in hepatoma cells and HFLCs. RESULTS TNF inhibited completion of the HCV infectious cycle in hepatoma cells and HFLCs in a dose-dependent and time-dependent manner. This inhibition required TNF binding to its receptor. Inhibition was independent of IFNα, IFNβ, IFNL1, IFNL2, or Janus kinase signaling via signal transducer and activator of transcription. TNF reduced production of infectious viral particles by Huh-7 and HFLC, and thereby reduced the number of infected cells and focus size. TNF had little effect on HCV replicons and increased entry of HCV pseudoparticles. When cells were incubated with TNF before infection, the subsequent antiviral effects of IFNs were increased. CONCLUSIONS In a cell culture system, we found TNF to have antiviral effects independently of, as well as in combination with, IFNs. TNF inhibits HCV infection despite increased HCV envelope glycoprotein-mediated infection of liver cells. These findings contradict those from other studies, which have reported that TNF blocks signal transduction in response to IFNs. The destructive inflammatory effects of TNF must be considered along with its antiviral effects.
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Affiliation(s)
- Stephen M. Laidlaw
- Kennedy Institute of Rheumatology, The University of Oxford, Oxford,
UK,Peter Medawar Building for Pathogen Research, The University of
Oxford, Oxford, UK
| | - Svetlana Marukian
- Laboratory of Virology and Infectious Disease, The Rockefeller
University, New York, NY, USA
| | - Rachel H. Gilmore
- Laboratory of Virology and Infectious Disease, The Rockefeller
University, New York, NY, USA
| | - Siobhán B. Cashman
- Kennedy Institute of Rheumatology, The University of Oxford, Oxford,
UK,Peter Medawar Building for Pathogen Research, The University of
Oxford, Oxford, UK
| | | | - Charles M. Rice
- Laboratory of Virology and Infectious Disease, The Rockefeller
University, New York, NY, USA
| | - Lynn B. Dustin
- Kennedy Institute of Rheumatology, The University of Oxford, Oxford,
UK,Peter Medawar Building for Pathogen Research, The University of
Oxford, Oxford, UK,Laboratory of Virology and Infectious Disease, The Rockefeller
University, New York, NY, USA,Corresponding author:
, Peter Medawar Building for
Pathogen Research, South Parks Road, Oxford, OX1 3SY, UK
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14
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Wasilewski LN, Ray SC, Bailey JR. Hepatitis C virus resistance to broadly neutralizing antibodies measured using replication-competent virus and pseudoparticles. J Gen Virol 2016; 97:2883-2893. [PMID: 27667373 DOI: 10.1099/jgv.0.000608] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A better understanding of natural variation in neutralization resistance and fitness of diverse hepatitis C virus (HCV) envelope (E1E2) variants will be critical to guide rational development of an HCV vaccine. This work has been hindered by inadequate genetic diversity in viral panels and by a lack of standardization of HCV entry assays. Neutralization assays generally use lentiviral pseudoparticles expressing HCV envelope proteins (HCVpp) or chimeric full-length viruses that are replication competent in cell culture (HCVcc). There have been few systematic comparisons of specific infectivities of E1E2-matched HCVcc and HCVpp, and to our knowledge, neutralization of E1E2-matched HCVpp and HCVcc has never been compared using a diverse panel of human broadly neutralizing monoclonal antibodies (bNAbs) targeting distinct epitopes. Here, we describe an efficient method for introduction of naturally occurring E1E2 genes into a full-length HCV genome, producing replication-competent chimeric HCVcc. We generated diverse panels of E1E2-matched HCVcc and HCVpp and measured the entry-mediating fitness of E1E2 variants using the two systems. We also compared neutralization of E1E2-matched HCVcc and HCVpp by a diverse panel of human bNAbs targeting epitopes across E1E2. We found no correlation between specific infectivities of E1E2-matched HCVcc versus HCVpp, but found a very strong positive correlation between relative neutralization resistance of these same E1E2-matched HCVcc and HCVpp variants. These results suggest that quantitative comparisons of neutralization resistance of E1E2 variants can be made with confidence using either HCVcc or HCVpp, allowing the use of either or both systems to maximize diversity of neutralization panels.
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Affiliation(s)
- Lisa N Wasilewski
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Stuart C Ray
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA.,Department of Oncology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Justin R Bailey
- Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
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15
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Urbanowicz RA, McClure CP, King B, Mason CP, Ball JK, Tarr AW. Novel functional hepatitis C virus glycoprotein isolates identified using an optimized viral pseudotype entry assay. J Gen Virol 2016; 97:2265-2279. [PMID: 27384448 PMCID: PMC5042129 DOI: 10.1099/jgv.0.000537] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Retrovirus pseudotypes are a highly tractable model used to study the entry pathways of enveloped viruses. This model has been extensively applied to the study of the hepatitis C virus (HCV) entry pathway, preclinical screening of antiviral antibodies and for assessing the phenotype of patient-derived viruses using HCV pseudoparticles (HCVpp) possessing the HCV E1 and E2 glycoproteins. However, not all patient-isolated clones produce particles that are infectious in this model. This study investigated factors that might limit phenotyping of patient-isolated HCV glycoproteins. Genetically related HCV glycoproteins from quasispecies in individual patients were discovered to behave very differently in this entry model. Empirical optimization of the ratio of packaging construct and glycoprotein-encoding plasmid was required for successful HCVpp genesis for different clones. The selection of retroviral packaging construct also influenced the function of HCV pseudoparticles. Some glycoprotein constructs tolerated a wide range of assay parameters, while others were much more sensitive to alterations. Furthermore, glycoproteins previously characterized as unable to mediate entry were found to be functional. These findings were validated using chimeric cell-cultured HCV bearing these glycoproteins. Using the same empirical approach we demonstrated that generation of infectious ebolavirus pseudoviruses (EBOVpv) was also sensitive to the amount and ratio of plasmids used, and that protocols for optimal production of these pseudoviruses are dependent on the exact virus glycoprotein construct. These findings demonstrate that it is crucial for studies utilizing pseudoviruses to conduct empirical optimization of pseudotype production for each specific glycoprotein sequence to achieve optimal titres and facilitate accurate phenotyping.
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Affiliation(s)
- Richard A. Urbanowicz
- School of Life Sciences, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
- NIHR Nottingham Digestive Diseases Biomedical Research Unit, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - C. Patrick McClure
- School of Life Sciences, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
- NIHR Nottingham Digestive Diseases Biomedical Research Unit, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Barnabas King
- School of Life Sciences, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
- NIHR Nottingham Digestive Diseases Biomedical Research Unit, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Christopher P. Mason
- School of Life Sciences, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
- NIHR Nottingham Digestive Diseases Biomedical Research Unit, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Jonathan K. Ball
- School of Life Sciences, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
- NIHR Nottingham Digestive Diseases Biomedical Research Unit, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Alexander W. Tarr
- School of Life Sciences, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
- NIHR Nottingham Digestive Diseases Biomedical Research Unit, The University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK
- Correspondence Alexander W. Tarr
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16
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Chi X, Niu Y, Cheng M, Liu X, Feng Y, Zheng F, Fan J, Li X, Jin Q, Zhong J, Li YP, Yang W. Identification of a Potent and Broad-Spectrum Hepatitis C Virus Fusion Inhibitory Peptide from the E2 Stem Domain. Sci Rep 2016; 6:25224. [PMID: 27121372 DOI: 10.1038/srep25224] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 04/13/2016] [Indexed: 12/13/2022] Open
Abstract
Hepatitis C virus (HCV) envelope proteins E1 and E2 play an essential role in virus entry. However, the fusion mechanisms of HCV remain largely unclear, hampering the development of efficient fusion inhibitors. Here, we developed two cell-based membrane fusion models that allow for screening a peptide library covering the full-length E1 and E2 amino acid sequences. A peptide from the E2 stem domain, named E27, was found to possess the ability to block E1E2-mediated cell-cell fusion and inhibit cell entry of HCV pseudoparticles and infection of cell culture-derived HCV at nanomolar concentrations. E27 demonstrated broad-spectrum inhibition of the major genotypes 1 to 6. A time-of-addition experiment revealed that E27 predominantly functions in the late steps during HCV entry, without influencing the expression and localization of HCV co-receptors. Moreover, we demonstrated that E27 interfered with hetero-dimerization of ectopically expressed E1E2 in cells, and mutational analysis suggested that E27 might target a conserved region in E1. Taken together, our findings provide a novel candidate as well as a strategy for developing potent and broad-spectrum HCV fusion inhibitors, which may complement the current direct-acting antiviral medications for chronic hepatitis C, and shed light on the mechanism of HCV membrane fusion.
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17
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Ferns RB, Tarr AW, Hue S, Urbanowicz RA, McClure CP, Gilson R, Ball JK, Nastouli E, Garson JA, Pillay D. Hepatitis C virus quasispecies and pseudotype analysis from acute infection to chronicity in HIV-1 co-infected individuals. Virology 2016; 492:213-24. [PMID: 26971243 DOI: 10.1016/j.virol.2016.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 01/14/2016] [Accepted: 02/05/2016] [Indexed: 01/01/2023]
Abstract
HIV-1 infected patients who acquire HCV infection have higher rates of chronicity and liver disease progression than patients with HCV mono-infection. Understanding early events in this pathogenic process is important. We applied single genome sequencing of the E1 to NS3 regions and viral pseudotype neutralization assays to explore the consequences of viral quasispecies evolution from pre-seroconversion to chronicity in four co-infected individuals (mean follow up 566 days). We observed that one to three founder viruses were transmitted. Relatively low viral sequence diversity, possibly related to an impaired immune response, due to HIV infection was observed in three patients. However, the fourth patient, after an early purifying selection displayed increasing E2 sequence evolution, possibly related to being on suppressive antiretroviral therapy. Viral pseudotypes generated from HCV variants showed relative resistance to neutralization by autologous plasma but not to plasma collected from later time points, confirming ongoing virus escape from antibody neutralization.
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Affiliation(s)
- R Bridget Ferns
- Division of Infection & Immunity, Faculty of Medical Sciences, University College London, United Kingdom; Clinical Microbiology & Virology, UCL Hospital NHS Foundation Trust, United Kingdom.
| | - Alexander W Tarr
- School of Life Sciences & NIHR Biomedical Research Unit in Gastrointestinal & Liver Diseases, Faculty of Medicine and Health Sciences, University of Nottingham, United Kingdom
| | - Stephane Hue
- Division of Infection & Immunity, Faculty of Medical Sciences, University College London, United Kingdom
| | - Richard A Urbanowicz
- School of Life Sciences & NIHR Biomedical Research Unit in Gastrointestinal & Liver Diseases, Faculty of Medicine and Health Sciences, University of Nottingham, United Kingdom
| | - C Patrick McClure
- School of Life Sciences & NIHR Biomedical Research Unit in Gastrointestinal & Liver Diseases, Faculty of Medicine and Health Sciences, University of Nottingham, United Kingdom
| | - Richard Gilson
- Research Department of Infection and Population Health, University College London, United Kingdom
| | - Jonathan K Ball
- School of Life Sciences & NIHR Biomedical Research Unit in Gastrointestinal & Liver Diseases, Faculty of Medicine and Health Sciences, University of Nottingham, United Kingdom
| | - Eleni Nastouli
- Clinical Microbiology & Virology, UCL Hospital NHS Foundation Trust, United Kingdom
| | - Jeremy A Garson
- Division of Infection & Immunity, Faculty of Medical Sciences, University College London, United Kingdom
| | - Deenan Pillay
- Division of Infection & Immunity, Faculty of Medical Sciences, University College London, United Kingdom; Wellcome Trust Africa Centre for Health and Population Sciences, University of KwaZulu, Natal, South Africa
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18
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King B, Temperton NJ, Grehan K, Scott SD, Wright E, Tarr AW, Daly JM. Technical considerations for the generation of novel pseudotyped viruses. Future Virol 2016. [DOI: 10.2217/fvl.15.106] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A pseudotyped virus (PV) is a virus particle with an envelope protein originating from a different virus. The ability to dictate which envelope proteins are expressed on the surface has made pseudotyping an important tool for basic virological studies such as determining the cellular targets of the envelope protein of the virus as well as identification of potential antiviral compounds and measuring specific antibody responses. In this review, we describe the common methodologies employed to generate PVs, with a focus on approaches to improve the efficacy of PV generation.
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Affiliation(s)
- Barnabas King
- School of Life Sciences & NIHR Biomedical Research Unit in Gastrointestinal & Liver Diseases, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
- NIHR Biomedical Research Unit in Gastrointestinal & Liver Diseases, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Nigel J Temperton
- Viral Pseudotype Unit (Medway), School of Pharmacy, Anson Building, Central Avenue, Chatham Maritime, Chatham, Kent, ME4 4TB, UK
| | - Keith Grehan
- Viral Pseudotype Unit (Medway), School of Pharmacy, Anson Building, Central Avenue, Chatham Maritime, Chatham, Kent, ME4 4TB, UK
| | - Simon D Scott
- Viral Pseudotype Unit (Medway), School of Pharmacy, Anson Building, Central Avenue, Chatham Maritime, Chatham, Kent, ME4 4TB, UK
| | - Edward Wright
- Viral Pseudotype Unit (Fitzrovia), Faculty of Science & Technology, University of Westminster, 115 New Cavendish Street, London, W1W 6UW, UK
| | - Alexander W Tarr
- School of Life Sciences & NIHR Biomedical Research Unit in Gastrointestinal & Liver Diseases, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
- NIHR Biomedical Research Unit in Gastrointestinal & Liver Diseases, Queen's Medical Centre, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Janet M Daly
- School of Veterinary Medicine & Science, University of Nottingham, Sutton Bonington Campus, Leicestershire, LE12 5RD, UK
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19
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Sun J, Brusic V. A systematic analysis of a broadly neutralizing antibody AR3C epitopes on Hepatitis C virus E2 envelope glycoprotein and their cross-reactivity. BMC Med Genomics 2015; 8 Suppl 4:S6. [PMID: 26681161 PMCID: PMC4682370 DOI: 10.1186/1755-8794-8-s4-s6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Background Hepatitis C virus (HCV) belongs to Flaviviridae family of viruses. HCV represents a major challenge to public health since its estimated global prevalence is 2.8% of the world's human population. The design and development of HCV vaccine has been hampered by rapid evolution of viral quasispecies resulting in antibody escape variants. HCV envelope glycoprotein E1 and E2 that mediate fusion and entry of the virus into host cells are primary targets of the host immune responses. Results Structural characterization of E2 core protein and a broadly neutralizing antibody AR3C together with E1E2 sequence information enabled the analysis of B-cell epitope variability. The E2 binding site by AR3C and its surrounding area were identified from the crystal structure of E2c-AR3C complex. We clustered HCV strains using the concept of "discontinuous motif/peptide" and classified B-cell epitopes based on their similarity. Conclusions The assessment of antibody neutralizing coverage provides insights into potential cross-reactivity of the AR3C neutralizing antibody across a large number of HCV variants.
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20
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Abstract
Despite advances in therapy, hepatitis C virus infection remains a major global health issue with 3 to 4 million incident cases and 170 million prevalent chronic infections. Complex, partially understood, host-virus interactions determine whether an acute infection with hepatitis C resolves, as occurs in approximately 30% of cases, or generates a persistent hepatic infection, as occurs in the remainder. Once chronic infection is established, the velocity of hepatocyte injury and resultant fibrosis is significantly modulated by immunologic as well as environmental factors. Immunomodulation has been the backbone of antiviral therapy despite poor understanding of its mechanism of action.
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Affiliation(s)
- David E. Kaplan
- Medicine and Research Services, Philadelphia VA Medical Center, Philadelphia PA,Division of Gastroenterology, Department of Medicine, University of Pennsylvania
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21
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Kong L, Kadam RU, Giang E, Ruwona TB, Nieusma T, Culhane JC, Stanfield RL, Dawson PE, Wilson IA, Law M. Structure of Hepatitis C Virus Envelope Glycoprotein E1 Antigenic Site 314-324 in Complex with Antibody IGH526. J Mol Biol 2015; 427:2617-28. [PMID: 26135247 PMCID: PMC4523428 DOI: 10.1016/j.jmb.2015.06.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 06/17/2015] [Accepted: 06/18/2015] [Indexed: 01/19/2023]
Abstract
Hepatitis C virus (HCV) is a positive-strand RNA virus within the Flaviviridae family. The viral "spike" of HCV is formed by two envelope glycoproteins, E1 and E2, which together mediate viral entry by engaging host receptors and undergoing conformational changes to facilitate membrane fusion. While E2 can be readily produced in the absence of E1, E1 cannot be expressed without E2 and few reagents, including monoclonal antibodies (mAbs), are available for study of this essential HCV glycoprotein. A human mAb to E1, IGH526, was previously reported to cross-neutralize different HCV isolates, and therefore, we sought to further characterize the IGH526 neutralizing epitope to obtain information for vaccine design. We found that mAb IGH526 bound to a discontinuous epitope, but with a major component corresponding to E1 residues 314-324. The crystal structure of IGH526 Fab with this E1 glycopeptide at 1.75Å resolution revealed that the antibody binds to one face of an α-helical peptide. Single mutations on the helix substantially lowered IGH526 binding but did not affect neutralization, indicating either that multiple mutations are required or that additional regions are recognized by the antibody in the context of the membrane-associated envelope oligomer. Molecular dynamics simulations indicate that the free peptide is flexible in solution, suggesting that it requires stabilization for use as a candidate vaccine immunogen.
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Affiliation(s)
- Leopold Kong
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Rameshwar U Kadam
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Erick Giang
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Tinashe B Ruwona
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Travis Nieusma
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Jeffrey C Culhane
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Robyn L Stanfield
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Philip E Dawson
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Cell and Molecular Biology, 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; The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.
| | - Mansun Law
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037, USA.
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22
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23
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Neveu G, Ziv-Av A, Barouch-Bentov R, Berkerman E, Mulholland J, Einav S. AP-2-associated protein kinase 1 and cyclin G-associated kinase regulate hepatitis C virus entry and are potential drug targets. J Virol 2015; 89:4387-404. [PMID: 25653444 DOI: 10.1128/JVI.02705-14] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED Hepatitis C virus (HCV) enters its target cell via clathrin-mediated endocytosis. AP-2-associated protein kinase 1 (AAK1) and cyclin G-associated kinase (GAK) are host kinases that regulate clathrin adaptor protein (AP)-mediated trafficking in the endocytic and secretory pathways. We previously reported that AAK1 and GAK regulate HCV assembly by stimulating binding of the μ subunit of AP-2, AP2M1, to HCV core protein. We also discovered that AAK1 and GAK inhibitors, including the approved anticancer drugs sunitinib and erlotinib, could block HCV assembly. Here, we hypothesized that AAK1 and GAK regulate HCV entry independently of their effect on HCV assembly. Indeed, silencing AAK1 and GAK expression inhibited entry of pseudoparticles and cell culture grown-HCV and internalization of Dil-labeled HCV particles with no effect on HCV attachment or RNA replication. AAK1 or GAK depletion impaired epidermal growth factor (EGF)-mediated enhanced HCV entry and endocytosis of EGF receptor (EGFR), an HCV entry cofactor and erlotinib's cancer target. Moreover, either RNA interference-mediated depletion of AP2M1 or NUMB, each a substrate of AAK1 and/or GAK, or overexpression of either an AP2M1 or NUMB phosphorylation site mutant inhibited HCV entry. Last, in addition to affecting assembly, sunitinib and erlotinib inhibited HCV entry at a postbinding step, their combination was synergistic, and their antiviral effect was reversed by either AAK1 or GAK overexpression. Together, these results validate AAK1 and GAK as critical regulators of HCV entry that function in part by activating EGFR, AP2M1, and NUMB and as the molecular targets underlying the antiviral effect of sunitinib and erlotinib (in addition to EGFR), respectively. IMPORTANCE Understanding the host pathways hijacked by HCV is critical for developing host-centered anti-HCV approaches. Entry represents a potential target for antiviral strategies; however, no FDA-approved HCV entry inhibitors are currently available. We reported that two host kinases, AAK1 and GAK, regulate HCV assembly. Here, we provide evidence that AAK1 and GAK regulate HCV entry independently of their role in HCV assembly and define the mechanisms underlying AAK1- and GAK-mediated HCV entry. By regulating temporally distinct steps in the HCV life cycle, AAK1 and GAK represent "master regulators" of HCV infection and potential targets for antiviral strategies. Indeed, approved anticancer drugs that potently inhibit AAK1 or GAK inhibit HCV entry in addition to assembly. These results contribute to an understanding of the mechanisms of HCV entry and reveal attractive host targets for antiviral strategies as well as approved candidate inhibitors of these targets, with potential implications for other viruses that hijack clathrin-mediated pathways.
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Matsuda M, Suzuki R, Kataoka C, Watashi K, Aizaki H, Kato N, Matsuura Y, Suzuki T, Wakita T. Alternative endocytosis pathway for productive entry of hepatitis C virus. J Gen Virol 2014; 95:2658-2667. [PMID: 25096815 DOI: 10.1099/vir.0.068528-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Previous studies have shown that hepatitis C virus (HCV) enters human hepatic cells through interaction with a series of cellular receptors, followed by clathrin-mediated, pH-dependent endocytosis. Here, we investigated the mechanisms of HCV entry into multiple HCV-permissive human hepatocyte-derived cells using trans-complemented HCV particles (HCVtcp). Knockdown of CD81 and claudin-1, or treatment with bafilomycin A1, reduced infection in Huh-7 and Huh7.5.1 cells, suggesting that HCV entered both cell types via receptor-mediated, pH-dependent endocytosis. Interestingly, knockdown of the clathrin heavy chain or dynamin-2 (Dyn2), as well as expression of the dominant-negative form of Dyn2, reduced infection of Huh-7 cells with HCVtcp, whereas infectious entry of HCVtcp into Huh7.5.1 cells was not impaired. Infection of Huh7.5.1 cells with culture-derived HCV (HCVcc) via a clathrin-independent pathway was also observed. Knockdown of caveolin-1, ADP-ribosylation factor 6 (Arf6), flotillin, p21-activated kinase 1 (PAK1) and the PAK1 effector C-terminal binding protein 1 of E1A had no inhibitory effects on HCVtcp infection into Huh7.5.1 cells, thus suggesting that the infectious entry pathway of HCV into Huh7.5.1 cells was not caveolae-mediated, or Arf6- and flotillin-mediated endocytosis and macropinocytosis, but rather may have occurred via an undefined endocytic pathway. Further analysis revealed that HCV entry was clathrin- and dynamin-dependent in ORL8c and HepCD81/miR122 cells, but productive entry of HCV was clathrin- and dynamin-independent in Hep3B/miR122 cells. Collectively, these data indicated that HCV entered different target cells through different entry routes.
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Affiliation(s)
- Mami Matsuda
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ryosuke Suzuki
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Chikako Kataoka
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Koichi Watashi
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hideki Aizaki
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Nobuyuki Kato
- Department of Tumor Virology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama, Japan
| | - Yoshiharu Matsuura
- Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Tetsuro Suzuki
- Department of Infectious Diseases, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Takaji Wakita
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
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25
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Nakai M, Seya T, Matsumoto M, Shimotohno K, Sakamoto N, Aly HH. The J6JFH1 Strain of Hepatitis C Virus Infects Human B-Cells with Low Replication Efficacy. Viral Immunol 2014; 27:285-94. [DOI: 10.1089/vim.2013.0140] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Masato Nakai
- Department of Microbiology and Immunology, Hokkaido University Graduate School of Medicine, Kita-ku, Japan
- Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Kita-ku, Japan
| | - Tsukasa Seya
- Department of Microbiology and Immunology, Hokkaido University Graduate School of Medicine, Kita-ku, Japan
| | - Misako Matsumoto
- Department of Microbiology and Immunology, Hokkaido University Graduate School of Medicine, Kita-ku, Japan
| | - Kunitada Shimotohno
- Research Center for Hepatitis and Immunology, National Center for Global Health and Medicine, Ichikawa, Japan
| | - Naoya Sakamoto
- Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Kita-ku, Japan
| | - Hussein H. Aly
- Department of Microbiology and Immunology, Hokkaido University Graduate School of Medicine, Kita-ku, Japan
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26
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Abstract
Despite the development of potent antiviral drugs, HCV remains a global health problem; global eradication is a long way off. In this review, we discuss the immune response to HCV infection and particularly, the interplay between viral strategies that delay the onset of antiviral responses and host strategies that limit or even eradicate infected cells but also contribute to pathogenesis. Although HCV can disable some cellular virus-sensing machinery, IFN-stimulated antiviral genes are induced in the infected liver. Whereas epitope evolution contributes to escape from T cell-mediated immunity, chronic high antigen load may also blunt the T cell response by activating exhaustion or tolerance mechanisms. The evasive maneuvers of HCV limit sterilizing humoral immunity through rapid evolution of decoy epitopes, epitope masking, stimulation of interfering antibodies, lipid shielding, and cell-to-cell spread. Whereas the majority of HCV infections progress to chronic hepatitis with persistent viremia, at least 20% of patients spontaneously clear the infection. Most of these are protected from reinfection, suggesting that protective immunity to HCV exists and that a prophylactic vaccine may be an achievable goal. It is therefore important that we understand the correlates of protective immunity and mechanisms of viral persistence.
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Affiliation(s)
- Lynn B Dustin
- University of Oxford, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Kennedy Institute of Rheumatology, Oxford, United Kingdom
| | - Siobhán B Cashman
- University of Oxford, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Kennedy Institute of Rheumatology, Oxford, United Kingdom
| | - Stephen M Laidlaw
- University of Oxford, Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences, Kennedy Institute of Rheumatology, Oxford, United Kingdom
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27
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Sabahi A, Uprichard SL, Wimley WC, Dash S, Garry RF. Unexpected structural features of the hepatitis C virus envelope protein 2 ectodomain. J Virol 2014; 88:10280-8. [PMID: 24991010 DOI: 10.1128/JVI.00874-14] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Hepatitis C virus (HCV), a member of the family Flaviviridae, is a leading cause of chronic liver disease and cancer. Recent advances in HCV therapeutics have resulted in improved cure rates, but an HCV vaccine is not available and is urgently needed to control the global pandemic. Vaccine development has been hampered by the lack of high-resolution structural information for the two HCV envelope glycoproteins, E1 and E2. Recently, Kong and coworkers (Science 342:1090-1094, 2013, doi:10.1126/science.1243876) and Khan and coworkers (Nature 509[7500]:381-384, 2014, doi:10.1038/nature13117) independently determined the structure of the HCV E2 ectodomain core with some unexpected and informative results. The HCV E2 ectodomain core features a globular architecture with antiparallel β-sheets forming a central β sandwich. The residues comprising the epitopes of several neutralizing and nonneutralizing human monoclonal antibodies were also determined, which is an essential step toward obtaining a fine map of the human humoral response to HCV. Also clarified were the regions of E2 that directly bind CD81, an important HCV cellular receptor. While it has been widely assumed that HCV E2 is a class II viral fusion protein (VFP), the newly determined structure suggests that the HCV E2 ectodomain shares structural and functional similarities only with domain III of class II VFPs. The new structural determinations suggest that the HCV glycoproteins use a different mechanism than that used by class II fusion proteins for cell fusion.
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Holder KA, Russell RS, Grant MD. Natural killer cell function and dysfunction in hepatitis C virus infection. Biomed Res Int 2014; 2014:903764. [PMID: 25057504 DOI: 10.1155/2014/903764] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 04/14/2014] [Indexed: 01/06/2023]
Abstract
Viruses must continually adapt against dynamic innate and adaptive responses of the host immune system to establish chronic infection. Only a small minority (~20%) of those exposed to hepatitis C virus (HCV) spontaneously clear infection, leaving approximately 200 million people worldwide chronically infected with HCV. A number of recent research studies suggest that establishment and maintenance of chronic HCV infection involve natural killer (NK) cell dysfunction. This relationship is illustrated in vitro by disruption of typical NK cell responses including both cell-mediated cytotoxicity and cytokine production. Expression of a number of activating NK cell receptors in vivo is also affected in chronic HCV infection. Thus, direct in vivo and in vitro evidence of compromised NK function in chronic HCV infection in conjunction with significant epidemiological associations between the outcome of HCV infection and certain combinations of NK cell regulatory receptor and class I human histocompatibility linked antigen (HLA) genotypes indicate that NK cells are important in the immune response against HCV infection. In this review, we highlight evidence suggesting that selective impairment of NK cell activity is related to establishment of chronic HCV infection.
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Mathiesen CK, Jensen TB, Prentoe J, Krarup H, Nicosia A, Law M, Bukh J, Gottwein JM. Production and characterization of high-titer serum-free cell culture grown hepatitis C virus particles of genotype 1-6. Virology 2014; 458-459:190-208. [PMID: 24928051 DOI: 10.1016/j.virol.2014.03.021] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 03/16/2014] [Accepted: 03/20/2014] [Indexed: 12/18/2022]
Abstract
Recently, cell culture systems producing hepatitis C virus particles (HCVcc) were developed. Establishment of serum-free culture conditions is expected to facilitate development of a whole-virus inactivated HCV vaccine. We describe generation of genotype 1-6 serum-free HCVcc (sf-HCVcc) from Huh7.5 hepatoma cells cultured in adenovirus expression medium. Compared to HCVcc, sf-HCVcc showed 0.6-2.1 log10 higher infectivity titers (4.7-6.2 log10 Focus Forming Units/mL), possibly due to increased release and specific infectivity of sf-HCVcc. In contrast to HCVcc, sf-HCVcc had a homogeneous single-peak density profile. Entry of sf-HCVcc depended on HCV co-receptors CD81, LDLr, and SR-BI, and clathrin-mediated endocytosis. HCVcc and sf-HCVcc were neutralized similarly by chronic-phase patient sera and by human monoclonal antibodies targeting conformational epitopes. Thus, we developed serum-free culture systems producing high-titer single-density sf-HCVcc, showing similar biological properties as HCVcc. This methodology has the potential to advance HCV vaccine development and to facilitate biophysical studies of HCV.
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Affiliation(s)
- Christian K Mathiesen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital, Kettegaard Allé 30, 2650 Hvidovre, Denmark; Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Tanja B Jensen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital, Kettegaard Allé 30, 2650 Hvidovre, Denmark; Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Jannick Prentoe
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital, Kettegaard Allé 30, 2650 Hvidovre, Denmark; Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Henrik Krarup
- Department of Clinical Biochemistry, Section of Molecular Diagnostics, Aalborg University Hospital, Fredrik Bajers Vej 5, 9220 Aalborg, Denmark
| | - Alfredo Nicosia
- CEINGE, Via Gaetano Salvatore, 486, 80145 Naples, Italy; Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, via S. Pansini 5, 80131, Naples, Italy; Okairos, viale Citta' d' Europa 279, 00144, Rome, Italy
| | - Mansun Law
- Department of Immunology and Microbial Science, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital, Kettegaard Allé 30, 2650 Hvidovre, Denmark; Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Judith M Gottwein
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital, Kettegaard Allé 30, 2650 Hvidovre, Denmark; Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
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Ke PY, Chen SSL. Autophagy in hepatitis C virus-host interactions: potential roles and therapeutic targets for liver-associated diseases. World J Gastroenterol 2014; 20:5773-93. [PMID: 24914338 PMCID: PMC4024787 DOI: 10.3748/wjg.v20.i19.5773] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 01/14/2014] [Accepted: 03/04/2014] [Indexed: 02/06/2023] Open
Abstract
Autophagy is a lysosome-associated, degradative process that catabolizes cytosolic components to recycle nutrients for further use and maintain cell homeostasis. Hepatitis C virus (HCV) is a major cause of chronic hepatitis, which often leads to end-stage liver-associated diseases and is a significant burden on worldwide public health. Emerging lines of evidence indicate that autophagy plays an important role in promoting the HCV life cycle in host cells. Moreover, the diverse impacts of autophagy on a variety of signaling pathways in HCV-infected cells suggest that the autophagic process is required for balancing HCV-host cell interactions and involved in the pathogenesis of HCV-related liver diseases. However, the detailed molecular mechanism underlying how HCV activates autophagy to benefit viral growth is still enigmatic. Additionally, how the autophagic response contributes to disease progression in HCV-infected cells remains largely unknown. Hence, in this review, we overview the interplay between autophagy and the HCV life cycle and propose possible mechanisms by which autophagy may promote the pathogenesis of HCV-associated chronic liver diseases. Moreover, we outline the related studies on how autophagy interplays with HCV replication and discuss the possible implications of autophagy and viral replication in the progression of HCV-induced liver diseases, e.g., steatosis and hepatocellular carcinoma. Finally, we explore the potential therapeutics that target autophagy to cure HCV infection and its related liver diseases.
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Zona L, Tawar RG, Zeisel MB, Xiao F, Schuster C, Lupberger J, Baumert TF. CD81-receptor associations--impact for hepatitis C virus entry and antiviral therapies. Viruses 2014; 6:875-92. [PMID: 24553110 DOI: 10.3390/v6020875] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 02/12/2014] [Accepted: 02/13/2014] [Indexed: 02/07/2023] Open
Abstract
Tetraspanins are integral transmembrane proteins organized in microdomains displaying specific and direct interactions with other tetraspanins and molecular partners. Among them, CD81 has been implicated in a variety of physiological and pathological processes. CD81 also plays a crucial role in pathogen entry into host cells, including hepatitis C virus (HCV) entry into hepatocytes. HCV is a major cause of liver cirrhosis and hepatocellular carcinoma. HCV entry into hepatocytes is a complex process that requires the coordinated interaction of viral and host factors for the initiation of infection, including CD81, scavenger receptor BI, claudin-1, occludin, membrane-bound host cell kinases, Niemann-Pick C1 Like 1, Harvey rat sarcoma viral oncogene homolog (HRas), CD63 and transferrin receptor 1. Furthermore, recent data in HCV model systems have demonstrated that targeting critical components of tetraspanins and associated cell membrane proteins open new avenues to prevent and treat viral infection.
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Abstract
Hepatitis C Virus (HCV) infection is a global public health problem affecting over 160 million individuals worldwide. Its symptoms include chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. HCV is an enveloped RNA virus mainly targeting liver cells and for which the initiation of infection occurs through a complex multistep process involving a series of specific cellular entry factors. This process is likely mediated through the formation of a tightly orchestrated complex of HCV entry factors at the plasma membrane. Among HCV entry factors, the tetraspanin CD81 is one of the best characterized and it is undoubtedly a key player in the HCV lifecycle. In this review, we detail the current knowledge on the involvement of CD81 in the HCV lifecycle, as well as in the immune response to HCV infection.
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Affiliation(s)
- Lucie Fénéant
- Center for Infection and Immunity of Lille, CNRS-UMR8204, Inserm-U1019, Institut Pasteur de Lille, Université Lille Nord de France, Institut de Biologie de Lille, 1 rue du Pr Calmette, CS50447, 59021 Lille Cedex, France.
| | - Shoshana Levy
- Department of Medicine, Division of Oncology, CCSR, Stanford University Medical Center, Stanford, CA 94305, USA.
| | - Laurence Cocquerel
- Center for Infection and Immunity of Lille, CNRS-UMR8204, Inserm-U1019, Institut Pasteur de Lille, Université Lille Nord de France, Institut de Biologie de Lille, 1 rue du Pr Calmette, CS50447, 59021 Lille Cedex, France.
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Abstract
ABSTRACT: The elucidation of the mechanisms by which HCV infects hepatocytes and replicates has been paramount for identifying therapeutic targets and developing the highly efficacious antiviral drugs from which we benefit today. The earliest stage of HCV infection is viral entry, a process in which a complex interplay is thought to occur between host molecules (including glycosaminoglycans, low-density lipoprotein receptor, CD81, SR-B1, CLDN1, OCLN, EGF receptor, ephrin type A receptor 2 and transferrin receptor 1) and envelope viral glycoproteins E1 and E2. The wealth of experimental data produced in the field of HCV entry is summarized in a proposed mechanism, updated to include the most recently published data on the topic. Compounds with putative entry-blocking and/or entry-inhibiting activity in vitro and in vivo are also briefly reviewed.
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Affiliation(s)
- Andrea Magri
- Department of Translational Medicine, Università degli Studi del Piemonte Orientale “A. Avogadro”, Via Solaroli 17, 28100 Novara, Italy
| | - Simone Bocchetta
- Department of Translational Medicine, Università degli Studi del Piemonte Orientale “A. Avogadro”, Via Solaroli 17, 28100 Novara, Italy
| | - Michela Emma Burlone
- Department of Translational Medicine, Università degli Studi del Piemonte Orientale “A. Avogadro”, Via Solaroli 17, 28100 Novara, Italy
| | - Rosalba Minisini
- Department of Translational Medicine, Università degli Studi del Piemonte Orientale “A. Avogadro”, Via Solaroli 17, 28100 Novara, Italy
| | - Mario Pirisi
- Department of Translational Medicine, Università degli Studi del Piemonte Orientale “A. Avogadro”, Via Solaroli 17, 28100 Novara, Italy
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Féray C, Bouscaillou J, Falissard B, Mohamed MK, Arafa N, Bakr I, El-Hoseiny M, Daly ME, El-Kafrawy S, Plancoulaine S, Abdel-Hamid M, Thiers V, Fontanet A. A novel method to identify routes of hepatitis C virus transmission. PLoS One 2014; 9:e86098. [PMID: 24465895 PMCID: PMC3900465 DOI: 10.1371/journal.pone.0086098] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Accepted: 12/04/2013] [Indexed: 01/18/2023] Open
Abstract
Background We propose a new approach based on genetic distances among viral strains to infer about risk exposures and location of transmission at population level. Methods We re-analysed 133 viral sequences obtained during a cross-sectional survey of 4020 subjects living in a hepatitis C virus (HCV) endemic area in 2002. A permutation test was used to analyze the correlation between matrices of genetic distances in the NS5b region of all pairwise combinations of the 133 viral strains and exposure status (jointly exposed or not) to several potential HCV risk factors. Results Compared to subjects who did not share the same characteristics or iatrogenic exposures, the median Kimura genetic distances of viral strains were significantly smaller between brothers and sisters (0.031 versus 0.102, P<0.001), mother and child (0.044 versus 0.102, P<0.001), father and child (0.045 versus 0.102, P<0.001), or subjects exposed to periodontal treatment (0.084 versus 0.102, P = 0.02). Conversely, viral strains were more divergent between subjects exposed to blood transfusions (0.216 versus 0.102, P = 0.04) or tooth filling or extraction (0.108, versus 0.097, P = 0.05), suggesting acquisition of the virus outside of the village. Conclusion This method provided insights on where infection took place (household, village) for several socio-demographic characteristics or iatrogenic procedures, information of great relevance for targeting prevention interventions. This method may have interesting applications for virologists and epidemiologists studying transmission networks in health-care facilities or among intravenous drug users.
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Affiliation(s)
- Cyrille Féray
- Inserm 955, Hopital Henri Mondor, Créteil, France
- * E-mail:
| | - Julie Bouscaillou
- Institut Pasteur, Unité d’Epidémiologie des Maladies Emergentes, Paris, France
| | | | - Mostafa K. Mohamed
- Department of Community, Environmental and Occupational Medicine, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Naglaa Arafa
- Department of Community, Environmental and Occupational Medicine, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Iman Bakr
- Department of Community, Environmental and Occupational Medicine, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Mostafa El-Hoseiny
- Department of Community, Environmental and Occupational Medicine, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Mai El Daly
- National Liver Institute, Menoufia University, Shebeen El-Kom, Menufia, Egypt
- Viral Hepatitis Research Laboratory, National Hepatology and Tropical Medicine Research Institute, Cairo, Egypt
| | - Sherif El-Kafrawy
- National Liver Institute, Menoufia University, Shebeen El-Kom, Menufia, Egypt
- Viral Hepatitis Research Laboratory, National Hepatology and Tropical Medicine Research Institute, Cairo, Egypt
| | | | - Mohamed Abdel-Hamid
- Viral Hepatitis Research Laboratory, National Hepatology and Tropical Medicine Research Institute, Cairo, Egypt
- Department of Microbiology, Faculty of Medicine, Minia University, Minya, Egypt
| | - Valérie Thiers
- Unité INSERM 785, Centre Hépato-Biliaire, Villejuif, France
| | - Arnaud Fontanet
- Institut Pasteur, Unité d’Epidémiologie des Maladies Emergentes, Paris, France
- Conservatoire National des Arts et Métiers, Chaire Santé et Développement, Paris, France
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Tabll AA, Atef K, Bader El Din NG, El Abd YS, Salem A, Sayed AA, Dawood RM, Omran MH, El-Awady MK. In vitro neutralization of HCV by goat antibodies against peptides encompassing regions downstream of HVR-1 of E2 glycoprotein. J Immunoassay Immunochem 2014; 35:12-25. [PMID: 24063613 DOI: 10.1080/15321819.2013.779925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This article aims at testing several in vitro systems with various viral sources and cell lines for propagation of HCV to evaluate goat antibodies raised against three E2 epitopes in viral neutralization experiments. Four human cell lines (Huh-7, Huh-7.5, HepG2, and CaCo2) were tested using two different HCV viral sources; Genotype 4 infected sera and J6/JFH HCV cc particles. Neutralization capacity of goat Abs against conserved E2 epitopes; p412 (a.a 412-419), p517 (a.a 517-531), and p430 (a.a 430-447) were examined in the above mentioned in vitro systems. Although infection with patients' sera seems to mimic the in vitro situation, it has limited replication rates as compared with HCV cc particularly in Huh7.5 cells. Non-HCV adapted Huh-7 cells were also found susceptible for transfection with J6/JFH virus but at much slower kinetics. The results of the neutralization assay showed that anti p412 and anti p517 were highly neutralizing to HCVcc. Our data demonstrate that antibodies directed against the viral surface glycoprotein E2 reduced the infectivity of the J6/JFH virus and are promising agents for immunotherapy and HCV vaccine development.
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Affiliation(s)
- Ashraf A Tabll
- a Department of Microbial Biotechnology National Research Center , Gizza , Egypt
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Che P, Tang H, Li Q. The interaction between claudin-1 and dengue viral prM/M protein for its entry. Virology 2013; 446:303-13. [PMID: 24074594 DOI: 10.1016/j.virol.2013.08.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 07/18/2013] [Accepted: 08/09/2013] [Indexed: 02/04/2023]
Abstract
Dengue disease is becoming a huge public health concern around the world as more than one-third of the world's population living in areas at risk of infection. In an effort to assess host factors interacting with dengue virus, we identified claudin-1, a major tight junction component, as an essential cell surface protein for dengue virus entry. When claudin-1 was knocked down in Huh 7.5 cells via shRNA, the amount of dengue virus entering host cells was reduced. Consequently, the progeny virus productions were decreased and dengue virus-induced CPE was prevented. Furthermore, restoring the expression of claudin-1 in the knockdown cells facilitated dengue virus entry. The interaction between claudin-1 and dengue viral prM protein was further demonstrated using the pull-down assay. Deletion of the extracellular loop 1 (ECL1) of claudin-1 abolished such interaction, so did point mutations C54A, C64A and I32M on ECL1. These results suggest that the interaction between viral protein prM and host protein claudin-1 was essential for dengue entry. Since host and viral factors involved in virus entry are promising therapeutic targets, determining the essential role of claudin-1 could lead to the discovery of entry inhibitors with attractive therapeutic potential against dengue disease.
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Affiliation(s)
- Pulin Che
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States; University of Alabama at Birmingham, Department of Medicine, Division of Infectious Diseases, BBRB 562, 845 19th Street South, Birmingham, AL 35294, United States
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Macarthur KL, Smolic R, Smolic MV, Wu CH, Wu GY. Update on the Development of Anti-Viral Agents Against Hepatitis C. J Clin Transl Hepatol 2013; 1:9-21. [PMID: 26357602 PMCID: PMC4521270 DOI: 10.14218/jcth.2013.007xx] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/14/2013] [Accepted: 05/14/2013] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) infects nearly 170 million people worldwide and causes chronic hepatitis, cirrhosis, and hepatocellular carcinoma. The search for a drug regimen that maximizes efficacy and minimizes side effects is quickly evolving. This review will discuss a wide range of drug targets currently in all phases of development for the treatment of HCV. Direct data from agents in phase III/IV clinical trials will be presented, along with reported side-effect profiles. The mechanism of action of all treatments and resistance issues are highlighted. Special attention is given to available trial data supporting interferon-free treatment regimens. HCV has become an increasingly important public health concern, and it is important for physicians to stay up to date on the rapidly growing novel therapeutic options.
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Affiliation(s)
| | | | | | - Catherine H. Wu
- Department of Medicine, Division of Gastroenterology-Hepatology, University of Connecticut Health Center, Farmington, CT, USA
| | - George Y. Wu
- Department of Medicine, Division of Gastroenterology-Hepatology, University of Connecticut Health Center, Farmington, CT, USA
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Holder KA, Stapleton SN, Gallant ME, Russell RS, Grant MD. Hepatitis C virus-infected cells downregulate NKp30 and inhibit ex vivo NK cell functions. J Immunol 2013; 191:3308-18. [PMID: 23960237 DOI: 10.4049/jimmunol.1300164] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hepatitis C virus (HCV) successfully evades the immune system and establishes chronic infection in ∼80% of cases. Immune evasion may involve modulating NK cell functions. Therefore, we developed a short-term assay to assess immediate effects of HCV-infected cells on ex vivo NK cytotoxicity and cytokine production. Natural cytotoxicity, Ab-dependent cell-mediated cytotoxicity, IFN-γ production, and TNF-α production were all significantly inhibited by short-term direct exposure to HCV-infected hepatoma-derived Huh-7.5 cells. Inhibition required cell-to-cell contact and increased together with multiplicity of infection and HCV protein levels. Blocking potential interaction between HCV E2 and NK CD81 did not abrogate NK cell inhibition mediated by HCV-infected cells. We observed no change in expression levels of NKG2D, NKG2A, NKp46, or CD16 on NK cells exposed to HCV-infected Huh-7.5 cells for 5 h or of human histocompatibility-linked leukocyte Ag E on HCV-infected compared with uninfected Huh-7.5 cells. Inhibition of ex vivo NK functions did correspond with reduced surface expression of the natural cytotoxicity receptor NKp30, and downregulation of NKp30 was functionally reflected in reduced anti-NKp30 redirected lysis of P815 cells. Infection of Huh-7.5 cells with HCV JFH1(T) increased surface binding of an NKp30-IgG1 Fcγ fusion protein, suggesting upregulation of an antagonistic NKp30 ligand on HCV-infected cells. Our assay demonstrates rapid inhibition of critical NK cell functions by HCV-infected cells. Similar localized effects in vivo may contribute to establishment of chronic HCV infection and associated phenotypic and functional changes in the NK population.
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Affiliation(s)
- Kayla A Holder
- Division of BioMedical Sciences, Immunology and Infectious Diseases Program, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3V6, Canada
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Bonander N, Jamshad M, Oberthür D, Clare M, Barwell J, Hu K, Farquhar MJ, Stamataki Z, Harris HJ, Dierks K, Dafforn TR, Betzel C, McKeating JA, Bill RM. Production, purification and characterization of recombinant, full-length human claudin-1. PLoS One 2013; 8:e64517. [PMID: 23704991 PMCID: PMC3660353 DOI: 10.1371/journal.pone.0064517] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 04/16/2013] [Indexed: 01/20/2023] Open
Abstract
The transmembrane domain proteins of the claudin superfamily are the major structural components of cellular tight junctions. One family member, claudin-1, also associates with tetraspanin CD81 as part of a receptor complex that is essential for hepatitis C virus (HCV) infection of the liver. To understand the molecular basis of claudin-1/CD81 association we previously produced and purified milligram quantities of functional, full-length CD81, which binds a soluble form of HCV E2 glycoprotein (sE2). Here we report the production, purification and characterization of claudin-1. Both yeast membrane-bound and detergent-extracted, purified claudin-1 were antigenic and recognized by specific antibodies. Analytical ultracentrifugation demonstrated that extraction with n-octyl-β-d-glucopyranoside yielded monodispersed, dimeric pools of claudin-1 while extraction with profoldin-8 or n-decylphosphocholine yielded a dynamic mixture of claudin-1 oligomers. Neither form bound sE2 in line with literature expectations, while further functional analysis was hampered by the finding that incorporation of claudin-1 into proteoliposomes rendered them intractable to study. Dynamic light scattering demonstrated that claudin-1 oligomers associate with CD81 in vitro in a defined molar ratio of 1∶2 and that complex formation was enhanced by the presence of cholesteryl hemisuccinate. Attempts to assay the complex biologically were limited by our finding that claudin-1 affects the properties of proteoliposomes. We conclude that recombinant, correctly-folded, full-length claudin-1 can be produced in yeast membranes, that it can be extracted in different oligomeric forms that do not bind sE2 and that a dynamic preparation can form a specific complex with CD81 in vitro in the absence of any other cellular components. These findings pave the way for the structural characterization of claudin-1 alone and in complex with CD81.
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Affiliation(s)
- Nicklas Bonander
- School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham, United Kingdom
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Hsu SH, Yeh ML, Wang SN. New insights in recurrent HCV infection after liver transplantation. Clin Dev Immunol. 2013;2013:890517. [PMID: 23710205 PMCID: PMC3655463 DOI: 10.1155/2013/890517] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 03/17/2013] [Accepted: 03/31/2013] [Indexed: 12/15/2022]
Abstract
Hepatitis C virus (HCV) is a small-enveloped RNA virus belonging to the Flaviviridae family. Since first identified in 1989, HCV has been estimated to infect 170 million people worldwide. Mostly chronic hepatitis C virus has a uniform natural history, from liver cirrhosis to the development of hepatocellular carcinoma. The current therapy for HCV infection consists of a combination of Pegylated interferon and ribavirin. On the other hand, HCV-related liver disease is also the leading indication for liver transplantation. However, posttransplant HCV re-infection of the graft has been reported to be universal. Furthermore, the graft after HCV re-infection often results in accelerated progression to liver failure. In addition, treatment of recurrent HCV infection after liver transplantation is often compromised by enhanced adverse effects and limited efficacy of interferon-based therapies. Taken together, poor outcome after HCV re-infection, regardless of grafts or recipients, poses a major issue for the hepatologists and transplant surgeons. The aim of this paper is to review several specific aspects regarding HCV re-infection after transplant: risk factors, current therapeutics for HCV in different stages of liver transplantation, cellular function of HCV proteins, and molecular mechanisms of HCV entry. Hopefully, this paper will inspire new strategies and novel inhibitors against recurrent HCV infection after liver transplantation and greatly improve its overall outcome.
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Sourisseau M, Michta ML, Zony C, Israelow B, Hopcraft SE, Narbus CM, Parra Martín A, Evans MJ. Temporal analysis of hepatitis C virus cell entry with occludin directed blocking antibodies. PLoS Pathog. 2013;9:e1003244. [PMID: 23555257 PMCID: PMC3605286 DOI: 10.1371/journal.ppat.1003244] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 01/28/2013] [Indexed: 12/12/2022] Open
Abstract
Hepatitis C virus (HCV) is a major cause of liver disease worldwide. A better understanding of its life cycle, including the process of host cell entry, is important for the development of HCV therapies and model systems. Based on the requirement for numerous host factors, including the two tight junction proteins claudin-1 (CLDN1) and occludin (OCLN), HCV cell entry has been proposed to be a multi-step process. The lack of OCLN-specific inhibitors has prevented a comprehensive analysis of this process. To study the role of OCLN in HCV cell entry, we created OCLN mutants whose HCV cell entry activities could be inhibited by antibodies. These mutants were expressed in polarized HepG2 cells engineered to support the complete HCV life cycle by CD81 and miR-122 expression and synchronized infection assays were performed to define the kinetics of HCV cell entry. During these studies, OCLN utilization differences between HCV isolates were observed, supporting a model that HCV directly interacts with OCLN. In HepG2 cells, both HCV cell entry and tight junction formation were impaired by OCLN silencing and restored by expression of antibody regulatable OCLN mutant. Synchronized infection assays showed that glycosaminoglycans and SR-BI mediated host cell binding, while CD81, CLDN1 and OCLN all acted sequentially at a post-binding stage prior to endosomal acidification. These results fit a model where the tight junction region is the last to be encountered by the virion prior to internalization. HCV is a serious public health problem. Although new treatments have recently become available, it is clear that effective therapies will require combinations of inhibitors targeting diverse stages of the viral life cycle. While the HCV cell entry process is considered a suitable antiviral target, a lack of understanding of this process has hampered the development of inhibitors. It is widely accepted that HCV cell entry requires many cellular proteins that are used in a nonredundant and sequential manner. However, a critical piece of information supporting this model – the determination of when OCLN is used during this process – could not be addressed due to a lack of reagents that specifically target this protein. In this study, we derive mutant OCLN proteins whose HCV cell entry activity can be blocked by incubation with an antibody. These mutants allowed us to show that OCLN is used very late in the HCV cell entry process, which fits a model in which tight junction components are required later in the process than more exposed factors. Furthermore, our studies suggest that HCV virions may interact directly with OCLN, which has thus far not been demonstrated experimentally.
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Abstract
INTRODUCTION Hepatitis C virus (HCV) is a major cause of liver disease worldwide and the leading indication for liver transplantation in the United States. Current treatment options are expensive, not effective in all patients and are associated with serious side effects. Although preclinical, anti-HCV drug screening is still hampered by the lack of readily infectable small animal models, the development of cell culture HCV experimental model systems has driven a promising new wave of HCV antiviral drug discovery. AREAS COVERED This review contains a concise overview of current HCV treatment options and limitations with a subsequent in-depth focus on the available experimental models and novel strategies that have, and continue to enable, important advances in HCV drug development. EXPERT OPINION With a large cohort of chronically HCV-infected patients progressively developing liver disease that puts them at risk for hepatocellular carcinoma and hepatic decompensation, there is an urgent need to develop effective therapeutics that are well tolerated and effective in all patients and against all HCV genotypes. Significant advances in HCV experimental model development have expedited drug discovery; however, additional progress is needed. Importantly, the current trends and momentum in the field suggests that we will continue to overcome critical experimental challenges to reach this end goal.
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Affiliation(s)
- Snawar Hussain
- University of Illinois at Chicago, Department of Medicine, Chicago, IL 60612, USA
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Suzuki R, Saito K, Kato T, Shirakura M, Akazawa D, Ishii K, Aizaki H, Kanegae Y, Matsuura Y, Saito I, Wakita T, Suzuki T. Trans-complemented hepatitis C virus particles as a versatile tool for study of virus assembly and infection. Virology 2012; 432:29-38. [PMID: 22727832 DOI: 10.1016/j.virol.2012.05.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 04/23/2012] [Accepted: 05/25/2012] [Indexed: 01/28/2023]
Abstract
In this study, we compared the entry processes of trans-complemented hepatitis C virus particles (HCVtcp), cell culture-produced HCV (HCVcc) and HCV pseudoparticles (HCVpp). Anti-CD81 antibody reduced the entry of HCVtcp and HCVcc to almost background levels, and that of HCVpp by approximately 50%. Apolipoprotein E-dependent infection was observed with HCVtcp and HCVcc, but not with HCVpp, suggesting that the HCVtcp system is more relevant as a model of HCV infection than HCVpp. We improved the productivity of HCVtcp by introducing adapted mutations and by deleting sequences not required for replication from the subgenomic replicon construct. Furthermore, blind passage of the HCVtcp in packaging cells resulted in a novel mutation in the NS3 region, N1586D, which contributed to assembly of infectious virus. These results demonstrate that our plasmid-based system for efficient production of HCVtcp is beneficial for studying HCV life cycles, particularly in viral assembly and infection.
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Affiliation(s)
- Ryosuke Suzuki
- Department of Virology II, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
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Meredith LW, Wilson GK, Fletcher NF, McKeating JA. Hepatitis C virus entry: beyond receptors. Rev Med Virol 2012; 22:182-93. [PMID: 22392805 DOI: 10.1002/rmv.723] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Revised: 09/30/2011] [Accepted: 10/09/2011] [Indexed: 12/11/2022]
Abstract
HCV is a blood-borne pathogen that affects approximately 3% of the global population and leads to progressive liver disease. Recent advances have identified an essential role for host cell molecules: tetraspanin CD81, scavenger receptor B1 and the tight junction proteins claudin-1 and occludin in HCV entry, suggesting a complex multi-step process. The conserved nature of this receptor-dependent step in the viral life cycle offers an attractive target for therapeutic intervention. Evidence is emerging that additional factors other than classical receptors, such as inflammatory mediators regulate the ability of hepatocytes to support HCV entry, and as such may provide potential avenues for drug design and development. In this review, we summarise the recent literature on HCV entry mechanisms with a view to realising the future potential of therapeutically targeting this process.
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Affiliation(s)
- Luke W Meredith
- Institute for Biomedical Research, University of Birmingham, Birmingham, UK
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Sainz B, Barretto N, Yu X, Corcoran P, Uprichard SL. Permissiveness of human hepatoma cell lines for HCV infection. Virol J 2012; 9:30. [PMID: 22273112 PMCID: PMC3317838 DOI: 10.1186/1743-422x-9-30] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 01/24/2012] [Indexed: 12/27/2022] Open
Abstract
Background Although primary and established human hepatoma cell lines have been evaluated for hepatitis C virus (HCV) infection in vitro, thus far only Huh7 cells have been found to be highly permissive for infectious HCV. Since our understanding of the HCV lifecycle would benefit from the identification of additional permissive cell lines, we assembled a panel of hepatic and non-hepatic cell lines and assessed their ability to support HCV infection. Here we show infection of the human hepatoma cell lines PLC/PRF/5 and Hep3B with cell culture-derived HCV (HCVcc), albeit to lower levels than that achieved in Huh7 cells. To better understand the reduced permissiveness of PLC and Hep3B cells for HCVcc infection, we performed studies to evaluate the ability of each cell line to support specific steps of the viral lifecycle (i.e. entry, replication, egress and spread). Results We found that while the early events in HCV infection (i.e. entry plus replication initiation) are cumulatively equivalent or only marginally reduced in PLC and Hep3B cells, later steps of the viral life cycle such as steady-state replication, de novo virus production and/or spread are impaired to different degrees in PLC and Hep3B cultures compared to Huh7 cell cultures. Interestingly, we also observed that interferon stimulated gene (i.e. ISG56) expression was significantly and differentially up-regulated in PLC and Hep3B cells following viral infection. Conclusions We conclude that the restrictions observed later during HCV infection in these cell lines could in part be attributed to HCV-induced innate signaling. Nevertheless, the identification of two new cell lines capable of supporting authentic HCVcc infection, even at reduced levels, expands the current repertoire of cell lines amendable for the study of HCV in vitro and should aid in further elucidating HCV biology and the cellular determinants that modulate HCV infection.
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Affiliation(s)
- Bruno Sainz
- Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
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Wilson GK, Stamataki Z. In vitro systems for the study of hepatitis C virus infection. Int J Hepatol 2012; 2012:292591. [PMID: 23056952 DOI: 10.1155/2012/292591] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 07/03/2012] [Accepted: 07/17/2012] [Indexed: 12/22/2022] Open
Abstract
The study of a virus is made possible by the availability of culture systems in which the viral lifecycle can be realized. Such systems support robust virus entry, replication, assembly, and secretion of nascent virions. Furthermore, culture models provide a platform in which therapeutic interventions can be devised or monitored. Hepatitis C virus (HCV) has a restricted tropism to human and chimpanzees; thus investigations of HCV biology have been hindered for many years due to a lack of small animal models. Nevertheless, significant efforts have been directed at developing cell culture models to elucidate the viral lifecycle in vitro. HCV primarily infects liver parenchymal cells commonly known as hepatocytes. The liver is a highly specialized and complex organ and the development of in vitro systems that reflects this complexity has proven difficult. Consequently, host cell receptor molecules that potentiate HCV infection were identified over a decade after the virus was discovered. A summary of the various HCV in vitro culture models, their advantages, and disadvantages are described.
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Glisic S, Veljkovic N, Jovanovic Cupic S, Vasiljevic N, Prljic J, Gemovic B, Perovic V, Veljkovic V. Assessment of Hepatitis C Virus Protein Sequences with Regard to Interferon/Ribavirin Combination Therapy Response in Patients with HCV Genotype 1b. Protein J 2011; 31:129-36. [PMID: 22170451 DOI: 10.1007/s10930-011-9381-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Sharma NR, Mateu G, Dreux M, Grakoui A, Cosset FL, Melikyan GB. Hepatitis C virus is primed by CD81 protein for low pH-dependent fusion. J Biol Chem 2011; 286:30361-30376. [PMID: 21737455 DOI: 10.1074/jbc.m111.263350] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hepatitis C virus (HCV) entry into permissive cells is a complex process that involves interactions with at least four co-factors followed by endocytosis and low pH-dependent fusion with endosomes. The precise sequence of receptor engagement and their roles in promoting HCV E1E2 glycoprotein-mediated fusion are poorly characterized. Because cell-free HCV tolerates an acidic environment, we hypothesized that binding to one or more receptors on the cell surface renders E1E2 competent to undergo low pH-induced conformational changes and promote fusion with endosomes. To test this hypothesis, we examined the effects of low pH and of the second extracellular loop (ECL2) of CD81, one of the four entry factors, on HCV infectivity. Pretreatment with an acidic buffer or with ECL2 enhanced infection through changing the E1E2 conformation, as evidenced by the altered reactivity of these proteins with conformation-specific antibodies and stable association with liposomes. However, neither of the two treatments alone permitted direct fusion with the cell plasma membrane. Sequential HCV preincubation with ECL2 and acidic buffer in the absence of target cells resulted in a marked loss of infectivity, implying that the receptor-bound HCV is primed for low pH-dependent conformational changes. Indeed, soluble receptor-pretreated HCV fused with the cell plasma membrane at low pH under conditions blocking an endocytic entry pathway. These findings suggest that CD81 primes HCV for low pH-dependent fusion early in the entry process. The simple triggering paradigm and intermediate conformations of E1E2 identified in this study could help guide future vaccine and therapeutic efforts to block HCV infection.
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Affiliation(s)
- Nishi R Sharma
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia 30322
| | - Guaniri Mateu
- Division of Infectious Diseases, Department of Medicine, Lyon, F-69007, France
| | - Marlene Dreux
- Université de Lyon, UCB-Lyon1, IFR128, Lyon, F-69007, France; INSERM, U758, Lyon, F-69364, France; Ecole Normale Supérieure de Lyon, Lyon, F-69364, France
| | - Arash Grakoui
- Division of Infectious Diseases, Department of Medicine, Lyon, F-69007, France
| | - François-Loïc Cosset
- Université de Lyon, UCB-Lyon1, IFR128, Lyon, F-69007, France; INSERM, U758, Lyon, F-69364, France; Ecole Normale Supérieure de Lyon, Lyon, F-69364, France
| | - Gregory B Melikyan
- Division of Pediatric Infectious Diseases, Emory University Children's Center, Atlanta, Georgia 30322; Children's Healthcare of Atlanta, Atlanta, Georgia 30322.
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Bonander N, Jamshad M, Hu K, Farquhar MJ, Stamataki Z, Balfe P, McKeating JA, Bill RM. Structural characterization of CD81-Claudin-1 hepatitis C virus receptor complexes. Biochem Soc Trans 2011; 39:537-40. [PMID: 21428935 DOI: 10.1042/BST0390537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Tetraspanins are thought to exert their biological function(s) by co-ordinating the lateral movement and trafficking of associated molecules into tetraspanin-enriched microdomains. A second four-TM (transmembrane) domain protein family, the Claudin superfamily, is the major structural component of cellular TJs (tight junctions). Although the Claudin family displays low sequence homology and appears to be evolutionarily distinct from the tetraspanins, CD81 and Claudin-1 are critical molecules defining HCV (hepatitis C virus) entry; we recently demonstrated that CD81-Claudin-1 complexes have an essential role in this process. To understand the molecular basis of CD81-Claudin-1 complex formation, we produced and purified milligram quantities of full-length CD81 and Claudin-1, alone and in complex, in both detergent and lipid contexts. Structural characterization of these purified proteins will allow us to define the mechanism(s) underlying virus-cell interactions and aid the design of therapeutic agents targeting early steps in the viral life cycle.
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Torresi J, Johnson D, Wedemeyer H. Progress in the development of preventive and therapeutic vaccines for hepatitis C virus. J Hepatol 2011; 54:1273-85. [PMID: 21236312 DOI: 10.1016/j.jhep.2010.09.040] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 08/27/2010] [Accepted: 09/07/2010] [Indexed: 12/16/2022]
Abstract
Hepatitis C virus (HCV) is a blood borne disease estimated to chronically infect 3% of the worlds' population causing significant morbidity and mortality. Current medical therapy is curative in approximately 50% of patients. While recent treatment advances of genotype 1 infection using directly acting antiviral agents (DAAs) are encouraging, there is still a need to develop vaccine strategies capable of preventing infection. Moreover, vaccines may also be used in future in combination with DAAs enabling interferon-free treatment regimens. Viral and host specific factors contribute to viral evasion and present important impediments to vaccine development. Both, innate and adaptive immune responses are of major importance for the control of HCV infection. However, HCV has evolved ways of evading the host's immune response in order to establish persistent infection. For example, HCV inhibits intracellular interferon signalling pathways, impairs the activation of dendritic cells, CD8(+) and CD4(+) T cell responses, induces a state of T-cell exhaustion and selects escape variants with mutations CD8(+) T cell epitopes. An effective vaccine will need to produce strong and broadly cross-reactive CD4(+), CD8(+) T cell and neutralising antibody (NAb) responses to be successful in preventing or clearing HCV. Vaccines in clinical trials now include recombinant proteins, synthetic peptides, virosome based vaccines, tarmogens, modified vaccinia Ankara based vaccines, and DNA based vaccines. Several preclinical vaccine strategies are also under development and include recombinant adenoviral vaccines, virus like particles, and synthetic peptide vaccines. This paper will review the vaccines strategies employed, their success to date and future directions of vaccine design.
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Affiliation(s)
- Joseph Torresi
- Austin Centre for Infection Research, Department of Infectious Diseases Austin Hospital, Heidelberg, Victoria 3084, Australia.
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