1
|
Doherty JS, Kirkegaard K. Differential inhibition of intra- and inter-molecular protease cleavages by antiviral compounds. J Virol 2023; 97:e0092823. [PMID: 38047713 PMCID: PMC10734437 DOI: 10.1128/jvi.00928-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/27/2023] [Indexed: 12/05/2023] Open
Abstract
IMPORTANCE Most protease-targeted antiviral development evaluates the ability of small molecules to inhibit the cleavage of artificial substrates. However, before they can cleave any other substrates, viral proteases need to cleave themselves out of the viral polyprotein in which they have been translated. This can occur either intra- or inter-molecularly. Whether this process occurs intra- or inter-molecularly has implications for the potential for precursors to accumulate and for the effectiveness of antiviral drugs. We argue that evaluating candidate antivirals for their ability to block these cleavages is vital to drug development because the buildup of uncleaved precursors can be inhibitory to the virus and potentially suppress the selection of drug-resistant variants.
Collapse
Affiliation(s)
| | - Karla Kirkegaard
- Department of Genetics, Stanford University, Palo Alto, California, USA
- Department of Microbiology and Immunology, Stanford University, Palo Alto, California, USA
| |
Collapse
|
2
|
Isken O, Walther T, Wong-Dilworth L, Rehders D, Redecke L, Tautz N. Identification of NS2 determinants stimulating intrinsic HCV NS2 protease activity. PLoS Pathog 2022; 18:e1010644. [PMID: 35727826 PMCID: PMC9249167 DOI: 10.1371/journal.ppat.1010644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/01/2022] [Accepted: 06/02/2022] [Indexed: 11/19/2022] Open
Abstract
Hepatitis C Virus NS2-NS3 cleavage is mediated by NS2 autoprotease (NS2pro) and this cleavage is important for genome replication and virus assembly. Efficient NS2-NS3 cleavage relies on the stimulation of an intrinsic NS2pro activity by the NS3 protease domain. NS2pro activation depends on conserved hydrophobic NS3 surface residues and yet unknown NS2-NS3 surface interactions. Guided by an in silico NS2-NS3 precursor model, we experimentally identified two NS2 surface residues, F103 and L144, that are important for NS2pro activation by NS3. When analyzed in the absence of NS3, a combination of defined amino acid exchanges, namely F103A and L144I, acts together to increase intrinsic NS2pro activity. This effect is conserved between different HCV genotypes. For mutation L144I its stimulatory effect on NS2pro could be also demonstrated for two other mammalian hepaciviruses, highlighting the functional significance of this finding. We hypothesize that the two exchanges stimulating the intrinsic NS2pro activity mimic structural changes occurring during NS3-mediated NS2pro activation. Introducing these activating NS2pro mutations into a NS2-NS5B replicon reduced NS2-NS3 cleavage and RNA replication, indicating their interference with NS2-NS3 surface interactions pivotal for NS2pro activation by NS3. Data from chimeric hepaciviral NS2-NS3 precursor constructs, suggest that NS2 F103 is involved in the reception or transfer of the NS3 stimulus by NS3 P115. Accordingly, fine-tuned NS2-NS3 surface interactions are a salient feature of HCV NS2-NS3 cleavage. Together, these novel insights provide an exciting basis to dissect molecular mechanisms of NS2pro activation by NS3.
Collapse
Affiliation(s)
- Olaf Isken
- Institute of Virology and Cell Biology, University of Luebeck, Luebeck, Germany
| | - Thomas Walther
- Institute of Virology and Cell Biology, University of Luebeck, Luebeck, Germany
| | - Luis Wong-Dilworth
- Institute of Virology and Cell Biology, University of Luebeck, Luebeck, Germany
| | - Dirk Rehders
- Institute of Biochemistry, University of Luebeck, Luebeck, Germany
| | - Lars Redecke
- Institute of Biochemistry, University of Luebeck, Luebeck, Germany
- Deutsches Elektronen Synchrotron (DESY), Photon Science, Hamburg, Germany
| | - Norbert Tautz
- Institute of Virology and Cell Biology, University of Luebeck, Luebeck, Germany
- * E-mail:
| |
Collapse
|
3
|
Sequential Phosphorylation of Hepatitis C Virus NS5A Protein Requires the ATP-Binding Domain of NS3 Helicase. J Virol 2022; 96:e0010722. [PMID: 35293767 DOI: 10.1128/jvi.00107-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The propagation of the hepatitis C virus (HCV) is regulated in part by the phosphorylation of its nonstructural protein NS5A that undergoes sequential phosphorylation on several highly conserved serine residues and switches from a hypo- to a hyperphosphorylated state. Previous studies have shown that NS5A sequential phosphorylation requires NS3 encoded on the same NS3-NS4A-NS4B-NS5A polyprotein. Subtle mutations in NS3 without affecting its protease activity could affect NS5A phosphorylation. Given the ATPase domain in the NS3 COOH terminus, we tested whether NS3 participates in NS5A phosphorylation similarly to the nucleoside diphosphate kinase-like activity of the rotavirus NSP2 nucleoside triphosphatase (NTPase). Mutations in the NS3 ATP-binding motifs blunted NS5A hyperphosphorylation and phosphorylation at serines 225, 232, and 235, whereas a mutation in the RNA-binding domain did not. The phosphorylation events were not rescued with wild-type NS3 provided in trans. When provided with an NS3 ATPase-compatible ATP analog, N6-benzyl-ATP-γ-S, thiophosphorylated NS5A was detected in the cells expressing the wild-type NS3-NS5B polyprotein. The thiophosphorylation level was lower in the cells expressing NS3-NS5B with a mutation in the NS3 ATP-binding domain. In vitro assays with a synthetic peptide and purified wild-type NS3 followed by dot blotting and mass spectrometry found weak NS5A phosphorylation at serines 222 and 225 that was sensitive to an inhibitor of casein kinase Iα but not helicase. When casein kinase Iα was included in the assay, much stronger phosphorylation was observed at serines 225, 232, and 235. We concluded that NS5A sequential phosphorylation requires the ATP-binding domain of the NS3 helicase and that casein kinase Iα is a potent NS5A kinase. IMPORTANCE For more than 20 years, NS3 was known to participate in NS5A sequential phosphorylation. In the present study, we show for the first time that the ATP-binding domain of NS3 is involved in NS5A phosphorylation. In vitro assays showed that casein kinase Iα is a very potent kinase responsible for NS5A phosphorylation at serines 225, 232, and 235. Our data suggest that ATP binding by NS3 probably results in conformational changes that recruit casein kinase Iα to phosphorylate NS5A, initially at S225 and subsequently at S232 and S235. Our discovery reveals intricate requirements of the structural integrity of NS3 for NS5A hyperphosphorylation and HCV replication.
Collapse
|
4
|
Abstract
Viral proteases are diverse in structure, oligomeric state, catalytic mechanism, and substrate specificity. This chapter focuses on proteases from viruses that are relevant to human health: human immunodeficiency virus subtype 1 (HIV-1), hepatitis C (HCV), human T-cell leukemia virus type 1 (HTLV-1), flaviviruses, enteroviruses, and coronaviruses. The proteases of HIV-1 and HCV have been successfully targeted for therapeutics, with picomolar FDA-approved drugs currently used in the clinic. The proteases of HTLV-1 and the other virus families remain emerging therapeutic targets at different stages of the drug development process. This chapter provides an overview of the current knowledge on viral protease structure, mechanism, substrate recognition, and inhibition. Particular focus is placed on recent advances in understanding the molecular basis of diverse substrate recognition and resistance, which is essential toward designing novel protease inhibitors as antivirals.
Collapse
Affiliation(s)
- Jacqueto Zephyr
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, United States
| | - Nese Kurt Yilmaz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, United States
| | - Celia A Schiffer
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, United States.
| |
Collapse
|
5
|
Smith DA, Fernandez-Antunez C, Magri A, Bowden R, Chaturvedi N, Fellay J, McLauchlan J, Foster GR, Irving WL, Simmonds P, Pedergnana V, Ramirez S, Bukh J, Barnes E, Ansari MA. Viral genome wide association study identifies novel hepatitis C virus polymorphisms associated with sofosbuvir treatment failure. Nat Commun 2021; 12:6105. [PMID: 34671027 PMCID: PMC8528821 DOI: 10.1038/s41467-021-25649-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/11/2021] [Indexed: 12/12/2022] Open
Abstract
Persistent hepatitis C virus (HCV) infection is a major cause of chronic liver disease, worldwide. With the development of direct-acting antivirals, treatment of chronically infected patients has become highly effective, although a subset of patients responds less well to therapy. Sofosbuvir is a common component of current de novo or salvage combination therapies, that targets the HCV NS5B polymerase. We use pre-treatment whole-genome sequences of HCV from 507 patients infected with HCV subtype 3a and treated with sofosbuvir containing regimens to detect viral polymorphisms associated with response to treatment. We find three common polymorphisms in non-targeted HCV NS2 and NS3 proteins are associated with reduced treatment response. These polymorphisms are enriched in post-treatment HCV sequences of patients unresponsive to treatment. They are also associated with lower reductions in viral load in the first week of therapy. Using in vitro short-term dose-response assays, these polymorphisms do not cause any reduction in sofosbuvir potency, suggesting an indirect mechanism of action in decreasing sofosbuvir efficacy. The identification of polymorphisms in NS2 and NS3 proteins associated with poor treatment outcomes emphasises the value of systematic genome-wide analyses of viruses in uncovering clinically relevant polymorphisms that impact treatment.
Collapse
Affiliation(s)
- David A Smith
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 1SY, UK
| | - Carlota Fernandez-Antunez
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Andrea Magri
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 1SY, UK
| | - Rory Bowden
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Nimisha Chaturvedi
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Jacques Fellay
- School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- Precision Medicine Unit, University Hospital and University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - John McLauchlan
- MRC-University of Glasgow Centre for Virus Research, Glasgow, G61 1QH, UK
| | - Graham R Foster
- Barts Liver Centre, Blizard Institute, Queen Mary University of London, London, UK
| | - William L Irving
- NIHR Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Peter Simmonds
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 1SY, UK
| | | | - Santseharay Ramirez
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Hvidovre Hospital and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Eleanor Barnes
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 1SY, UK
| | - M Azim Ansari
- Peter Medawar Building for Pathogen Research, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 1SY, UK.
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK.
| |
Collapse
|
6
|
Li HC, Yang CH, Lo SY. Cellular factors involved in the hepatitis C virus life cycle. World J Gastroenterol 2021; 27:4555-4581. [PMID: 34366623 PMCID: PMC8326260 DOI: 10.3748/wjg.v27.i28.4555] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/04/2021] [Accepted: 07/09/2021] [Indexed: 02/06/2023] Open
Abstract
The hepatitis C virus (HCV), an obligatory intracellular pathogen, highly depends on its host cells to propagate successfully. The HCV life cycle can be simply divided into several stages including viral entry, protein translation, RNA replication, viral assembly and release. Hundreds of cellular factors involved in the HCV life cycle have been identified over more than thirty years of research. Characterization of these cellular factors has provided extensive insight into HCV replication strategies. Some of these cellular factors are targets for anti-HCV therapies. In this review, we summarize the well-characterized and recently identified cellular factors functioning at each stage of the HCV life cycle.
Collapse
Affiliation(s)
- Hui-Chun Li
- Department of Biochemistry, Tzu Chi University, Hualien 970, Taiwan
| | - Chee-Hing Yang
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien 970, Taiwan
| | - Shih-Yen Lo
- Department of Laboratory Medicine and Biotechnology, Tzu Chi University, Hualien 970, Taiwan
- Department of Laboratory Medicine, Buddhist Tzu Chi General Hospital, Hualien 970, Taiwan
| |
Collapse
|
7
|
Tarannum H, Chauhan B, Samadder A, Roy H, Nandi S. To Explore the Potential Targets and Current Structure-based Design Strategies Utilizing Co-crystallized Ligand to Combat HCV. Curr Drug Targets 2021; 22:590-604. [PMID: 32720601 DOI: 10.2174/1389450121999200727215020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 05/05/2020] [Accepted: 05/11/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Hepatitis C Virus (HCV) belongs to the Hepacivirus family. HCV has been designated as a very dreadful virus as it can attack the liver, causing inflammation and even may lead to cancer in chronic conditions. It was estimated that 71 million people around the world have chronic HCV infection. World Health Organization (WHO) reported that about 399000 people died because of chronic cirrhosis and liver cancer globally. In spite of the abundance of availability of drugs for the treatment of HCV, however, the issue of drug resistance surpasses all the possibilities of therapeutic management of HCV. Therefore, to address this issue of 'drug-resistance', various HCV targets were explored to quest the evaluation of the mechanism of the disease progression. METHODS An attempt has been made in the present study to explore the various targets of HCV involved in the mechanism(s) of the disease initiation and progression and to focus on the mode of binding of ligands, which are co-crystallized at the active cavity of different HCV targets. CONCLUSION The present study could predict some crucial features of these ligands, which possibly interacted with various amino acid residues responsible for their biological activity and molecular signaling pathway(s). Such binding mode may be considered as a template for the high throughput screening and designing of active congeneric ligands to combat HCV.
Collapse
Affiliation(s)
- Heena Tarannum
- Department of Pharmaceutical Chemistry, Global Institute of Pharmaceutical Education and Research (Affiliated to Uttarakhand Technical University), Kashipur-244713, India
| | - Bhumika Chauhan
- Department of Pharmaceutical Chemistry, Global Institute of Pharmaceutical Education and Research (Affiliated to Uttarakhand Technical University), Kashipur-244713, India
| | - Asmita Samadder
- Cytogenetics and Molecular Biology Lab., Department of Zoology, University of Kalyani, Kalyani, Nadia, 741235, India
| | - Harekrishna Roy
- Nirmala College of Pharmacy, Mangalagiri, Guntur, Andhra Pradesh, 522503, India
| | - Sisir Nandi
- Department of Pharmaceutical Chemistry, Global Institute of Pharmaceutical Education and Research (Affiliated to Uttarakhand Technical University), Kashipur-244713, India
| |
Collapse
|
8
|
Khan S, Soni S, Veerapu NS. HCV Replicon Systems: Workhorses of Drug Discovery and Resistance. Front Cell Infect Microbiol 2020; 10:325. [PMID: 32714881 PMCID: PMC7344236 DOI: 10.3389/fcimb.2020.00325] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 05/28/2020] [Indexed: 12/16/2022] Open
Abstract
The development of direct-acting antivirals (DAAs) has revolutionized the state-of-the art treatment of HCV infections, with sustained virologic response rates above 90%. However, viral variants harboring substitutions referred to as resistance-associated substitutions (RASs) may be present in baseline levels and confer resistance to DAAs, thereby posing a major challenge for HCV treatment. HCV replicons have been the primary tools for discovering and evaluating the inhibitory activity of DAAs against viral replication. Interest in replicon systems has further grown as they have become indispensable for discovering genotype-specific and cross-genotype RASs. Here, we review functional replicon systems for HCV, how these replicon systems have contributed to the development of DAAs, and the characteristics and distribution of RASs for DAAs.
Collapse
Affiliation(s)
- Shaheen Khan
- Virology Section, Department of Life Sciences, Shiv Nadar University, Gautam Buddha Nagar, India
| | - Shalini Soni
- Virology Section, Department of Life Sciences, Shiv Nadar University, Gautam Buddha Nagar, India
| | - Naga Suresh Veerapu
- Virology Section, Department of Life Sciences, Shiv Nadar University, Gautam Buddha Nagar, India
| |
Collapse
|
9
|
Plant-Derived Purification, Chemical Synthesis, and In Vitro/In Vivo Evaluation of a Resveratrol Dimer, Viniferin, as an HCV Replication Inhibitor. Viruses 2019; 11:v11100890. [PMID: 31547617 PMCID: PMC6832221 DOI: 10.3390/v11100890] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/03/2019] [Accepted: 09/20/2019] [Indexed: 02/08/2023] Open
Abstract
Oligostilbenoid compounds, a group of resveratrol multimers, display several anti-microbial activities through the neutralization of cytotoxic oxidants, and by inhibiting essential host and viral enzymes. In our previous study, we identified a series of oligostilbenoid compounds as potent hepatitis C virus (HCV) replication inhibitors. In particular, vitisin B, a resveratrol tetramer, exhibited the most dramatic anti-HCV activity (EC50 = 6 nM and CC50 > 10 μM) via the disruption of the viral helicase NS3 (IC50 = 3 nM). However, its further development as an HCV drug candidate was halted due to its intrinsic drawbacks, such as poor stability, low water solubility, and restricted in vivo absorption. In order to overcome these limitations, we focused on (+)-ε-viniferin, a resveratrol dimer, as an alternative. We prepared three different versions of (+)-ε-viniferin, including one which was extracted from the grapevine root (EVF) and two which were chemically synthesized with either penta-acetylation (SVF-5Ac) or no acetylation (SVF) using a newly established synthesis method. We confirmed their anti-HCV replication activities and minimal cytotoxicity by using genotype 1b and 2a HCV replicon cells. Their anti-HCV replication action also translated into a significant reduction of viral protein expression. Anti-HCV NS3 helicase activity by EVF was also verified in vitro. Finally, we demonstrated that SVF has improved pharmacokinetic properties over vitisin B. Overall, the favorable antiviral and pharmacokinetic properties of these three versions of viniferin warrant their further study as members of a promising new class of anti-HCV therapeutics.
Collapse
|
10
|
Chu L, Jin M, Feng C, Wang X, Zhang D. A highly divergent hepacivirus-like flavivirus in domestic ducks. J Gen Virol 2019; 100:1234-1240. [PMID: 31282853 DOI: 10.1099/jgv.0.001298] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Using random amplification and reverse transcription-PCR, a novel RNA virus was detected in sera of domestic ducks. The full genome of the virus was determined for three strains, identifying the first hepacivirus-like flavivirus in birds. The virus, that we tentatively named duck hepacivirus-like virus (DuHV), possesses several unique molecular features, such as possession of the largest hepacivirus-like polyprotein gene and a Pegivirus A-like internal ribosome entry site. Sequence comparisons and phylogenetic and sliding-window analyses indicated that DuHV is most closely related to, but highly divergent from, the known hepaciviruses. DuHV was detected in 69.7 % of 185 serum samples from four duck species and in 31 of 33 flocks from five provinces of China, reflecting a high prevalence in duck populations and a wide geographical distribution. The detection of DuHV in the same flock in November 2018 and April 2019 suggested that persistent infection can be established in the infected ducks.
Collapse
Affiliation(s)
- Lili Chu
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| | - Meiling Jin
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| | - Chonglun Feng
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| | - Xiaoyan Wang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| | - Dabing Zhang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| |
Collapse
|
11
|
Luna JM, Saeed M, Rice CM. Taming a beast: lessons from the domestication of hepatitis C virus. Curr Opin Virol 2019; 35:27-34. [PMID: 30875640 PMCID: PMC6556422 DOI: 10.1016/j.coviro.2019.02.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/05/2019] [Accepted: 02/12/2019] [Indexed: 12/13/2022]
Abstract
"What I cannot create, I do not understand." Richard Feynman may have championed reasoning from first principles in his famous blackboard missive, but he could just as well have been referring to the plight of a molecular virologist. What cannot be grown in a controlled laboratory setting, we cannot fully understand. The story of the laboratory domestication of hepatitis C virus (HCV) is now a classic example of virologists applying all manner of inventive skill to create cell-based models of infection in order to clarify prospective drug targets. In this review, we highlight key successes and failures that were instructive in achieving cell-based models for HCV studies and drug development. We also emphasize the lessons learned from the ∼40 year saga that may be applicable to viruses yet unknown and uncultured.
Collapse
Affiliation(s)
- Joseph M Luna
- The Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY, United States
| | - Mohsan Saeed
- The Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY, United States
| | - Charles M Rice
- The Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY, United States.
| |
Collapse
|
12
|
Zając M, Muszalska I, Sobczak A, Dadej A, Tomczak S, Jelińska A. Hepatitis C - New drugs and treatment prospects. Eur J Med Chem 2019; 165:225-249. [PMID: 30685524 DOI: 10.1016/j.ejmech.2019.01.025] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 01/11/2019] [Accepted: 01/11/2019] [Indexed: 12/19/2022]
Abstract
Hepatitis C virus (HCV) affects approx. 3% of the world's population and accounts for ca 300 000 deaths per year. 80% of individuals with HCV develop chronic symptoms which, when untreated, may cause cirrhosis (27%) or hepatocellular carcinoma (25%). The hepatitis C virus is a (+)ssRNA enveloped virus of the family Flaviviridae. Seven major HCV genotypes and their subtypes (a, b) have been identified. In the 1990s, interferons alpha-2 were used in the treatment of HCV and in the next decade HCV therapy was based on pegylated interferon alpha-2 in combination with ribavirin. Since 2011, interferons alpha, DNA and RNA polymerase inhibitors, NS3/4A RNA protease inhibitors, NS5 RNA serine protease inhibitors, NS5B RNA polymerase inhibitors have been approved for clinical use. Monotherapy is avoided in medication due to rapidly developing viral resistance. A total of 113 papers were included comprising original publications and reviews. The paper reviews the molecular targets and chemical structures of drugs used in HCV treatment. Indications and contraindications for anti-HCV drugs are also discussed together with application regimens.
Collapse
Affiliation(s)
- Marianna Zając
- Poznan University of Medicinal Sciences, Department of Pharmaceutical Chemistry, Grunwaldzka Str. 6, 60-780, Poznań, Poland
| | - Izabela Muszalska
- Poznan University of Medicinal Sciences, Department of Pharmaceutical Chemistry, Grunwaldzka Str. 6, 60-780, Poznań, Poland.
| | - Agnieszka Sobczak
- Poznan University of Medicinal Sciences, Department of Pharmaceutical Chemistry, Grunwaldzka Str. 6, 60-780, Poznań, Poland
| | - Adrianna Dadej
- Poznan University of Medicinal Sciences, Department of Pharmaceutical Chemistry, Grunwaldzka Str. 6, 60-780, Poznań, Poland
| | - Szymon Tomczak
- Poznan University of Medicinal Sciences, Department of Pharmaceutical Chemistry, Grunwaldzka Str. 6, 60-780, Poznań, Poland
| | - Anna Jelińska
- Poznan University of Medicinal Sciences, Department of Pharmaceutical Chemistry, Grunwaldzka Str. 6, 60-780, Poznań, Poland
| |
Collapse
|
13
|
Hepatitis C virus cell culture models: an encomium on basic research paving the road to therapy development. Med Microbiol Immunol 2018; 208:3-24. [PMID: 30298360 DOI: 10.1007/s00430-018-0566-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/01/2018] [Indexed: 12/17/2022]
Abstract
Chronic hepatitis C virus (HCV) infections affect 71 million people worldwide, often resulting in severe liver damage. Since 2014 highly efficient therapies based on directly acting antivirals (DAAs) are available, offering cure rates of almost 100%, if the infection is diagnosed in time. It took more than a decade to discover HCV in 1989 and another decade to establish a cell culture model. This review provides a personal view on the importance of HCV cell culture models, particularly the replicon system, in the process of therapy development, from drug screening to understanding of mode of action and resistance, with a special emphasis on the contributions of Ralf Bartenschlager's group. It summarizes the tremendous efforts of scientists in academia and industry required to achieve efficient DAAs, focusing on the main targets, protease, polymerase and NS5A. It furthermore underpins the importance of strong basic research laying the ground for translational medicine.
Collapse
|
14
|
Gauna A, Losada S, Lorenzo M, Toledo M, Bermúdez H, D'Angelo P, Sánchez D, Noya O. Use of Synthetic Peptides and Multiple Antigen Blot Assay in the Immunodiagnosis of Hepatitis C Virus Infection. Viral Immunol 2018; 31:568-574. [PMID: 30256730 DOI: 10.1089/vim.2018.0023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Acute hepatitis C virus (HCV) infection is usually asymptomatic, therefore, early diagnosis is rare. It may remain undiagnosed in individuals who progress to chronic infection, often until serious liver damage has developed. To incorporate the diagnosis of this viral disease in a multiple-diagnostic assay, we first analyzed by immunoinformatics the HCV subtype 1a polyprotein (specifically Core, E2, NS3, NS5A proteins) to select antigenic peptides to be tested initially by the Pepscan technique. Next, we performed the immunodiagnosis of HCV infection, using the Multiple Antigen Blot Assay (MABA). In 22 patients' sera included in this study, a 20-mer linear peptide belonging to the N-terminus of the worldwide conserved Core protein showed 100% sensitivity and specificity; other sequences showed different levels of antibody recognition. The use of MABA in combination with synthetic peptides as a source of multiple, specific, and nonexpensive antigens for other infectious diseases could represent a rapid, integrated, and inexpensive diagnostic methodology.
Collapse
Affiliation(s)
- Adriana Gauna
- 1 Programa de Doctorado en Biotecnología, Pontificia Universidad Católica de Valparaíso/Universidad Técnica Federico Santa María , Valparaíso, Chile
| | - Sandra Losada
- 2 Sección de Biohelmintiasis, Instituto de Medicina Tropical , Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela
| | - María Lorenzo
- 2 Sección de Biohelmintiasis, Instituto de Medicina Tropical , Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela
| | - Marilyan Toledo
- 3 Cátedra de Parasitología, Escuela de Medicina "Luis Razetti," Universidad Central de Venezuela , Caracas, Venezuela
| | - Henry Bermúdez
- 2 Sección de Biohelmintiasis, Instituto de Medicina Tropical , Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela
| | - Pierina D'Angelo
- 4 Laboratorio de Programas Especiales-Hepatitis y SIDA, Dpto de Virología, Gerencia Sectorial de Diagnóstico y Vigilancia Epidemiológica, Instituto Nacional de Higiene "Rafael Rangel ," Caracas, Venezuela
| | - Doneyla Sánchez
- 4 Laboratorio de Programas Especiales-Hepatitis y SIDA, Dpto de Virología, Gerencia Sectorial de Diagnóstico y Vigilancia Epidemiológica, Instituto Nacional de Higiene "Rafael Rangel ," Caracas, Venezuela
| | - Oscar Noya
- 2 Sección de Biohelmintiasis, Instituto de Medicina Tropical , Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela .,5 Centro para Estudios Sobre Malaria, Instituto de Altos Estudios "Dr. Arnoldo Gabaldón" Instituto Nacional de Higiene-Ministerio del Poder Popular para la Salud , Caracas, Venezuela
| |
Collapse
|
15
|
Kim D, Goo JI, Kim MI, Lee SJ, Choi M, Than TT, Nguyen PH, Windisch MP, Lee K, Choi Y, Lee C. Suppression of Hepatitis C Virus Genome Replication and Particle Production by a Novel Diacylglycerol Acyltransferases Inhibitor. Molecules 2018; 23:molecules23082083. [PMID: 30127285 PMCID: PMC6222871 DOI: 10.3390/molecules23082083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/01/2018] [Accepted: 08/11/2018] [Indexed: 11/23/2022] Open
Abstract
Diacylglycerol acyltransferases (DGATs) play a critical role in the biosynthesis of endogenous triglycerides (TGs) and formation of lipid droplets (LDs) in the liver. In particular, one member of DGATs, DGAT-1 was reported to be an essential host factor for the efficient production of hepatitis C virus (HCV) particles. By utilizing our previously characterized three different groups of twelve DGAT inhibitors, we found that one of the DGAT inhibitors, a 2-((4-adamantylphenoxy) methyl)-N-(furan-2-ylmethyl)-1H-benzo[d]imidazole-5-carboxam (10j) is a potent suppressor of both HCV genome replication and particle production. 10j was able to induce inhibition of these two critical viral functions in a mutually separate manner. Abrogation of the viral genome replication by 10j led to a significant reduction in the viral protein expression as well. Interestingly, we found that its antiviral effect did not depend on the reduction of TG biosynthesis by 10j. This suggests that the inhibitory activity of 10j against DGATs may not be directly related with its antiviral action.
Collapse
Affiliation(s)
- Dahee Kim
- College of Pharmacy, Dongguk University, Goyang 10326, Korea.
| | - Ja-Il Goo
- School of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea.
| | - Mi Il Kim
- College of Pharmacy, Dongguk University, Goyang 10326, Korea.
| | - Sung-Jin Lee
- College of Pharmacy, Dongguk University, Goyang 10326, Korea.
| | - Moonju Choi
- College of Pharmacy, Dongguk University, Goyang 10326, Korea.
| | - Thoa Thi Than
- Hepatitis Research Laboratory, Department of Applied Molecular Virology, Institut Pasteur Korea, 696, Seongnam 13488, Korea.
| | - Phuong Hong Nguyen
- Hepatitis Research Laboratory, Department of Applied Molecular Virology, Institut Pasteur Korea, 696, Seongnam 13488, Korea.
| | - Marc P Windisch
- Hepatitis Research Laboratory, Department of Applied Molecular Virology, Institut Pasteur Korea, 696, Seongnam 13488, Korea.
| | - Kyeong Lee
- College of Pharmacy, Dongguk University, Goyang 10326, Korea.
| | - Yongseok Choi
- School of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea.
| | - Choongho Lee
- College of Pharmacy, Dongguk University, Goyang 10326, Korea.
| |
Collapse
|
16
|
Boukadida C, Fritz M, Blumen B, Fogeron ML, Penin F, Martin A. NS2 proteases from hepatitis C virus and related hepaciviruses share composite active sites and previously unrecognized intrinsic proteolytic activities. PLoS Pathog 2018; 14:e1006863. [PMID: 29415072 PMCID: PMC5819835 DOI: 10.1371/journal.ppat.1006863] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 02/20/2018] [Accepted: 01/08/2018] [Indexed: 12/17/2022] Open
Abstract
Over the recent years, several homologues with varying degrees of genetic relatedness to hepatitis C virus (HCV) have been identified in a wide range of mammalian species. HCV infectious life cycle relies on a first critical proteolytic event of its single polyprotein, which is carried out by nonstructural protein 2 (NS2) and allows replicase assembly and genome replication. In this study, we characterized and evaluated the conservation of the proteolytic mode of action and regulatory mechanisms of NS2 across HCV and animal hepaciviruses. We first demonstrated that NS2 from equine, bat, rodent, New and Old World primate hepaciviruses also are cysteine proteases. Using tagged viral protein precursors and catalytic triad mutants, NS2 of equine NPHV and simian GBV-B, which are the most closely and distantly related viruses to HCV, respectively, were shown to function, like HCV NS2 as dimeric proteases with two composite active sites. Consistent with the reported essential role for NS3 N-terminal domain (NS3N) as HCV NS2 protease cofactor via NS3N key hydrophobic surface patch, we showed by gain/loss of function mutagenesis studies that some heterologous hepacivirus NS3N may act as cofactors for HCV NS2 provided that HCV-like hydrophobic residues are conserved. Unprecedently, however, we also observed efficient intrinsic proteolytic activity of NS2 protease in the absence of NS3 moiety in the context of C-terminal tag fusions via flexible linkers both in transiently transfected cells for all hepaciviruses studied and in the context of HCV dicistronic full-length genomes. These findings suggest that NS3N acts as a regulatory rather than essential cofactor for hepacivirus NS2 protease. Overall, unique features of NS2 including enzymatic function as dimers with two composite active sites and additional NS3-independent proteolytic activity are conserved across hepaciviruses regardless of their genetic distances, highlighting their functional significance in hepacivirus life cycle. Despite remarkable progress in the development of therapeutic options, more than 70 million individuals are chronically infected by hepatitis C virus (HCV) worldwide and major challenges in basic and translational research remain. Phylogenetically-related HCV homologues have recently been identified in the wild in several mammalian species, whose host restriction and potential for zoonosis remain largely unknown. We comparatively characterized the functions and properties of nonstructural proteins 2 (NS2) from several animal hepaciviruses and HCV. We demonstrated that NS2 from animal hepaciviruses, like HCV NS2, are cysteine proteases, which function as dimers with two composite active sites to ensure a key proteolytic event of the single viral polyprotein at the NS2/NS3 junction. In addition to the activation of HCV NS2 protease by NS3 N-terminal domain, our data revealed a novel NS3-independent substrate specificity and efficient intrinsic proteolytic activity of NS2. The conservation of its properties and peculiar mode of action among distantly related hepaciviruses supports an important regulatory role for NS2 protein in the life cycle of these viruses. It also strengthens the value of animal, notably rodent hepaciviruses for the development of surrogate, immunocompetent models of HCV infection to address HCV-associated pathogenesis and vaccine strategies.
Collapse
Affiliation(s)
- Célia Boukadida
- Institut Pasteur, Unité de Génétique Moléculaire des Virus à ARN, Paris, France
- CNRS UMR 3569, Paris, France
- Université Paris Diderot–Sorbonne Paris Cité, Paris, France
| | - Matthieu Fritz
- Institut Pasteur, Unité de Génétique Moléculaire des Virus à ARN, Paris, France
- CNRS UMR 3569, Paris, France
- Université Paris Diderot–Sorbonne Paris Cité, Paris, France
| | - Brigitte Blumen
- Institut Pasteur, Unité de Génétique Moléculaire des Virus à ARN, Paris, France
- CNRS UMR 3569, Paris, France
- Université Paris Diderot–Sorbonne Paris Cité, Paris, France
| | - Marie-Laure Fogeron
- Institut de Biologie et Chimie des Protéines, Molecular Microbiology and Structural Biochemistry, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, Lyon, France
| | - François Penin
- Institut de Biologie et Chimie des Protéines, Molecular Microbiology and Structural Biochemistry, Labex Ecofect, UMR 5086 CNRS, Université de Lyon, Lyon, France
| | - Annette Martin
- Institut Pasteur, Unité de Génétique Moléculaire des Virus à ARN, Paris, France
- CNRS UMR 3569, Paris, France
- Université Paris Diderot–Sorbonne Paris Cité, Paris, France
- * E-mail:
| |
Collapse
|
17
|
Goonawardane N, Ross-Thriepland D, Harris M. Regulation of hepatitis C virus replication via threonine phosphorylation of the NS5A protein. J Gen Virol 2017; 99:62-72. [PMID: 29139348 PMCID: PMC5882090 DOI: 10.1099/jgv.0.000975] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The hepatitis C virus non-structural 5A (NS5A) protein is highly phosphorylated and plays roles in both virus genome replication and assembly of infectious virus particles. NS5A comprises three domains separated by low complexity sequences (LCS). Mass spectrometry analysis of NS5A revealed the existence of a singly phosphorylated tryptic peptide corresponding to the end of LCS I and the beginning of domain II that contained a number of potential phosphorylatable residues (serines and threonines). Here we use a mutagenic approach to investigate the potential role of three of these threonine residues. Phosphomimetic mutations of two of these (T242E and T244E) resulted in significant reductions in virus genome replication and the production of infectious virus, suggesting that the phosphorylation of these residues negatively regulated virus RNA synthesis. Mutation of T245 had no effect, however when T245E was combined with the other two phosphomimetic mutations (TripleE) the inhibitory effect on replication was less pronounced. Effects of the mutations on the ratio of basally/hyperphosphorylated NS5A, together with the apparent molecular weight of the basally phosphorylated species were also observed. Lastly, two of the mutations (T245A and TripleE) resulted in a perinuclear restricted localization of NS5A. These data add further complexity to NS5A phosphorylation and suggest that this analysis be extended outwith the serine-rich cluster within LCS I.
Collapse
Affiliation(s)
- Niluka Goonawardane
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Douglas Ross-Thriepland
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK.,Present address: AstraZeneca, Cambridge Biomedical Campus, Cambridge, CB20AA, UK
| | - Mark Harris
- School of Molecular and Cellular Biology, Faculty of Biological Sciences and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| |
Collapse
|
18
|
Lei J, Hilgenfeld R. RNA-virus proteases counteracting host innate immunity. FEBS Lett 2017; 591:3190-3210. [PMID: 28850669 PMCID: PMC7163997 DOI: 10.1002/1873-3468.12827] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/21/2017] [Accepted: 08/22/2017] [Indexed: 01/20/2023]
Abstract
Virus invasion triggers host immune responses, in particular, innate immune responses. Pathogen‐associated molecular patterns of viruses (such as dsRNA, ssRNA, or viral proteins) released during virus replication are detected by the corresponding pattern‐recognition receptors of the host, and innate immune responses are induced. Through production of type‐I and type‐III interferons as well as various other cytokines, the host innate immune system forms the frontline to protect host cells and inhibit virus infection. Not surprisingly, viruses have evolved diverse strategies to counter this antiviral system. In this review, we discuss the multiple strategies used by proteases of positive‐sense single‐stranded RNA viruses of the families Picornaviridae, Coronaviridae, and Flaviviridae, when counteracting host innate immune responses.
Collapse
Affiliation(s)
- Jian Lei
- Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Germany
| | - Rolf Hilgenfeld
- Institute of Biochemistry, Center for Structural and Cell Biology in Medicine, University of Lübeck, Germany.,German Center for Infection Research (DZIF), Hamburg - Lübeck - Borstel - Riems Site, University of Lübeck, Germany
| |
Collapse
|
19
|
Sudo K, Matsumoto Y, Matsushima M, Konno K, Shimotohno K, Shigeta S, Yokota T. Novel Hepatitis C virus Protease Inhibitors: 2,4,6-Trihydroxy,3-Nitro-Benzamide Derivatives. ACTA ACUST UNITED AC 2017. [DOI: 10.1177/095632029700800608] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- K Sudo
- Rational Drug Design Laboratories, 4-1-1, Misato, Matsukawa-Machi, Fukushima 960-1 2, Japan
- Department of Microbiology, Fukushima Medical College, 1 Hikarigaoka, Fukushima 960-1 2, Japan
| | - Y Matsumoto
- Rational Drug Design Laboratories, 4-1-1, Misato, Matsukawa-Machi, Fukushima 960-1 2, Japan
| | - M Matsushima
- Rational Drug Design Laboratories, 4-1-1, Misato, Matsukawa-Machi, Fukushima 960-1 2, Japan
| | - K Konno
- Rational Drug Design Laboratories, 4-1-1, Misato, Matsukawa-Machi, Fukushima 960-1 2, Japan
| | - K Shimotohno
- Institute for Virus Research, Kyoto University, Sakyo-ku Shogoin, Kyoto 606, Japan
| | - S Shigeta
- Department of Microbiology, Fukushima Medical College, 1 Hikarigaoka, Fukushima 960-1 2, Japan
| | - T Yokota
- Rational Drug Design Laboratories, 4-1-1, Misato, Matsukawa-Machi, Fukushima 960-1 2, Japan
| |
Collapse
|
20
|
Elberry MH, Darwish NHE, Mousa SA. Hepatitis C virus management: potential impact of nanotechnology. Virol J 2017; 14:88. [PMID: 28464951 PMCID: PMC5414367 DOI: 10.1186/s12985-017-0753-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 04/19/2017] [Indexed: 12/21/2022] Open
Abstract
Around 170–200 million individuals have hepatitis C virus (HCV), which represents ~ 3% of the world population, including ~ 3–5 million people in the USA. According to the WHO regional office in the Middle East, Egypt has the highest prevalence in the world, with 7% prevalence in adults. There had been no effective vaccine for HCV; a combination of PEG-Interferon and ribavirin for at least 48 weeks was the standard therapy, but it failed in more than 40% of the patients and has a high cost and serious side effects. The recent introduction of direct-acting antivirals (DAA) resulted in major advances toward the cure of HCV. However, relapse and reduced antiviral efficacy in fibrotic, cirrhotic HCV patients in addition to some undesired effects restrain the full potential of these combinations. There is a need for new approaches for the combinations of different DAA and their targeted delivery using novel nanotechnology approaches. In this review, the role of nanoparticles as a carrier for HCV vaccines, anti-HCV combinations, and their targeted delivery are discussed.
Collapse
Affiliation(s)
- Mostafa H Elberry
- The Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Rensselaer, NY, 12144, USA.,National Cancer Institute, Cairo University, Cairo, Egypt
| | - Noureldien H E Darwish
- The Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Rensselaer, NY, 12144, USA.,Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Shaker A Mousa
- The Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Rensselaer, NY, 12144, USA.
| |
Collapse
|
21
|
Abstract
Chronic infection with hepatitis C virus (HCV) is a global public health burden. It has been only several decades since this virus was first identified. In the meantime, a lot of progress has been made in the fight against HCV. Although the development of pegylated interferon (PEG-IFN) and its combination with ribavirin (RBV) has significantly increased effectiveness of IFN-based treatment, candidate patients must be assessed for eligibility prior to the treatment due to side effects of the regimens and the rates of sustained virological response (SVR) were only around 50%. In 2011, the protease inhibitor (PI) Telaprevir was firstly approved as a direct-acting antiviral (DAA) for hepatitis C. The second generation of PIs was subsequently introduced and, by adding PI to Peg-IFN/RBV, the SVR rates were found to be raised to up to 80%. Further, with the recent approval of the NS5A inhibitors and the NS5B polymerase inhibitors and with the SVR rates reaching 90% or greater using IFN-free, DAA combination regimens, it is now expected that the majority of patients with chronic hepatitis C can be cured of infection in the near future.
Collapse
|
22
|
A Point Mutation in the N-Terminal Amphipathic Helix α 0 in NS3 Promotes Hepatitis C Virus Assembly by Altering Core Localization to the Endoplasmic Reticulum and Facilitating Virus Budding. J Virol 2017; 91:JVI.02399-16. [PMID: 28053108 DOI: 10.1128/jvi.02399-16] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 12/25/2016] [Indexed: 12/22/2022] Open
Abstract
The assembly of hepatitis C virus (HCV), a complicated process in which many viral and cellular factors are involved, has not been thoroughly deciphered. NS3 is a multifunctional protein that contains an N-terminal amphipathic α helix (designated helix α0), which is crucial for the membrane association and stability of NS3 protein, followed by a serine protease domain and a C-terminal helicase/NTPase domain. NS3 participates in HCV assembly likely through its C-terminal helicase domain, in which all reported adaptive mutations enhancing virion assembly reside. In this study, we determined that the N-terminal helix α0 of NS3 may contribute to HCV assembly. We identified a single mutation from methionine to threonine at amino acid position 21 (M21T) in helix α0, which significantly promoted viral production while having no apparent effect on the membrane association and protease activity of NS3. Subsequent analyses demonstrated that the M21T mutation did not affect HCV genome replication but rather promoted virion assembly. Further study revealed a shift in the subcellular localization of core protein from lipid droplets (LD) to the endoplasmic reticulum (ER). Finally, we showed that the M21T mutation increased the colocalization of core proteins and viral envelope proteins, leading to a more efficient envelopment of viral nucleocapsids. Collectively, the results of our study revealed a new function of NS3 helix α0 and aid understanding of the role of NS3 in HCV virion morphogenesis.IMPORTANCE HCV NS3 protein possesses the protease activity in its N-terminal domain and the helicase activity in its C-terminal domain. The role of NS3 in virus assembly has been mainly attributed to its helicase domain, because all adaptive mutations enhancing progeny virus production are found to be within this domain. Our study identified, for the first time to our knowledge, an adaptive mutation within the N-terminal helix α0 domain of NS3 that significantly enhanced virus assembly while having no effect on viral genome replication. The mechanistic studies suggested that this mutation promoted the relocation of core proteins from LD to the ER, leading to a more efficient envelopment of viral nucleocapsids. Our results revealed a possible new function of helix α0 in the HCV life cycle and provided new clues to understanding the molecular mechanisms for the action of NS3 in HCV assembly.
Collapse
|
23
|
Gerold G, Bruening J, Weigel B, Pietschmann T. Protein Interactions during the Flavivirus and Hepacivirus Life Cycle. Mol Cell Proteomics 2017; 16:S75-S91. [PMID: 28077444 DOI: 10.1074/mcp.r116.065649] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/11/2017] [Indexed: 12/28/2022] Open
Abstract
Protein-protein interactions govern biological functions in cells, in the extracellular milieu, and at the border between cells and extracellular space. Viruses are small intracellular parasites and thus rely on protein interactions to produce progeny inside host cells and to spread from cell to cell. Usage of host proteins by viruses can have severe consequences e.g. apoptosis, metabolic disequilibria, or altered cell proliferation and mobility. Understanding protein interactions during virus infection can thus educate us on viral infection and pathogenesis mechanisms. Moreover, it has led to important clinical translations, including the development of new therapeutic and vaccination strategies. Here, we will discuss protein interactions of members of the Flaviviridae family, which are small enveloped RNA viruses. Dengue virus, Zika virus and hepatitis C virus belong to the most prominent human pathogenic Flaviviridae With a genome of roughly ten kilobases encoding only ten viral proteins, Flaviviridae display intricate mechanisms to engage the host cell machinery for their purpose. In this review, we will highlight how dengue virus, hepatitis C virus, Japanese encephalitis virus, tick-borne encephalitis virus, West Nile virus, yellow fever virus, and Zika virus proteins engage host proteins and how this knowledge helps elucidate Flaviviridae infection. We will specifically address the protein composition of the virus particle as well as the protein interactions during virus entry, replication, particle assembly, and release from the host cell. Finally, we will give a perspective on future challenges in Flaviviridae interaction proteomics and why we believe these challenges should be met.
Collapse
Affiliation(s)
- Gisa Gerold
- From the Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany
| | - Janina Bruening
- From the Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany
| | - Bettina Weigel
- From the Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany
| | - Thomas Pietschmann
- From the Institute for Experimental Virology, TWINCORE, Centre for Experimental and Clinical Infection Research, a joint venture between the Medical School Hannover and the Helmholtz Centre for Infection Research, Hannover, Germany
| |
Collapse
|
24
|
Preclinical Characterization and Human Microdose Pharmacokinetics of ITMN-8187, a Nonmacrocyclic Inhibitor of the Hepatitis C Virus NS3 Protease. Antimicrob Agents Chemother 2016; 61:AAC.01569-16. [PMID: 27795376 DOI: 10.1128/aac.01569-16] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/09/2016] [Indexed: 12/11/2022] Open
Abstract
The current paradigm for the treatment of chronic hepatitis C virus (HCV) infection involves combinations of agents that act directly on steps of the HCV life cycle. Here we report the preclinical characteristics of ITMN-8187, a nonmacrocyclic inhibitor of the NS3/4A HCV protease. X-ray crystallographic studies of ITMN-8187 and simeprevir binding to NS3/4A protease demonstrated good agreement between structures. Low nanomolar biochemical potency was maintained against NS3/4A derived from HCV genotypes 1, 2b, 4, 5, and 6. In cell-based potency assays, half-maximal reduction of genotype 1a and 1b HCV replicon RNA was afforded by 11 and 4 nM doses of ITMN-8187, respectively. Combinations of ITMN-8187 with other directly acting antiviral agents in vitro displayed additive antiviral efficacy. A 30-mg/kg of body weight dose of ITMN-8187 administered for 4 days yielded significant viral load reductions through day 5 in a chimeric mouse model of HCV. A 3-mg/kg oral dose administered to rats, dogs, or monkeys yielded concentrations in plasma 16 h after dosing that exceeded the half-maximal effective concentration of ITMN-8187. Human microdose pharmacokinetics showed low intersubject variability and prolonged oral absorption with first-order elimination kinetics compatible with once-daily dosing. These preclinical characteristics compare favorably with those of other NS3/4A inhibitors approved for the treatment of chronic HCV infection.
Collapse
|
25
|
Tomei L, Altamura S, Paonessa G, De Francesco R, Migliaccio G. Review HCV Antiviral Resistance: The Impact of in vitro Studies on the Development of Antiviral Agents Targeting the Viral NS5B Polymerase. ACTA ACUST UNITED AC 2016; 16:225-45. [PMID: 16130521 DOI: 10.1177/095632020501600403] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The high prevalence of the disease caused by hepatitis C virus (HCV) and the limited efficacy of interferon-based therapies have stimulated the search for safer and more effective drugs. The development of inhibitors of the HCV NS5B RNA polymerase represents a promising strategy for identifying novel anti-HCV therapeutics. However, the high genetic diversity, mutation rate and turnover of HCV are expected to favour the emergence of drug resistance, limiting the clinical usefulness of polymerase inhibitors. Thus, the characterization of the drug-resistance profile of these antiviral agents is considered crucial for identifying the inhibitors with a higher probability of clinical success. In the absence of an efficient in vitro infection system, HCV sub-genomic replicons have been used to study viral resistance to both nucleoside and non-nucleoside NS5B inhibitors. While these studies suggest that drug-resistant viruses are likely to evolve in vivo, they provide a wealth of information that should help in the identification of inhibitors with improved and distinct resistance profiles that might be used for combination therapy.
Collapse
Affiliation(s)
- Licia Tomei
- Istituto di Ricerche di Biologia Molecolare P Angeletti, Pomezia-Roma, Italy
| | | | | | | | | |
Collapse
|
26
|
Roopngam P, Liu K, Mei L, Zheng Y, Zhu X, Tsai HI, Huang L. Hepatitis C virus E2 protein encapsulation into poly d, l-lactic- co-glycolide microspheres could induce mice cytotoxic T-cell response. Int J Nanomedicine 2016; 11:5361-5370. [PMID: 27789948 PMCID: PMC5072560 DOI: 10.2147/ijn.s109081] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Hepatitis C virus (HCV) is known to cause hepatitis and hepatocellular carcinoma. E2 envelope glycoprotein of HCV type (HCV-E2) has been reported to bind human host cells and is a major target for developing anti-HCV vaccines. However, the therapeutic vaccine for infected patients still needs further development. The vaccine aims to provide cytotoxic T-cells to eliminate infected cells and hepatocellular carcinoma. Currently, there is no effective HCV therapeutic vaccine because most chronically infected patients rarely generate cytotoxic T-cells, even though they have high levels of neutralizing antibodies. Therefore, the adjuvant must be applied to enhance the efficacy of the therapeutic vaccine. In this study, we constructed HCV1b-E2 recombinant protein, a truncated form of peptide, to combine with an effective vaccine adjuvant and delivery system by using poly d,l-lactic-co-glycolide (PLGA) microspheres. HCV1b-E2 protein was effectively encapsulated into PLGA microspheres (HCV1b-E2-PLGA) as a strategy to deliver an insoluble form of HCV1b-E2 protein. The size and shape of PLGA microspheres were generated properly to carry an insoluble form of viral peptide in vivo. The encapsulated viral protein was slowly and continuously released from PLGA microspheres, which indicated the property of the adjuvant. HCV1b-E2-PLGA can trigger a cell-mediated immune response by inducing an expression of mice CD8+ T-cells. Our results demonstrated that HCV1b-E2-PLGA-immunized mice have a significantly increased CD8+ T-cell number, whereas HCV1b-E2-immunized mice have a lower number of CD8+ T-cells. Moreover, HCV1b-E2-PLGA could induce a specific antibody to viral protein, and the immune cells could secrete IFN-γ, which is a significant cytokine for viral response. Thus, HCV1b-E2-PLGA is shown to have adjuvant property and efficacy in the murine model, which is a good strategy to develop HCV prophylactic and therapeutic vaccines.
Collapse
Affiliation(s)
- Piyachat Roopngam
- School of Life Sciences, Tsinghua University, Beijing, People's Republic of China; The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology and Biomedicine, State Key Laboratory of Health Sciences and Technology, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen, People's Republic of China
| | - Kewei Liu
- School of Life Sciences, Tsinghua University, Beijing, People's Republic of China; The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology and Biomedicine, State Key Laboratory of Health Sciences and Technology, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen, People's Republic of China
| | - Lin Mei
- The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology and Biomedicine, State Key Laboratory of Health Sciences and Technology, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen, People's Republic of China
| | - Yi Zheng
- The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology and Biomedicine, State Key Laboratory of Health Sciences and Technology, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen, People's Republic of China
| | - Xianbing Zhu
- School of Life Sciences, Tsinghua University, Beijing, People's Republic of China; The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology and Biomedicine, State Key Laboratory of Health Sciences and Technology, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen, People's Republic of China
| | - Hsiang-I Tsai
- School of Life Sciences, Tsinghua University, Beijing, People's Republic of China; The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology and Biomedicine, State Key Laboratory of Health Sciences and Technology, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen, People's Republic of China
| | - Laiqiang Huang
- School of Life Sciences, Tsinghua University, Beijing, People's Republic of China; The Shenzhen Key Laboratory of Gene and Antibody Therapy, Center for Biotechnology and Biomedicine, State Key Laboratory of Health Sciences and Technology, Division of Life and Health Sciences, Graduate School at Shenzhen, Tsinghua University, Shenzhen, People's Republic of China
| |
Collapse
|
27
|
Abstract
The recent approval by the regulatory authorities in the United States of several HIV proteinase inhibitors as therapeutics for the treatment of AIDS confirms that virus proteinases are valid molecular targets in the search for new antiviral drugs. This review summarizes the available approaches that can be taken to discover virus proteinase inhibitors and reviews the current status of our knowledge with respect to virus proteinases in viruses of clinical significance other than HIV. The major focus is on proteinases identified in the viruses that cause the common cold, hepatitis C virus and the herpesviruses.
Collapse
Affiliation(s)
- J. S. Mills
- Molecular Virology Department, Roche Research Centre, 40 Broadwater Road, Welwyn Garden City, Herts AL7 3AY, UK
| |
Collapse
|
28
|
Abstract
Hepatitis C virus (HCV) is the major cause of transfusion-associated hepatitis and accounts for a significant proportion of hepatitis cases worldwide. Most, if not all, infections become persistent and about 60% of cases develop chronic liver disease with various outcomes ranging from an asymptomatic carrier state to chronic active hepatitis and liver cirrhosis, which is strongly associated with the development of hepatocellular carcinoma. Since the initial cloning of the viral genome in 1989, our knowledge of the molecular biology of HCV has increased rapidly and led to the identification of several potential targets for antiviral intervention. In contrast, the low replication of the virus in cell culture, the lack of convenient animal models and the high genome variability present major challenges for drug development. This review will describe candidate drug targets and summarize ‘classical’ and ‘novel’ approaches currently being pursued to develop efficient HCV-specific therapies.
Collapse
Affiliation(s)
- R Bartenschlager
- Institute for Virology, Johannes-Gutenberg University of Mainz, Obere Zahlbacher Strasse 67, 55131 Mainz, Germany
| |
Collapse
|
29
|
Lee S, Yoon KD, Lee M, Cho Y, Choi G, Jang H, Kim B, Jung D, Oh J, Kim G, Oh J, Jeong Y, Kwon HJ, Bae SK, Min D, Windisch MP, Heo T, Lee C. Identification of a resveratrol tetramer as a potent inhibitor of hepatitis C virus helicase. Br J Pharmacol 2016; 173:191-211. [PMID: 26445091 PMCID: PMC4813382 DOI: 10.1111/bph.13358] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 09/16/2015] [Accepted: 10/02/2015] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND AND PURPOSE Hepatitis C virus (HCV) infection is responsible for various chronic inflammatory liver diseases. Here, we have identified a naturally occurring compound with anti-HCV activity and have elucidated its mode of antiviral action. EXPERIMENTAL APPROACH Luciferase reporter and real-time RT-PCR assays were used to measure HCV replication. Western blot, fluorescence-labelled HCV replicons and infectious clones were employed to quantitate expression levels of viral proteins. Resistant HCV mutant mapping, in vitro NS3 protease, helicase, NS5B polymerase and drug affinity responsive target stability assays were also used to study the antiviral mechanism. KEY RESULTS A resveratrol tetramer, vitisin B from grapevine root extract showed high potency against HCV replication (EC50 = 6 nM) with relatively low cytotoxicity (EC50 >10 μM). Combined treatment of vitisin B with an NS5B polymerase inhibitor (sofosbuvir) exhibited a synergistic or at least additive antiviral activity. Analysis of a number of vitisin B-resistant HCV variants suggested an NS3 helicase as its potential target. We confirmed a direct binding between vitisin B and a purified NS3 helicase in vitro. Vitisin B was a potent inhibitor of a HCV NS3 helicase (IC50 = 3 nM). In vivo, Finally, we observed a preferred tissue distribution of vitisin B in the liver after i.p. injection in rats, at clinically attainable concentrations. Conclusion and Implications Vitisin B is one of the most potent HCV helicase inhibitors identified so far. Vitisin B is thus a prime candidate to be developed as the first HCV drug derived from natural products.
Collapse
Affiliation(s)
- Sungjin Lee
- College of PharmacyDongguk UniversityGoyangKorea
| | - Kee Dong Yoon
- College of Pharmacy and Integrated Research Institute of Pharmaceutical SciencesThe Catholic University of KoreaBucheonKorea
| | - Myungeun Lee
- Hepatitis Research LaboratoryInstitut Pasteur KoreaSeongnamKorea
| | - Yoojin Cho
- Hepatitis Research LaboratoryInstitut Pasteur KoreaSeongnamKorea
| | - Gahee Choi
- Hepatitis Research LaboratoryInstitut Pasteur KoreaSeongnamKorea
| | - Hongje Jang
- Department of ChemistrySeoul National UniversitySeoulKorea
| | - BeomSeok Kim
- Translational Research Center for Protein Function Control, Department of Biotechnology, College of Life Science and BiotechnologyYonsei UniversitySeoulKorea
| | - Da‐Hee Jung
- Department of Bio and Nano ChemistryKookmin UniversitySeoulKorea
| | - Jin‐Gyo Oh
- College of Pharmacy and Integrated Research Institute of Pharmaceutical SciencesThe Catholic University of KoreaBucheonKorea
| | - Geon‐Woo Kim
- Department of BiotechnologyYonsei UniversitySeoulKorea
| | - Jong‐Won Oh
- Department of BiotechnologyYonsei UniversitySeoulKorea
| | - Yong‐Joo Jeong
- Department of Bio and Nano ChemistryKookmin UniversitySeoulKorea
| | - Ho Jeong Kwon
- Translational Research Center for Protein Function Control, Department of Biotechnology, College of Life Science and BiotechnologyYonsei UniversitySeoulKorea
| | - Soo Kyung Bae
- College of Pharmacy and Integrated Research Institute of Pharmaceutical SciencesThe Catholic University of KoreaBucheonKorea
| | - Dal‐Hee Min
- Department of ChemistrySeoul National UniversitySeoulKorea
| | - Marc P Windisch
- Hepatitis Research LaboratoryInstitut Pasteur KoreaSeongnamKorea
| | - Tae‐Hwe Heo
- College of Pharmacy and Integrated Research Institute of Pharmaceutical SciencesThe Catholic University of KoreaBucheonKorea
| | - Choongho Lee
- College of PharmacyDongguk UniversityGoyangKorea
| |
Collapse
|
30
|
Kumthip K, Maneekarn N. The role of HCV proteins on treatment outcomes. Virol J 2015; 12:217. [PMID: 26666318 PMCID: PMC4678629 DOI: 10.1186/s12985-015-0450-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/09/2015] [Indexed: 12/19/2022] Open
Abstract
For many years, the standard of treatment for hepatitis C virus (HCV) infection was a combination of pegylated interferon alpha (Peg-IFN-α) and ribavirin for 24–48 weeks. This treatment regimen results in a sustained virologic response (SVR) rate in about 50 % of cases. The failure of IFN-α-based therapy to eliminate HCV is a result of multiple factors including a suboptimal treatment regimen, severity of HCV-related diseases, host factors and viral factors. In recent years, advances in HCV cell culture have contributed to a better understanding of the viral life cycle, which has led to the development of a number of direct-acting antiviral agents (DAAs) that target specific key components of viral replication, such as HCV NS3/4A, HCV NS5A, and HCV NS5B proteins. To date, several new drugs have been approved for the treatment of HCV infection. Application of DAAs with IFN-based or IFN-free regimens has increased the SVR rate up to >90 % and has allowed treatment duration to be shortened to 12–24 weeks. The impact of HCV proteins in response to IFN-based and IFN-free therapies has been described in many reports. This review summarizes and updates knowledge on molecular mechanisms of HCV proteins involved in anti-IFN activity as well as examining amino acid variations and mutations in several regions of HCV proteins associated with the response to IFN-based therapy and pattern of resistance associated amino acid variants (RAV) to antiviral agents.
Collapse
Affiliation(s)
- Kattareeya Kumthip
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand.
| | - Niwat Maneekarn
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, 50200, Thailand.
| |
Collapse
|
31
|
Nawaz A, Zaidi SF, Usmanghani K, Ahmad I. Concise review on the insight of hepatitis C. J Taibah Univ Med Sci 2015. [DOI: 10.1016/j.jtumed.2014.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
32
|
Abstract
Pestiviruses are among the economically most important pathogens of livestock. The biology of these viruses is characterized by unique and interesting features that are both crucial for their success as pathogens and challenging from a scientific point of view. Elucidation of these features at the molecular level has made striking progress during recent years. The analyses revealed that major aspects of pestivirus biology show significant similarity to the biology of human hepatitis C virus (HCV). The detailed molecular analyses conducted for pestiviruses and HCV supported and complemented each other during the last three decades resulting in elucidation of the functions of viral proteins and RNA elements in replication and virus-host interaction. For pestiviruses, the analyses also helped to shed light on the molecular basis of persistent infection, a special strategy these viruses have evolved to be maintained within their host population. The results of these investigations are summarized in this chapter.
Collapse
Affiliation(s)
- Norbert Tautz
- Institute for Virology and Cell Biology, University of Lübeck, Lübeck, Germany
| | - Birke Andrea Tews
- Institut für Immunologie, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Gregor Meyers
- Institut für Immunologie, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany.
| |
Collapse
|
33
|
Isken O, Langerwisch U, Jirasko V, Rehders D, Redecke L, Ramanathan H, Lindenbach BD, Bartenschlager R, Tautz N. A conserved NS3 surface patch orchestrates NS2 protease stimulation, NS5A hyperphosphorylation and HCV genome replication. PLoS Pathog 2015; 11:e1004736. [PMID: 25774920 PMCID: PMC4361677 DOI: 10.1371/journal.ppat.1004736] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 02/06/2015] [Indexed: 12/22/2022] Open
Abstract
Hepatitis C virus (HCV) infection is a leading cause of liver disease worldwide. The HCV RNA genome is translated into a single polyprotein. Most of the cleavage sites in the non-structural (NS) polyprotein region are processed by the NS3/NS4A serine protease. The vital NS2-NS3 cleavage is catalyzed by the NS2 autoprotease. For efficient processing at the NS2/NS3 site, the NS2 cysteine protease depends on the NS3 serine protease domain. Despite its importance for the viral life cycle, the molecular details of the NS2 autoprotease activation by NS3 are poorly understood. Here, we report the identification of a conserved hydrophobic NS3 surface patch that is essential for NS2 protease activation. One residue within this surface region is also critical for RNA replication and NS5A hyperphosphorylation, two processes known to depend on functional replicase assembly. This dual function of the NS3 surface patch prompted us to reinvestigate the impact of the NS2-NS3 cleavage on NS5A hyperphosphorylation. Interestingly, NS2-NS3 cleavage turned out to be a prerequisite for NS5A hyperphosphorylation, indicating that this cleavage has to occur prior to replicase assembly. Based on our data, we propose a sequential cascade of molecular events: in uncleaved NS2-NS3, the hydrophobic NS3 surface patch promotes NS2 protease stimulation; upon NS2-NS3 cleavage, this surface region becomes available for functional replicase assembly. This model explains why efficient NS2-3 cleavage is pivotal for HCV RNA replication. According to our model, the hydrophobic surface patch on NS3 represents a module critically involved in the temporal coordination of HCV replicase assembly.
Collapse
Affiliation(s)
- Olaf Isken
- Institute of Virology and Cell Biology, University of Lübeck, Germany
| | | | - Vlastimil Jirasko
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Dirk Rehders
- Joint Laboratory for Structural Biology of Infection and Inflammation of the University of Hamburg and the University of Lübeck, DESY, Hamburg, Germany
| | - Lars Redecke
- Joint Laboratory for Structural Biology of Infection and Inflammation of the University of Hamburg and the University of Lübeck, DESY, Hamburg, Germany
| | - Harish Ramanathan
- Department of Microbial Pathogenesis, Yale University, New Haven, Connecticut, United States of America
| | - Brett D. Lindenbach
- Department of Microbial Pathogenesis, Yale University, New Haven, Connecticut, United States of America
| | - Ralf Bartenschlager
- Department of Molecular Virology, University of Heidelberg, Heidelberg, Germany
| | - Norbert Tautz
- Institute of Virology and Cell Biology, University of Lübeck, Germany
- * E-mail:
| |
Collapse
|
34
|
David N, Yaffe Y, Hagoel L, Elazar M, Glenn JS, Hirschberg K, Sklan EH. The interaction between the hepatitis C proteins NS4B and NS5A is involved in viral replication. Virology 2014; 475:139-49. [PMID: 25462354 DOI: 10.1016/j.virol.2014.10.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 08/07/2014] [Accepted: 10/22/2014] [Indexed: 02/07/2023]
Abstract
Hepatitis C virus (HCV) replicates in membrane associated, highly ordered replication complexes (RCs). These complexes include viral and host proteins necessary for viral RNA genome replication. The interaction network among viral and host proteins underlying the formation of these RCs is yet to be thoroughly characterized. Here, we investigated the association between NS4B and NS5A, two critical RC components. We characterized the interaction between these proteins using fluorescence resonance energy transfer and a mammalian two-hybrid system. Specific tryptophan residues within the C-terminal domain (CTD) of NS4B were shown to mediate this interaction. Domain I of NS5A, was sufficient to mediate its interaction with NS4B. Mutations in the NS4B CTD tryptophan residues abolished viral replication. Moreover, one of these mutations also affected NS5A hyperphosphorylation. These findings provide new insights into the importance of the NS4B-NS5A interaction and serve as a starting point for studying the complex interactions between the replicase subunits.
Collapse
Affiliation(s)
- Naama David
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Yakey Yaffe
- Department of Pathology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Lior Hagoel
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Menashe Elazar
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, United States
| | - Jeffrey S Glenn
- Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, United States; Veterans Administration Medical Center, Palo Alto, CA, United States
| | - Koret Hirschberg
- Department of Pathology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Ella H Sklan
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
| |
Collapse
|
35
|
Zhong M, Peng E, Huang N, Huang Q, Huq A, Lau M, Colonno R, Li L. Discovery of functionalized bisimidazoles bearing cyclic aliphatic-phenyl motifs as HCV NS5A inhibitors. Bioorg Med Chem Lett 2014; 24:5731-5737. [PMID: 25453810 DOI: 10.1016/j.bmcl.2014.10.057] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/11/2014] [Accepted: 10/17/2014] [Indexed: 02/06/2023]
Abstract
This Letter describes the discovery of a number of functionalized bisimidazoles bearing a cyclohexylphenyl, piperidylphenyl, or bicyclo[2,2,2]octylphenyl motif as HCV NS5A inhibitors. Compounds 2c, 4b and 6 have demonstrated low single-digit nM potency in gt-1a replicon and double-digit pM potency in gt-1b replicon, respectively. Moreover, both 4b and 6 have, respectively, exhibited good oral bioavailability in rats with a favorable liver/plasma ratio of the drug concentration.
Collapse
Affiliation(s)
- Min Zhong
- Presidio Pharmaceuticals, Inc., 1700 Owens Street, Suite 585, San Francisco, CA 94158, USA.
| | - Eric Peng
- Presidio Pharmaceuticals, Inc., 1700 Owens Street, Suite 585, San Francisco, CA 94158, USA
| | - Ningwu Huang
- Presidio Pharmaceuticals, Inc., 1700 Owens Street, Suite 585, San Francisco, CA 94158, USA
| | - Qi Huang
- Presidio Pharmaceuticals, Inc., 1700 Owens Street, Suite 585, San Francisco, CA 94158, USA
| | - Anja Huq
- Presidio Pharmaceuticals, Inc., 1700 Owens Street, Suite 585, San Francisco, CA 94158, USA
| | - Meiyen Lau
- Presidio Pharmaceuticals, Inc., 1700 Owens Street, Suite 585, San Francisco, CA 94158, USA
| | - Richard Colonno
- Presidio Pharmaceuticals, Inc., 1700 Owens Street, Suite 585, San Francisco, CA 94158, USA
| | - Leping Li
- Presidio Pharmaceuticals, Inc., 1700 Owens Street, Suite 585, San Francisco, CA 94158, USA.
| |
Collapse
|
36
|
Lee C. Interaction of hepatitis C virus core protein with janus kinase is required for efficient production of infectious viruses. Biomol Ther (Seoul) 2014; 21:97-106. [PMID: 24009866 PMCID: PMC3762308 DOI: 10.4062/biomolther.2013.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Revised: 02/22/2013] [Accepted: 02/27/2013] [Indexed: 01/22/2023] Open
Abstract
Chronic hepatitis C virus (HCV) infection is responsible for the development of liver cirrhosis and hepatocellular carcinoma. HCV core protein plays not only a structural role in the virion morphogenesis by encapsidating a virus RNA genome but also a non-structural role in HCV-induced pathogenesis by blocking innate immunity. Especially, it has been shown to regulate JAK-STAT signaling pathway through its direct interaction with Janus kinase (JAK) via its proline-rich JAK-binding motif (79PGYPWP84). However, little is known about the physiological significance of this HCV core-JAK association in the context of the virus life cycle. In order to gain an insight, a mutant HCV genome (J6/JFH1-79A82A) was constructed to express the mutant core with a defective JAK-binding motif (79AGYAWP84) using an HCV genotype 2a infectious clone (J6/JFH1). When this mutant HCV genome was introduced into hepatocarcinoma cells, it was found to be severely impaired in its ability to produce infectious viruses in spite of its robust RNA genome replication. Taken together, all these results suggest an essential requirement of HCV core-JAK protein interaction for efficient production of infectious viruses and the potential of using core-JAK blockers as a new anti-HCV therapy.
Collapse
Affiliation(s)
- Choongho Lee
- College of Pharmacy, Dongguk University-Seoul, Goyang 410-820, Republic of Korea
| |
Collapse
|
37
|
Sugiyama N, Murayama A, Suzuki R, Watanabe N, Shiina M, Liang TJ, Wakita T, Kato T. Single strain isolation method for cell culture-adapted hepatitis C virus by end-point dilution and infection. PLoS One 2014; 9:e98168. [PMID: 24848954 PMCID: PMC4029950 DOI: 10.1371/journal.pone.0098168] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 04/29/2014] [Indexed: 12/11/2022] Open
Abstract
The hepatitis C virus (HCV) culture system has enabled us to clarify the HCV life cycle and essential host factors for propagation. However, the virus production level of wild-type JFH-1 (JFH-1/wt) is limited, and this leads to difficulties in performing experiments that require higher viral concentrations. As the cell culture-adapted JFH-1 has been reported to have robust virus production, some mutations in the viral genome may play a role in the efficiency of virus production. In this study, we obtained cell culture-adapted virus by passage of full-length JFH-1 RNA-transfected Huh-7.5.1 cells. The obtained virus produced 3 log-fold more progeny viruses as compared with JFH-1/wt. Several mutations were identified as being responsible for robust virus production, but, on reverse-genetics analysis, the production levels of JFH-1 with these mutations did not reach the level of cell culture-adapted virus. By using the single strain isolation method by end-point dilution and infection, we isolated two strains with additional mutations, and found that these strains have the ability to produce more progeny viruses. On reverse-genetics analysis, the strains with these additional mutations were able to produce robust progeny viruses at comparable levels as cell culture-adapted JFH-1 virus. The strategy used in this study will be useful for identifying strains with unique characteristics, such as robust virus production, from a diverse population, and for determining the responsible mutations for these characteristics.
Collapse
Affiliation(s)
- Nao Sugiyama
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Asako Murayama
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Ryosuke Suzuki
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Noriyuki Watanabe
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Masaaki Shiina
- Department of Gastroenterology and Hepatology, Shin-Yurigaoka General Hospital, Kawasaki, Kanagawa, Japan
| | - T. Jake Liang
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Takaji Wakita
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takanobu Kato
- Department of Virology II, National Institute of Infectious Diseases, Tokyo, Japan
- * E-mail:
| |
Collapse
|
38
|
Fan X, Xue B, Dolan PT, LaCount DJ, Kurgan L, Uversky VN. The intrinsic disorder status of the human hepatitis C virus proteome. MOLECULAR BIOSYSTEMS 2014; 10:1345-63. [PMID: 24752801 DOI: 10.1039/c4mb00027g] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Many viral proteins or their biologically important regions are disordered as a whole, or contain long disordered regions. These intrinsically disordered proteins/regions do not possess unique structures and possess functions that complement the functional repertoire of "normal" ordered proteins and domains, with many protein functional classes being heavily dependent on the intrinsic disorder. Viruses commonly use these highly flexible regions to invade the host organisms and to hijack various host systems. These disordered regions also help viruses in adapting to their hostile habitats and to manage their economic usage of genetic material. In this article, we focus on the structural peculiarities of proteins from human hepatitis C virus (HCV) and use a wide spectrum of bioinformatics techniques to evaluate the abundance of intrinsic disorder in the completed proteomes of several human HCV genotypes, to analyze the peculiarities of disorder distribution within the individual HCV proteins, and to establish potential roles of the structural disorder in functions of ten HCV proteins. We show that the intrinsic disorder or increased flexibility is not only abundant in these proteins, but is also absolutely necessary for their functions, playing a crucial role in the proteolytic processing of the HCV polyprotein, the maturation of the individual HCV proteins, and being related to the posttranslational modifications of these proteins and their interactions with DNA, RNA, and various host proteins.
Collapse
Affiliation(s)
- Xiao Fan
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta AB T6G 2V4, Canada.
| | | | | | | | | | | |
Collapse
|
39
|
NS2 proteins of GB virus B and hepatitis C virus share common protease activities and membrane topologies. J Virol 2014; 88:7426-44. [PMID: 24741107 DOI: 10.1128/jvi.00656-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
UNLABELLED GB virus B (GBV-B), which is hepatotropic in experimentally infected small New World primates, is a member of the Hepacivirus genus but phylogenetically relatively distant from hepatitis C virus (HCV). To gain insights into the role and specificity of hepaciviral nonstructural protein 2 (NS2), which is required for HCV polyprotein processing and particle morphogenesis, we investigated whether NS2 structural and functional features are conserved between HCV and GBV-B. We found that GBV-B NS2, like HCV NS2, has cysteine protease activity responsible for cleavage at the NS2/NS3 junction, and we experimentally confirmed the location of this junction within the viral polyprotein. A model for GBV-B NS2 membrane topology was experimentally established by determining the membrane association properties of NS2 segments fused to green fluorescent protein (GFP) and their nuclear magnetic resonance structures using synthetic peptides as well as by applying an N-glycosylation scanning approach. Similar glycosylation studies confirmed the HCV NS2 organization. Together, our data show that despite limited amino acid sequence similarity, GBV-B and HCV NS2 proteins share a membrane topology with 3 N-terminal transmembrane segments, which is also predicted to apply to other recently discovered hepaciviruses. Based on these data and using trans-complementation systems, we found that intragenotypic hybrid NS2 proteins with heterologous N-terminal membrane segments were able to efficiently trans-complement an assembly-deficient HCV mutant with a point mutation in the NS2 C-terminal domain, while GBV-B/HCV or intergenotypic NS2 chimeras were not. These studies indicate that virus- and genotype-specific intramolecular interactions between N- and C-terminal domains of NS2 are critically involved in HCV morphogenesis. IMPORTANCE Nonstructural protein 2 (NS2) of hepatitis C virus (HCV) is a multifunctional protein critically involved in polyprotein processing and virion morphogenesis. To gain insights into NS2 mechanisms of action, we investigated whether NS2 structural and functional features are conserved between HCV and GB virus B (GBV-B), a phylogenetically relatively distant primate hepacivirus. We showed that GBV-B NS2, like HCV NS2, carries cysteine protease activity. We experimentally established a model for GBV-B NS2 membrane topology and demonstrated that despite limited sequence similarity, GBV-B and HCV NS2 share an organization with three N-terminal transmembrane segments. We found that the role of HCV NS2 in particle assembly is genotype specific and relies on critical interactions between its N- and C-terminal domains. This first comparative analysis of NS2 proteins from two hepaciviruses and our structural predictions of NS2 from other newly identified mammal hepaciviruses highlight conserved key features of the hepaciviral life cycle.
Collapse
|
40
|
In vitro selection of the 3′-untranslated regions of the human liver mRNA that bind to the HCV nonstructural protein 5B. Virology 2014; 450-451:13-23. [DOI: 10.1016/j.virol.2013.11.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 11/12/2013] [Accepted: 11/21/2013] [Indexed: 12/21/2022]
|
41
|
Jin G, Lee S, Choi M, Son S, Kim GW, Oh JW, Lee C, Lee K. Chemical genetics-based discovery of indole derivatives as HCV NS5B polymerase inhibitors. Eur J Med Chem 2014; 75:413-25. [PMID: 24561671 DOI: 10.1016/j.ejmech.2014.01.062] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 01/24/2014] [Accepted: 01/30/2014] [Indexed: 11/16/2022]
Abstract
In order to identify the inhibitors of hepatitis C virus (HCV) replication with a novel scaffold via a mechanistically unbiased approach, we screened our in-house library composed of ∼6000 compounds with various chemical structures by using the renilla luciferase-linked genotype 2a reporter virus, and we identified a series of compounds containing an indole moiety that were active against HCV replication. Based on this result, we further synthesized three groups of indole derivatives and evaluated their inhibitory effects on HCV replication. In the present structure-activity relationship study of these indole derivatives, we discovered that compound 12e was the most potent inhibitor of HCV replication with minimal cytotoxicity (EC50 = 1.1 μM, EC90 = 2.1 μM, and CC50 = 61.8 μM). We also confirmed that compound 12e caused a dose- and time-dependent reduction of viral RNA as well as viral protein levels in both genotype 2a J6/JFH1 RNA-transfected cells and genotype 1b Bart79I subgenomic replicon cells. Finally, a genetic mapping study of mutant viruses resistant to compound 12e revealed that NS5B RNA polymerase was the potential target. This finding was further validated by demonstration of inhibition of NS5B RNA polymerase in vitro by compound 12e (IC50 = 292 nM). Compound 12e may serve as a valuable candidate for the development of a new class of HCV NS5B RNA polymerase inhibitors in the future.
Collapse
Affiliation(s)
- Guanghai Jin
- College of Pharmacy, Dongguk University-Seoul, 410-820 Goyang, Republic of Korea
| | - Sungjin Lee
- College of Pharmacy, Dongguk University-Seoul, 410-820 Goyang, Republic of Korea
| | - Moonju Choi
- College of Pharmacy, Dongguk University-Seoul, 410-820 Goyang, Republic of Korea
| | - Seohyun Son
- College of Pharmacy, Dongguk University-Seoul, 410-820 Goyang, Republic of Korea
| | - Geon-Woo Kim
- Department of Biotechnology and Translational Research Center for Protein Function Control, Yonsei University, 120-749 Seoul, Republic of Korea
| | - Jong-Won Oh
- Department of Biotechnology and Translational Research Center for Protein Function Control, Yonsei University, 120-749 Seoul, Republic of Korea
| | - Choongho Lee
- College of Pharmacy, Dongguk University-Seoul, 410-820 Goyang, Republic of Korea.
| | - Kyeong Lee
- College of Pharmacy, Dongguk University-Seoul, 410-820 Goyang, Republic of Korea.
| |
Collapse
|
42
|
Abstract
Chronic hepatitis C virus (HCV) infection is responsible for the development of liver cirrhosis and hepatocellular carcinoma. It has been a tremendous burden on global health care systems. With the advent of a number of new direct-acting and host-targeting antiviral agents, current interferon-α- and ribavirin-based HCV therapy has started to move towards an interferon-sparing or even interferon-free strategy. In this regard, a recently identified NS5A inhibitor, daclatasvir, showed a great promise in clinical trials as another new class of direct-acting anti-HCV therapeutics, with a distinct mechanism of action. In this review, a variety of preclinical as well as clinical proof-of-concept studies of daclatasvir, including the studies of its discovery, mechanism of action, viral resistance, and host polymorphism profiles are reviewed. In addition, a role of daclatasvir in the future therapy for HCV patients is discussed briefly.
Collapse
Affiliation(s)
- Choongho Lee
- College of Pharmacy, Dongguk University-Seoul, Goyang, Republic of Korea
| |
Collapse
|
43
|
Abstract
Hepatitis C Virus (HCV) particles exhibit several unusual properties that are not found in other enveloped RNA viruses, most notably their low buoyant density and interaction with serum lipoproteins. With the advent of systems to grow HCV in cell culture, the molecular basis of HCV particle assembly and release can now be addressed. The process of virus assembly involves protein-protein interactions between viral structural and nonstructural proteins and the coordinated action of host factors. This chapter reviews our current understanding of these interactions and factors.
Collapse
Affiliation(s)
- Brett D Lindenbach
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, CT 06536, USA.
| |
Collapse
|
44
|
Choi M, Lee S, Choi T, Lee C. A hepatitis C virus NS4B inhibitor suppresses viral genome replication by disrupting NS4B's dimerization/multimerization as well as its interaction with NS5A. Virus Genes 2013; 47:395-407. [PMID: 23868571 DOI: 10.1007/s11262-013-0956-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 07/08/2013] [Indexed: 01/14/2023]
Abstract
Chronic hepatitis C virus (HCV) infection is responsible for severe liver diseases including liver cirrhosis and hepatocellular carcinoma. An HCV non-structural protein 4B (NS4B) plays an essential role in viral RNA genome replication by building multi-vesicular structures around endoplasmic reticulum membranes. Especially, the second amphipathic helix of NS4B (NS4B-AH2) was shown to be essential for this process. By screening compounds against a membrane-aggregating activity of NS4B-AH2, several anti-HCV replication small molecules targeting NS4B-AH2 were discovered. However, little is known about detailed molecular mechanism of action for these NS4B-AH2 inhibitors. In this report, we provide evidences that NS4B-AH2 is required for NS4B's dimerization/multimerization, its proper subcellular localization, as well as its interaction with NS5A. More importantly, one of NS4B-AH2 inhibitors called "anguizole" was found to be able to disrupt all of these NS4B-AH2-mediated biological functions of NS4B. This newly elucidated mechanism of action will enable us not only to better understand a central role of NS4B-AH2 in HCV life cycle but also to develop a more safe and effective new class of NS4B-AH2 inhibitors of HCV replication in the future.
Collapse
Affiliation(s)
- Moonju Choi
- College of Pharmacy, Dongguk University-Seoul, Goyang, 410-050, South Korea
| | | | | | | |
Collapse
|
45
|
Vega S, Neira JL, Marcuello C, Lostao A, Abian O, Velazquez-Campoy A. NS3 protease from hepatitis C virus: biophysical studies on an intrinsically disordered protein domain. Int J Mol Sci 2013; 14:13282-306. [PMID: 23803659 PMCID: PMC3742187 DOI: 10.3390/ijms140713282] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 06/04/2013] [Accepted: 06/13/2013] [Indexed: 12/14/2022] Open
Abstract
The nonstructural protein 3 (NS3) from the hepatitis C virus (HCV) is responsible for processing the non-structural region of the viral precursor polyprotein in infected hepatic cells. NS3 protease activity, located at the N-terminal domain, is a zinc-dependent serine protease. A zinc ion, required for the hydrolytic activity, has been considered as a structural metal ion essential for the structural integrity of the protein. In addition, NS3 interacts with another cofactor, NS4A, an accessory viral protein that induces a conformational change enhancing the hydrolytic activity. Biophysical studies on the isolated protease domain, whose behavior is similar to that of the full-length protein (e.g., catalytic activity, allosteric mechanism and susceptibility to inhibitors), suggest that a considerable global conformational change in the protein is coupled to zinc binding. Zinc binding to NS3 protease can be considered as a folding event, an extreme case of induced-fit binding. Therefore, NS3 protease is an intrinsically (partially) disordered protein with a complex conformational landscape due to its inherent plasticity and to the interaction with its different effectors. Here we summarize the results from a detailed biophysical characterization of this enzyme and present new experimental data.
Collapse
Affiliation(s)
- Sonia Vega
- Institute of Biocomputation and Physics of Complex Systems (BIFI), Joint Unit BIFI-IQFR (CSIC), University of Zaragoza, Zaragoza 50018, Spain; E-Mails: (S.V.); (J.L.N.)
| | - Jose L. Neira
- Institute of Biocomputation and Physics of Complex Systems (BIFI), Joint Unit BIFI-IQFR (CSIC), University of Zaragoza, Zaragoza 50018, Spain; E-Mails: (S.V.); (J.L.N.)
- Institute of Molecular and Cell Biology, Miguel Hernandez University, Elche (Alicante) 03202, Spain
| | - Carlos Marcuello
- Advanced Microscopy Laboratory (LMA), Institute of Nanoscience of Aragon (INA), University of Zaragoza, Zaragoza 50018, Spain; E-Mails: (C.M.); (A.L.)
| | - Anabel Lostao
- Advanced Microscopy Laboratory (LMA), Institute of Nanoscience of Aragon (INA), University of Zaragoza, Zaragoza 50018, Spain; E-Mails: (C.M.); (A.L.)
- ARAID Foundation, Government of Aragon, Zaragoza 50018, Spain
| | - Olga Abian
- Institute of Biocomputation and Physics of Complex Systems (BIFI), Joint Unit BIFI-IQFR (CSIC), University of Zaragoza, Zaragoza 50018, Spain; E-Mails: (S.V.); (J.L.N.)
- IIS Aragon–Aragon Health Science Institute (I+CS), Zaragoza 50009, Spain
- Network Biomedical Research Center on Hepatic and Digestive Diseases (CIBERehd), Barcelona 08036, Spain
- Authors to whom correspondence should be addressed; E-Mails: (O.A.); (A.V.-C.); Tel.: +34-976-761-000 (ext. 5417) (O.A.); +34-976-762-996 (A.V.-C.); Fax: +34-976-762-990 (O.A. & A.V.-C.)
| | - Adrian Velazquez-Campoy
- Institute of Biocomputation and Physics of Complex Systems (BIFI), Joint Unit BIFI-IQFR (CSIC), University of Zaragoza, Zaragoza 50018, Spain; E-Mails: (S.V.); (J.L.N.)
- ARAID Foundation, Government of Aragon, Zaragoza 50018, Spain
- Department of Biochemistry and Cellular and Molecular Biology, Faculty of Sciences, University of Zaragoza, Zaragoza 50009, Spain
- Authors to whom correspondence should be addressed; E-Mails: (O.A.); (A.V.-C.); Tel.: +34-976-761-000 (ext. 5417) (O.A.); +34-976-762-996 (A.V.-C.); Fax: +34-976-762-990 (O.A. & A.V.-C.)
| |
Collapse
|
46
|
Lopez OD, Nguyen VN, St. Laurent DR, Belema M, Serrano-Wu MH, Goodrich JT, Yang F, Qiu Y, Ripka AS, Nower PT, Valera L, Liu M, O’Boyle DR, Sun JH, Fridell RA, Lemm JA, Gao M, Good AC, Meanwell NA, Snyder LB. HCV NS5A replication complex inhibitors. Part 3: discovery of potent analogs with distinct core topologies. Bioorg Med Chem Lett 2013; 23:779-84. [DOI: 10.1016/j.bmcl.2012.11.086] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 11/14/2012] [Accepted: 11/20/2012] [Indexed: 12/23/2022]
|
47
|
|
48
|
Lee C. Roles of phosphoinositides and phosphoinositides kinases in hepatitis C virus RNA replication. Arch Pharm Res 2012; 35:1701-11. [PMID: 23139120 DOI: 10.1007/s12272-012-1001-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Accepted: 08/09/2012] [Indexed: 12/18/2022]
Abstract
Phosphoinositides (PIs) play an essential role in mediating key signaling pathways on biological membranes. Hepatitis C virus (HCV) replicates its RNA genome by establishing a viral replication complex (RC) on host cell membranes. Recently, an increasing body of literature reported that not only PIs themselves but also several PIs-specific kinases are required for efficient replication of HCV RNA genome. Especially, PI 4-kinases type III alpha, beta as well as their enzymatic products including phosphatidylinositol 4-phosphate (PI(4)P) and phosphatidylinositol 4,5-bisphosphate (PI(4,5)P(2)) are consistently identified to be host factors essential for HCV replication. In this article, the current state of our knowledge of PIs and PIs-specific kinases together with their roles in modulating HCV replication is reviewed. The effects of various PIs-specific kinases inhibitors on HCV replication are also highlighted, proposing them as promising candidate targets to which a new class of anti-HCV therapeutics can be envisaged.
Collapse
Affiliation(s)
- Choongho Lee
- Dongguk University College of Pharmacy, Goyang, Korea.
| |
Collapse
|
49
|
Different mechanisms of hepatitis C virus RNA polymerase activation by cyclophilin A and B in vitro. Biochim Biophys Acta Gen Subj 2012; 1820:1886-92. [PMID: 22954804 DOI: 10.1016/j.bbagen.2012.08.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 07/25/2012] [Accepted: 08/21/2012] [Indexed: 01/27/2023]
Abstract
BACKGROUND Cyclophilins (CyPs) are cellular proteins that are essential to hepatitis C virus (HCV) replication. Since cyclosporine A was discovered to inhibit HCV infection, the CyP pathway contributing to HCV replication is a potential attractive stratagem for controlling HCV infection. Among them, CyPA is accepted to interact with HCV nonstructural protein (NS) 5A, although interaction of CyPB and NS5B, an RNA-dependent RNA polymerase (RdRp), was proposed first. METHODS CyPA, CyPB, and HCV RdRp were expressed in bacteria and purified using combination column chromatography. HCV RdRp activity was analyzed in vitro with purified CyPA and CyPB. RESULTS CyPA at a high concentration (50× higher than that of RdRp) but not at low concentration activated HCV RdRp. CyPB had an allosteric effect on genotype 1b RdRp activation. CyPB showed genotype specificity and activated genotype 1b and J6CF (2a) RdRps but not genotype 1a or JFH1 (2a) RdRps. CyPA activated RdRps of genotypes 1a, 1b, and 2a. CyPB may also support HCV genotype 1b replication within the infected cells, although its knockdown effect on HCV 1b replicon activity was controversial in earlier reports. CONCLUSIONS CyPA activated HCV RdRp at the early stages of transcription, including template RNA binding. CyPB also activated genotype 1b RdRp. However, their activation mechanisms are different. GENERAL SIGNIFICANCE These data suggest that both CyPA and CyPB are excellent targets for the treatment of HCV 1b, which shows the greatest resistance to interferon and ribavirin combination therapy.
Collapse
|
50
|
Effect on hepatitis C virus replication of combinations of direct-acting antivirals, including NS5A inhibitor daclatasvir. Antimicrob Agents Chemother 2012; 56:5230-9. [PMID: 22850513 DOI: 10.1128/aac.01209-12] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Three hepatitis C virus (HCV) inhibitors, asunaprevir (ASV; BMS-650032), daclatasvir (DCV; BMS-790052), and BMS-791325, each targeting a different nonstructural protein of the virus (NS3, NS5A, and NS5B, respectively), have independently demonstrated encouraging preclinical profiles and are currently undergoing clinical evaluation. Since drug-resistant variants have rapidly developed in response to monotherapy with almost all direct-acting antiviral agents (DAAs) for HCV, the need for combination therapies to effectively eradicate the virus from infected patients is clear. These studies demonstrated the additive-synergistic effects on replicon inhibition and clearance of combining NS3 protease or NS5B RNA polymerase inhibitors with the first-in-class, NS5A replication complex inhibitor daclatasvir (DCV) and reveal new resistance pathways for combinations of two small-molecule inhibitors that differ from those that develop during monotherapy. The results suggest that under a specific selective pressure, a balance must be reached in the fitness costs of substitutions in one target gene when substitutions are also present in another target gene. Further synergies and additional novel resistance substitutions were observed during triple-combination treatment relative to dual-drug therapy, indicating that, in combination, HCV inhibitors can exert cross-target influences on resistance development. Enhanced synergies in replicon inhibition and a reduced frequency of resistance together lend strong support to the utility of combinations of DAAs for the treatment of HCV, and the identification of altered resistance profiles during combination treatment provides useful information for monitoring resistance in the clinic.
Collapse
|