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Sherwood AV, Rivera-Rangel LR, Ryberg LA, Larsen HS, Anker KM, Costa R, Vågbø CB, Jakljevič E, Pham LV, Fernandez-Antunez C, Indrisiunaite G, Podolska-Charlery A, Grothen JER, Langvad NW, Fossat N, Offersgaard A, Al-Chaer A, Nielsen L, Kuśnierczyk A, Sølund C, Weis N, Gottwein JM, Holmbeck K, Bottaro S, Ramirez S, Bukh J, Scheel TKH, Vinther J. Hepatitis C virus RNA is 5'-capped with flavin adenine dinucleotide. Nature 2023:10.1038/s41586-023-06301-3. [PMID: 37407817 DOI: 10.1038/s41586-023-06301-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 06/08/2023] [Indexed: 07/07/2023]
Abstract
RNA viruses have evolved elaborate strategies to protect their genomes, including 5' capping. However, until now no RNA 5' cap has been identified for hepatitis C virus1,2 (HCV), which causes chronic infection, liver cirrhosis and cancer3. Here we demonstrate that the cellular metabolite flavin adenine dinucleotide (FAD) is used as a non-canonical initiating nucleotide by the viral RNA-dependent RNA polymerase, resulting in a 5'-FAD cap on the HCV RNA. The HCV FAD-capping frequency is around 75%, which is the highest observed for any RNA metabolite cap across all kingdoms of life4-8. FAD capping is conserved among HCV isolates for the replication-intermediate negative strand and partially for the positive strand. It is also observed in vivo on HCV RNA isolated from patient samples and from the liver and serum of a human liver chimeric mouse model. Furthermore, we show that 5'-FAD capping protects RNA from RIG-I mediated innate immune recognition but does not stabilize the HCV RNA. These results establish capping with cellular metabolites as a novel viral RNA-capping strategy, which could be used by other viruses and affect anti-viral treatment outcomes and persistence of infection.
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Affiliation(s)
- Anna V Sherwood
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Lizandro R Rivera-Rangel
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Line A Ryberg
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Helena S Larsen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Klara M Anker
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Rui Costa
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Cathrine B Vågbø
- Proteomics and Modomics Experimental Core (PROMEC), Norwegian University of Science and Technology and the Central Norway Regional Health Authority, Trondheim, Norway
| | - Eva Jakljevič
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Long V Pham
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Carlota Fernandez-Antunez
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Gabriele Indrisiunaite
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Agnieszka Podolska-Charlery
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Julius E R Grothen
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Nicklas W Langvad
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Nicolas Fossat
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Anna Offersgaard
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Amal Al-Chaer
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Louise Nielsen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Anna Kuśnierczyk
- Proteomics and Modomics Experimental Core (PROMEC), Norwegian University of Science and Technology and the Central Norway Regional Health Authority, Trondheim, Norway
| | - Christina Sølund
- Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen N, Denmark
| | - Nina Weis
- Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen N, Denmark
| | - Judith M Gottwein
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Kenn Holmbeck
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Sandro Bottaro
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen N, Denmark
| | - Santseharay Ramirez
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark.
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark.
| | - Troels K H Scheel
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark.
- Copenhagen Hepatitis C Program (CO-HEP), Department of Immunology and Microbiology, University of Copenhagen, Copenhagen N, Denmark.
- Laboratory of Virology and Infectious Disease, The Rockefeller University, New York, NY, USA.
| | - Jeppe Vinther
- Section for Computational and RNA Biology, Department of Biology, University of Copenhagen, Copenhagen N, Denmark.
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Mei X, Zou J, Shi B, Qian Z, Yi Z. High-Resolution Genomic Profiling of a Genotype 3b Hepatitis C Virus from a Flare of an Occult Hepatitis Patient with Acute-on-Chronic Liver Failure. Viruses 2023; 15:v15030634. [PMID: 36992343 PMCID: PMC10059314 DOI: 10.3390/v15030634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 03/03/2023] Open
Abstract
Acute-on-chronic liver failure (ACLF) is defined as a syndrome of acutely decompensated cirrhosis in patients with chronic liver disease (CLD). Here we report an ACLF case caused by a flare of occult hepatitis C infection. This patient was infected with hepatitis C virus (HCV) more than a decade ago and hospitalized due to alcohol-associated CLD. Upon admission, the HCV RNA in the serum was negative and the anti-HCV antibody was positive, whereas the viral RNA in the plasma dramatically increased during hospitalization, which suggests an occult hepatitis C infection. Overlapped fragments encompassing the nearly whole HCV viral genome were amplified, cloned, and sequenced. Phylogenetic analysis indicated an HCV genotype 3b strain. Sanger sequencing to 10-fold coverage of the 9.4-kb nearly whole genome reveals high diversity of viral quasispecies, an indicator of chronic infection. Inherent resistance-associated substitutions (RASs) in the NS3 and NS5A but not in the NS5B regions were identified. The patient developed liver failure and accepted liver transplantation, followed by direct-acting antiviral (DAA) treatment. The hepatitis C was cured by the DAA treatment despite the existence of RASs. Thus, care should be taken for occult hepatitis C in patients with alcoholic cirrhosis. The analysis of viral genetic diversity may help to identify an occult hepatitis C virus infection and predict the efficacy of anti-viral treatment.
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Affiliation(s)
- Xue Mei
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Jingyi Zou
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai 200032, China
| | - Bisheng Shi
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Zhiping Qian
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
| | - Zhigang Yi
- Shanghai Public Health Clinical Center, Fudan University, Shanghai 201508, China
- Key Laboratory of Medical Molecular Virology (MOE/NHC/CAMS), School of Basic Medical Sciences, Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai 200032, China
- Correspondence:
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3
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A Novel Small Molecule Inhibits Hepatitis C Virus Propagation in Cell Culture. Microbiol Spectr 2021; 9:e0043921. [PMID: 34319169 PMCID: PMC8552720 DOI: 10.1128/spectrum.00439-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Hepatitis C virus (HCV) can cause acute and chronic infection that is associated with considerable liver-related morbidity and mortality. In recent years, there has been a shift in the treatment paradigm with the discovery and approval of agents that target specific proteins vital for viral replication. We employed a cell culture-adapted strain of HCV and human hepatoma-derived cells lines to test the effects of our novel small-molecule compound (AO13) on HCV. Virus inhibition was tested by analyzing RNA replication, protein expression, and virus production in virus-infected cells treated with AO13. Treatment with AO13 inhibited virus spread in cell culture and showed a 100-fold reduction in the levels of infectious virus production. AO13 significantly reduced the level of viral RNA contained within cell culture fluids and reduced the cellular levels of HCV core protein, suggesting that the compound might act on a late step in the viral life cycle. Finally, we observed that AO13 did not affect the release of infectious virus from infected cells. Docking studies and molecular dynamics analyses suggested that AO13 might target the NS5B RNA polymerase, however, real-time RT-PCR analyses of cellular levels of HCV RNA showed only an ∼2-fold reduction in viral RNA levels in the presence of AO13. Taken together, this study revealed that AO13 showed consistent, but low-level antiviral effect against HCV, although the mechanism of action remains unclear. IMPORTANCE The discovery of curative antiviral drugs for a chronic disease such as HCV infection has encouraged drug discovery in the context of other viruses for which no curative drugs currently exist. Since we currently face a novel virus that has caused a pandemic, the need for new antiviral agents is more apparent than ever. We describe here a novel compound that shows a modest antiviral effect against HCV that could serve as a lead compound for future drug development against other important viruses such as SARS-CoV-2.
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4
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Major M, Gutfraind A, Shekhtman L, Cui Q, Kachko A, Cotler SJ, Hajarizadeh B, Sacks-Davis R, Page K, Boodram B, Dahari H. Modeling of patient virus titers suggests that availability of a vaccine could reduce hepatitis C virus transmission among injecting drug users. Sci Transl Med 2019; 10:10/449/eaao4496. [PMID: 29997251 DOI: 10.1126/scitranslmed.aao4496] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 02/24/2018] [Accepted: 06/22/2018] [Indexed: 12/15/2022]
Abstract
The major route of hepatitis C virus (HCV) transmission in the United States is injection drug use. We hypothesized that if an HCV vaccine were available, vaccination could affect HCV transmission among people who inject drugs by reducing HCV titers after viral exposure without necessarily achieving sterilizing immunity. To investigate this possibility, we developed a mathematical model to determine transmission probabilities relative to the HCV RNA titers of needle/syringe-sharing donors. We simulated sharing of two types of syringes fitted with needles that retain either large or small amounts of fluid after expulsion. Using previously published viral kinetics data from both naïve subjects infected with HCV and reinfected individuals who had previously cleared an HCV infection, we estimated transmission risk between pairs of serodiscordant injecting drug users, accounting for syringe type, rinsing, and sharing frequency. We calculated that the risk of HCV transmission through syringe sharing increased ~10-fold as viral titers (log10 IU/ml) increased ~25-fold. Cumulative analyses showed that, assuming sharing episodes every 7 days, the mean transmission risk over the first 6 months was >90% between two people sharing syringes when one had an HCV RNA titer >5 log10 IU/ml. For those with preexisting immunity that rapidly controlled HCV, the cumulative risk decreased to 1 to 25% depending on HCV titer and syringe type. Our modeling approach demonstrates that, even with transient viral replication after exposure during injection drug use, HCV transmission among people sharing syringes could be reduced through vaccination if an HCV vaccine were available.
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Affiliation(s)
- Marian Major
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA.
| | - Alexander Gutfraind
- Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.,Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Louis Shekhtman
- Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.,Department of Physics, Bar-Ilan University, Ramat Gan 52990, Israel
| | - Qingwen Cui
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Alla Kachko
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Scott J Cotler
- Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Chicago, Maywood, IL 60153, USA
| | - Behzad Hajarizadeh
- The Kirby Institute, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Rachel Sacks-Davis
- Disease Elimination Program, Burnet Institute, Melbourne, Victoria 3004, Australia.,Department of Medicine, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Kimberly Page
- Division of Epidemiology, Biostatistics and Preventive Medicine, Department of Internal Medicine, University of New Mexico Health Sciences Center, Albuquerque, NM 87131, USA
| | - Basmattee Boodram
- Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Harel Dahari
- Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Chicago, Maywood, IL 60153, USA.
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5
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Modeling suggests that microliter volumes of contaminated blood caused an outbreak of hepatitis C during computerized tomography. PLoS One 2019; 14:e0210173. [PMID: 30645600 PMCID: PMC6333404 DOI: 10.1371/journal.pone.0210173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 12/18/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND & AIMS Acute hepatitis C (AHC) is not frequently identified because patients are usually asymptomatic, although may be recognized after iatrogenic exposures such as needle stick injuries, medical injection, and acupuncture. We describe an outbreak of AHC among 12 patients who received IV saline flush from a single multi-dose vial after intravenous contrast administration for a computerized tomography (CT) scan. The last patient to receive IV contrast with saline flush from a multi-dose vial at the clinic on the previous day was known to have chronic HCV genotype 1b (termed potential source, PS). Here we sought to confirm (via genetic analysis) the source of infection and to predict the minimal contaminating level of IV saline flush needed to transmit infectious virus to all patients. METHODS In order to confirm the source of infection, we sequenced the HCV E1E2 region in 7 CT patients, in PS, and in 2 control samples from unrelated patients also infected with HCV genotype 1b. A transmission probabilistic model was developed to predict the contamination volume of blood that would have been sufficient to transmit infectious virus to all patients. RESULTS Viral sequencing showed close clustering of the cases with the PS. The transmission probabilistic model predicted that contamination of the multi-dose saline vial with 0.6-8.7 microliters of blood would have been sufficient to transmit infectious virus to all patients. CONCLUSION Analysis of this unique cohort provides a new understanding of HCV transmission with respect to contaminating volumes and viral titers.
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6
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Shike H, Kadry Z, Imamura-Kawasawa Y, Greene W, Riley T, Nathan HM, Hasz RD, Jain A. Hepatitis C virus (HCV) RNA level in plasma and kidney tissue in HCV antibody-positive donors: Quantitative comparison. Clin Transplant 2018; 32:e13358. [PMID: 30044009 DOI: 10.1111/ctr.13358] [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] [Received: 08/28/2017] [Revised: 06/22/2018] [Accepted: 07/21/2018] [Indexed: 01/15/2023]
Abstract
Kidney transplant from donors with hepatitis C virus (HCV) antibody has been limited to HCV viremic recipients only, due to concern of the HCV transmission. However, the new antiviral medications provide an opportunity to expand the utilization of these donors. To study the risk of HCV transmission in kidney transplantation, we used discarded donor kidneys and determined HCV RNA levels by quantitative real-time PCR in bilateral (right and left) kidney biopsies and plasma from 14 HCV antibody-positive donors (sensitivity: 15 international unit (IU)/mL plasma; 1.8 IU/50 nL kidney). In three NAT-negative donors, HCV RNA was negative in plasma and kidney. In all 11 NAT-positive donors, HCV RNA was positive in plasma (range: 5807-19 134 177 IU/mL) but negative in six kidneys from four donors with plasma HCV RNA <1.5 million IU/μL. HCV RNA correlated between right and left kidneys (P = 0.75) and between kidney and plasma (r = 0.86). When normalized by volume, HCV RNA median (range) was 49 (0-957) IU/50 nL plasma and 1.0 (0-103) IU/50 nL kidney, significantly lower in kidney (P = 0.005) than in plasma (14-fold). Plasma HCV RNA can be used to predict the kidney HCV load. Future studies are needed if plasma/kidney HCV levels can be used to stratify donors for transmission risk and recipients for post-transplant management in extended utilization of HCV antibody-positive donors.
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Affiliation(s)
- Hiroko Shike
- Department of Pathology, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Zakiyah Kadry
- Division of Transplantation, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Yuka Imamura-Kawasawa
- Department of Pharmacology, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania.,Department of Biochemistry and Molecular Biology, Institute for Personalized Medicine, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Wallace Greene
- Department of Pathology, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Thomas Riley
- Division of Gastroenterology and Hepatology, Department of Medicine, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
| | - Howard M Nathan
- Gift of Life Donor Program, Organ Procurement Organization, Philadelphia, Pennsylvania
| | - Rick D Hasz
- Gift of Life Donor Program, Organ Procurement Organization, Philadelphia, Pennsylvania
| | - Ashokkumar Jain
- Division of Transplantation, Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania
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7
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Sekhar V, Pollicino T, Diaz G, Engle RE, Alayli F, Melis M, Kabat J, Tice A, Pomerenke A, Altan-Bonnet N, Zamboni F, Lusso P, Emerson SU, Farci P. Infection with hepatitis C virus depends on TACSTD2, a regulator of claudin-1 and occludin highly downregulated in hepatocellular carcinoma. PLoS Pathog 2018. [PMID: 29538454 PMCID: PMC5882150 DOI: 10.1371/journal.ppat.1006916] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Entry of hepatitis C virus (HCV) into hepatocytes is a complex process that involves numerous cellular factors, including the scavenger receptor class B type 1 (SR-B1), the tetraspanin CD81, and the tight junction (TJ) proteins claudin-1 (CLDN1) and occludin (OCLN). Despite expression of all known HCV-entry factors, in vitro models based on hepatoma cell lines do not fully reproduce the in vivo susceptibility of liver cells to primary HCV isolates, implying the existence of additional host factors which are critical for HCV entry and/or replication. Likewise, HCV replication is severely impaired within hepatocellular carcinoma (HCC) tissue in vivo, but the mechanisms responsible for this restriction are presently unknown. Here, we identify tumor-associated calcium signal transducer 2 (TACSTD2), one of the most downregulated genes in primary HCC tissue, as a host factor that interacts with CLDN1 and OCLN and regulates their cellular localization. TACSTD2 gene silencing disrupts the typical linear distribution of CLDN1 and OCLN along the cellular membrane in both hepatoma cells and primary human hepatocytes, recapitulating the pattern observed in vivo in primary HCC tissue. Mechanistic studies suggest that TACSTD2 is involved in the phosphorylation of CLDN1 and OCLN, which is required for their proper cellular localization. Silencing of TACSTD2 dramatically inhibits HCV infection with a pan-genotype effect that occurs at the level of viral entry. Our study identifies TACSTD2 as a novel regulator of two major HCV-entry factors, CLDN1 and OCLN, which is strongly downregulated in malignant hepatocytes. These results provide new insights into the complex process of HCV entry into hepatocytes and may assist in the development of more efficient cellular systems for HCV propagation in vitro.
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Affiliation(s)
- Vandana Sekhar
- Hepatic Pathogenesis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Teresa Pollicino
- Hepatic Pathogenesis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- Division of Clinical and Molecular Hepatology, Department of Human Pathology, University of Messina, Messina, Italy
| | - Giacomo Diaz
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy
| | - Ronald E. Engle
- Hepatic Pathogenesis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Farah Alayli
- Hepatic Pathogenesis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Marta Melis
- Hepatic Pathogenesis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Juraj Kabat
- Biological Imaging Facility/Research Technologies Branch, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ashley Tice
- Hepatic Pathogenesis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Anna Pomerenke
- Hepatic Pathogenesis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Nihal Altan-Bonnet
- Laboratory of Host-Pathogen Dynamics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Fausto Zamboni
- Liver Transplantation Center, Brotzu Hospital, Cagliari, Italy
| | - Paolo Lusso
- Viral Pathogenesis Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Suzanne U. Emerson
- Molecular Hepatitis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Patrizia Farci
- Hepatic Pathogenesis Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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8
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Goyal A, Lurie Y, Meissner EG, Major M, Sansone N, Uprichard SL, Cotler SJ, Dahari H. Modeling HCV cure after an ultra-short duration of therapy with direct acting agents. Antiviral Res 2017; 144:281-285. [PMID: 28673800 DOI: 10.1016/j.antiviral.2017.06.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 05/26/2017] [Accepted: 06/28/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cases of sustained-virological response (SVR or cure) after an ultra-short duration (≤27 days) of direct-acting antiviral (DAA)-based therapy, despite HCV being detected at end of treatment (EOT), have been reported. Established HCV mathematical models that predict the treatment duration required to achieve cure do not take into account the possibility that the infectivity of virus produced during treatment might be reduced. The aim of this study was to develop a new mathematical model that considers the fundamental and critical concept that HCV RNA in serum represents both infectious virus (Vi) and non-infectious virus (Vni) in order to explain the observation of cure with ultrashort DAA therapy. METHODS Established HCV models were compared to the new mathematical model to retrospectively explain cure in 2 patients who achieved cure after 24 or 27 days of paritaprevir, ombitasvir, dasabuvir, ritonavir and ribavirin or sofosbuvir plus ribavirin, respectively. RESULTS Fitting established models with measured longitudinal HCV viral loads indicated that in both cases, cure would not have been expected without an additional 3-6 weeks of therapy after the actual EOT. In contrast, the new model fits the observed outcome by considering that in addition to blocking Vi and Vni production (ε∼0.998), these DAA + ribavirin treatments further enhanced the ratio of Vni to Vi, thus increasing the log (Vni/Vi) from 1 at pretreatment to 6 by EOT, which led to <1 infectious-virus particle in the extracellular body fluid (i.e., cure) prior to EOT. CONCLUSIONS This new model can explain cure after short duration of DAA + ribavirin therapy by suggesting that a minimum 6-fold increase of log (Vni/Vi) results from drug-induced enhancement of the Vni/Vi.
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Affiliation(s)
- Ashish Goyal
- The Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Medical Center, Maywood, IL, United States; Theoretical Biology & Biophysics Group, Los Alamos National Laboratory, Los Alamos, NM, United States
| | - Yoav Lurie
- Liver Unit, Digestive Disease Institute, Sha'are Zedek Medical Center, Jerusalem, Israel
| | - Eric G Meissner
- Division of Infectious Diseases, Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, United States; Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Marian Major
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD, United States
| | - Natasha Sansone
- The Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Medical Center, Maywood, IL, United States; Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, IL, United States
| | - Susan L Uprichard
- The Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Medical Center, Maywood, IL, United States; Department of Microbiology and Immunology, University of Illinois Chicago, Chicago, IL, United States
| | - Scott J Cotler
- The Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Medical Center, Maywood, IL, United States
| | - Harel Dahari
- The Program for Experimental and Theoretical Modeling, Division of Hepatology, Department of Medicine, Loyola University Medical Center, Maywood, IL, United States.
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Singh A, Mankotia DS, Irshad M. A Single-step Multiplex Quantitative Real Time Polymerase Chain Reaction Assay for Hepatitis C Virus Genotypes. J Transl Int Med 2017; 5:34-42. [PMID: 28680837 DOI: 10.1515/jtim-2017-0010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND AND OBJECTIVES The variable response of hepatitis C virus (HCV) genotypes towards anti-viral treatment requires prior information on the genotype status before planning a therapeutic strategy. Although assays for typing or subtyping of HCV are available, however, a fast and reliable assay system is still needed. The present study was planned to develop a single-step multiplex quantitative real time polymerase chain reaction (qPCR) assay to determine HCV genotypes in patients' sera. METHODS The conserved sequences from 5' UTR, core and NS5b regions of HCV genome were used to design primers and hydrolysis probes labeled with fluorophores. Starting with the standardization of singleplex (qPCR) for each individual HCV-genotype, the experimental conditions were finally optimized for the development of multiplex assay. The sensitivity and specificity were assessed both for singleplex and multiplex assays. Using the template concentration of 102 copies per microliter, the value of quantification cycle (Cq) and the limit of detection (LOD) were also compared for both singleplex and multiplex assays. Similarly, the merit of multiplex assay was also compared with sequence analysis and restriction fragment length polymorphism (RFLP) techniques used for HCV genotyping. In order to find the application of multiplex qPCR assay, it was used for genotyping in a panel of 98 sera positive for HCV RNA after screening a total number of 239 patients with various liver diseases. RESULTS The results demonstrated the presence of genotype 1 in 26 of 98 (26.53%) sera, genotype 3 in 65 (66.32%) and genotype 4 in 2 (2.04%) sera samples, respectively. One sample showed mixed infection of genotype 1 and 3. Five samples could not show the presence of any genotype. Genotypes 2, 5 and 6 could not be detected in these sera samples. The analysis of sera by singleplex and RFLP indicated the results of multiplex to be comparable with singleplex and with clear merit of multiplex over RFLP. In addition, the results of multiplex assay were also found to be comparable with those from sequence analysis. The sensitivity, specificity, Cq values and LOD values were compared and found to be closely associated both for singleplex and multiplex assays. CONCLUSION The multiplex qPCR assay was found to be a fast, specific and sensitive method that can be used as a technique of choice for HCV genotyping in all routine laboratories.
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Affiliation(s)
- Akanksha Singh
- Clinical Biochemistry Division, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi-110029, India
| | - Dhananjay Singh Mankotia
- Clinical Biochemistry Division, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi-110029, India
| | - Mohammad Irshad
- Clinical Biochemistry Division, Department of Laboratory Medicine, All India Institute of Medical Sciences, New Delhi-110029, India
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10
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Diminished viral replication and compartmentalization of hepatitis C virus in hepatocellular carcinoma tissue. Proc Natl Acad Sci U S A 2016; 113:1375-80. [PMID: 26787866 DOI: 10.1073/pnas.1516879113] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Analysis of hepatitis C virus (HCV) replication and quasispecies distribution within the tumor of patients with HCV-associated hepatocellular carcinoma (HCC) can provide insight into the role of HCV in hepatocarcinogenesis and, conversely, the effect of HCC on the HCV lifecycle. In a comprehensive study of serum and multiple liver specimens from patients with HCC who underwent liver transplantation, we found a sharp and significant decrease in HCV RNA in the tumor compared with surrounding nontumorous tissues, but found no differences in multiple areas of control non-HCC cirrhotic livers. Diminished HCV replication was not associated with changes in miR-122 expression. HCV genetic diversity was significantly higher in livers containing HCC compared with control non-HCC cirrhotic livers. Tracking of individual variants demonstrated changes in the viral population between tumorous and nontumorous areas, the extent of which correlated with the decline in HCV RNA, suggesting HCV compartmentalization within the tumor. In contrast, compartmentalization was not observed between nontumorous areas and serum, or in controls between different areas of the cirrhotic liver or between liver and serum. Our findings indicate that HCV replication within the tumor is restricted and compartmentalized, suggesting segregation of specific viral variants in malignant hepatocytes.
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11
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Bukh J, Engle RE, Faulk K, Wang RY, Farci P, Alter HJ, Purcell RH. Immunoglobulin with High-Titer In Vitro Cross-Neutralizing Hepatitis C Virus Antibodies Passively Protects Chimpanzees from Homologous, but Not Heterologous, Challenge. J Virol 2015; 89:9128-32. [PMID: 26085160 PMCID: PMC4524056 DOI: 10.1128/jvi.01194-15] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Accepted: 06/15/2015] [Indexed: 12/21/2022] Open
Abstract
The importance of neutralizing antibodies (NAbs) in protection against hepatitis C virus (HCV) remains controversial. We infused a chimpanzee with H06 immunoglobulin from a genotype 1a HCV-infected patient and challenged with genotype strains efficiently neutralized by H06 in vitro. Genotype 1a NAbs afforded no protection against genotype 4a or 5a. Protection against homologous 1a lasted 18 weeks, but infection emerged when NAb titers waned. However, 6a infection was prevented. The differential in vivo neutralization patterns have implications for HCV vaccine development.
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Affiliation(s)
- Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital, and Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Ronald E Engle
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Kristina Faulk
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Richard Y Wang
- Department of Transfusion Medicine, Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Patrizia Farci
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Harvey J Alter
- Department of Transfusion Medicine, Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Robert H Purcell
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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12
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Engle RE, Bukh J, Alter HJ, Emerson SU, Trenbeath JL, Nguyen HT, Brockington A, Mitra T, Purcell RH. Transfusion-associated hepatitis before the screening of blood for hepatitis risk factors. Transfusion 2014; 54:2833-41. [PMID: 24797372 DOI: 10.1111/trf.12682] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/21/2014] [Accepted: 03/07/2014] [Indexed: 12/24/2022]
Abstract
BACKGROUND The true incidence of transfusion-associated hepatitis (TAH) before blood screening is unknown. Our aims were to reevaluate blood recipients receiving unscreened blood and analyze hepatitis viruses circulating more than 45 years ago. STUDY DESIGN AND METHODS Cryopreserved serum samples from 66 patients undergoing open heart surgery in the 1960s were reevaluated with modern diagnostic tests to determine the incidence of TAH and its virologic causes. RESULTS In this heavily transfused population receiving a mean of 20 units per patient of predominantly paid-donor blood, 30 of 66 (45%) developed biochemical evidence of hepatitis; of these, 20 (67%) were infected with hepatitis C virus (HCV) alone, four (13%) with hepatitis B virus (HBV) alone, and six (20%) with both viruses. Among the 36 patients who did not develop hepatitis, four (11%) were newly infected with HCV alone, nine (25%) with HBV alone, and one (3%) with both viruses. Overall, 100% of patients with hepatitis and 39% of those without hepatitis were infected with HBV and/or HCV; one patient was also infected with hepatitis E virus. The donor carrier rate for HBV and/or HCV was estimated to be more than 6%; contemporaneously prepared pooled normal human plasma was also contaminated with multiple hepatitis viruses. CONCLUSION TAH virus infections were a larger problem than perceived 50 years ago and HCV was the predominant agent transmitted. All hepatitis cases could be attributed to HCV and/or HBV and hence there was no evidence to suggest that an additional hepatitis agent existed undetected in the blood supply.
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Affiliation(s)
- Ronald E Engle
- Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
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13
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Mixson-Hayden T, Lee D, Ganova-Raeva L, Drobeniuc J, Stauffer WM, Teshale E, Kamili S. Hepatitis B virus and hepatitis C virus infections in United States-bound refugees from Asia and Africa. Am J Trop Med Hyg 2014; 90:1014-20. [PMID: 24732462 DOI: 10.4269/ajtmh.14-0068] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The aim of this study was to determine the prevalence of active hepatitis B and C virus infections among refugees from various countries in Africa and Asia. Pre-admission serum samples collected during 2002-2007 from refugees originating from Bhutan (N = 755), Myanmar (N = 1076), Iraq (N = 1137), Laos (N = 593), Thailand (N = 622), and Somalia (N = 707) were tested for hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA. The HBV DNA (genotypes A, B, C, and G) was detected in 12.1% of samples negative for anti-HBs. Highest HBV prevalence was found among Hmong; lowest among Bhutanese. The HCV RNA (genotypes 1a, 1b, 1c, 3b, 6n, and 6m) was detected in 1.3% of the samples. Highest HCV prevalence was found among Hmong from Thailand; lowest among Iraqis. Screening specific refugee groups at high risk for viral hepatitis infections will identify infected individuals who could benefit from referral to care and treatment and prevent further transmissions.
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Affiliation(s)
- Tonya Mixson-Hayden
- Centers for Disease Control and Prevention, Division of Viral Hepatitis, Atlanta, Georgia; University of Minnesota, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Deborah Lee
- Centers for Disease Control and Prevention, Division of Viral Hepatitis, Atlanta, Georgia; University of Minnesota, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Lilia Ganova-Raeva
- Centers for Disease Control and Prevention, Division of Viral Hepatitis, Atlanta, Georgia; University of Minnesota, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Jan Drobeniuc
- Centers for Disease Control and Prevention, Division of Viral Hepatitis, Atlanta, Georgia; University of Minnesota, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, Minnesota
| | - William M Stauffer
- Centers for Disease Control and Prevention, Division of Viral Hepatitis, Atlanta, Georgia; University of Minnesota, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Eyasu Teshale
- Centers for Disease Control and Prevention, Division of Viral Hepatitis, Atlanta, Georgia; University of Minnesota, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Saleem Kamili
- Centers for Disease Control and Prevention, Division of Viral Hepatitis, Atlanta, Georgia; University of Minnesota, Division of Infectious Diseases and International Medicine, University of Minnesota, Minneapolis, Minnesota
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14
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Hepatitis C virus infection upregulates CD55 expression on the hepatocyte surface and promotes association with virus particles. J Virol 2013; 87:7902-10. [PMID: 23658447 DOI: 10.1128/jvi.00917-13] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
CD55 limits excessive complement activation on the host cell surface by accelerating the decay of C3 convertases. In this study, we observed that hepatitis C virus (HCV) infection of hepatocytes or HCV core protein expression in transfected hepatocytes upregulated CD55 expression at the mRNA and protein levels. Further analysis suggested that the HCV core protein or full-length (FL) genome enhanced CD55 promoter activity in a luciferase-based assay, which was further augmented in the presence of interleukin-6. Mutation of the CREB or SP-1 binding site on the CD55 promoter impaired HCV core protein-mediated upregulation of CD55. HCV-infected or core protein-transfected Huh7.5 cells displayed greater viability in the presence of CD81 and CD55 antibodies and complement. Biochemical analysis revealed that CD55 was associated with cell culture-grown HCV after purification by sucrose density gradient ultracentrifugation. Consistent with this, a polyclonal antibody to CD55 captured cell culture-grown HCV. Blocking antibodies against CD55 or virus envelope glycoproteins in the presence of normal human serum as a source of complement inhibited HCV infection. The inhibition was enhanced in the presence of both the antibodies and serum complement. Collectively, these results suggest that HCV induces and associates with a negative regulator of the complement pathway, a likely mechanism for immune evasion.
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15
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Robust full-length hepatitis C virus genotype 2a and 2b infectious cultures using mutations identified by a systematic approach applicable to patient strains. Proc Natl Acad Sci U S A 2012; 109:E1101-10. [PMID: 22467829 DOI: 10.1073/pnas.1203829109] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Hepatitis C virus (HCV) infection is a leading cause of chronic liver diseases worldwide, but treatment options are limited. Basic HCV research required for vaccine and drug development has been hampered by inability to culture patient isolates, and to date only the JFH1 (genotype 2a) recombinant replicates spontaneously in hepatoma cells and releases infectious virus. A JFH1 chimera with the 5' end through NS2 from another genotype 2a strain, J6, had enhanced infectivity. However, the full-length J6 clone (J6CF), which we previously found to be fully functional in vivo, was replication incompetent in vitro. Through a systematic approach of culturing J6 with minimal JFH1 sequences, we identified three mutations in NS3, NS4A, and NS5B that permitted full-length J6 propagation and adaptation with infectivity titers comparable to JFH1-based systems. The most efficient recombinant, J6cc, had six adaptive mutations and did not accumulate additional changes following viral passage. We demonstrated that HCV NS3/NS4A protease-, NS5A- and NS5B polymerase-directed drugs respectively inhibited full-length J6 infection dose dependently. Importantly, the three J6-derived mutations enabled culture adaptation of the genetically divergent isolate J8 (genotype 2b), which differed from the J6 nucleotide sequence by 24%. The most efficient recombinant, J8cc, had nine adaptive mutations and was genetically stable after viral passage. The availability of these robust JFH1-independent genotype 2a and 2b culture systems represents an important advance, and the approach used might permit culture development of other isolates, with implications for improved individualized treatments of HCV patients and for development of broadly efficient vaccines.
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16
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A weak neutralizing antibody response to hepatitis C virus envelope glycoprotein enhances virus infection. PLoS One 2011; 6:e23699. [PMID: 21887300 PMCID: PMC3161815 DOI: 10.1371/journal.pone.0023699] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2011] [Accepted: 07/22/2011] [Indexed: 01/26/2023] Open
Abstract
We have completed a phase 1 safety and immunogenicity trial with hepatitis C virus (HCV) envelope glycoproteins, E1 and E2, with MF59 adjuvant as a candidate vaccine. Neutralizing activity to HCV genotype 1a was detected in approximately 25% of the vaccinee sera. In this study, we evaluated vaccinee sera from poor responders as a potential source of antibody dependent enhancement (ADE) of HCV infection. Sera with poor neutralizing activity enhanced cell culture grown HCV genotype 1a or 2a, and surrogate VSV/HCV pseudotype infection titer, in a dilution dependent manner. Surrogate pseudotypes generated from individual HCV glycoproteins suggested that antibody to the E2 glycoprotein; but not the E1 glycoprotein, was the principle target for enhancing infection. Antibody specific to FcRII expressed on the hepatic cell surface or to the Fc portion of Ig blocked enhancement of HCV infection by vaccinee sera. Together, the results from in vitro studies suggested that enhancement of viral infectivity may occur in the absence of a strong antibody response to HCV envelope glycoproteins.
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17
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Molecular Detection and Characterization of Hepatitis C Virus. Mol Microbiol 2011. [DOI: 10.1128/9781555816834.ch36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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Dahari H, Feinstone SM, Major ME. Meta-analysis of hepatitis C virus vaccine efficacy in chimpanzees indicates an importance for structural proteins. Gastroenterology 2010; 139:965-74. [PMID: 20621699 PMCID: PMC3075980 DOI: 10.1053/j.gastro.2010.05.077] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 05/06/2010] [Accepted: 05/26/2010] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS Studies in patients and chimpanzees that spontaneously cleared hepatitis C virus (HCV) infections demonstrated that natural immunity to the virus is induced during primary infections and that this immunity can be cross protective. These discoveries led to optimism about prophylactic HCV vaccines, and several studies were performed in chimpanzees, although most included fewer than 6 animals. To draw meaningful conclusions about the efficacy of HCV vaccines in chimpanzees, we performed statistical analyses of data from previously published studies from different groups. METHODS We performed a meta-analysis that compared parameters among naïve (n = 63), vaccinated (n = 53), and rechallenged (n = 36) animals, including peak RNA titer postchallenge, time points of peak RNA titer, duration of viremia, and proportion of persistent infections. RESULTS Each vaccination study induced immune responses that were effective in rapidly controlling HCV replication. Levels of induced T-cell responses did not indicate vaccine success. There was no reduction in the rate of HCV persistence in vaccinated animals, compared with naïve animals, when nonstructural proteins were included in the vaccine. Vaccines that contained only structural proteins had clearance rates that were significantly higher than vaccines that contained nonstructural components (P = .015). CONCLUSIONS The inclusion of nonstructural proteins in HCV vaccines might be detrimental to protective immune responses, and/or structural proteins might activate T-cell responses that mediate viral clearance.
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Affiliation(s)
- Harel Dahari
- Department of Medicine, The University of Illinois at Chicago, Chicago, IL 60612 USA
| | - Stephen M. Feinstone
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 USA
| | - Marian E. Major
- Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 USA
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Fofana I, Krieger SE, Grunert F, Glauben S, Xiao F, Fafi-Kremer S, Soulier E, Royer C, Thumann C, Mee CJ, McKeating JA, Dragic T, Pessaux P, Stoll-Keller F, Schuster C, Thompson J, Baumert TF. Monoclonal anti-claudin 1 antibodies prevent hepatitis C virus infection of primary human hepatocytes. Gastroenterology 2010; 139:953-64, 964.e1-4. [PMID: 20685314 DOI: 10.1053/j.gastro.2010.05.073] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 05/12/2010] [Accepted: 05/24/2010] [Indexed: 12/24/2022]
Abstract
BACKGROUND & AIMS Hepatitis C virus (HCV) infection is a challenge to prevent and treat because of the rapid development of drug resistance and escape. Viral entry is required for initiation, spread, and maintenance of infection, making it an attractive target for antiviral strategies. The tight junction protein claudin-1 (CLDN1) has been shown to be required for entry of HCV into the cell. METHODS Using genetic immunization, we produced 6 monoclonal antibodies against the host entry factor CLDN1. The effects of antibodies on HCV infection were analyzed in human cell lines and primary human hepatocytes. RESULTS Competition and binding studies demonstrated that antibodies interacted with conformational epitopes of the first extracellular loop of CLDN1; binding of these antibodies required the motif W(30)-GLW(51)-C(54)-C(64) and residues in the N-terminal third of CLDN1. The monoclonal antibodies against CLDN1 efficiently inhibited infection by HCV of all major genotypes as well as highly variable HCV quasispecies isolated from individual patients. Furthermore, antibodies efficiently blocked cell entry of highly infectious escape variants of HCV that were resistant to neutralizing antibodies. CONCLUSIONS Monoclonal antibodies against the HCV entry factor CLDN1 might be used to prevent HCV infection, such as after liver transplantation, and might also restrain virus spread in chronically infected patients.
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Pathogenesis of hepatitis E virus and hepatitis C virus in chimpanzees: similarities and differences. J Virol 2010; 84:11264-78. [PMID: 20739520 DOI: 10.1128/jvi.01205-10] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The chimpanzee is the only animal model for investigating the pathogenesis of viral hepatitis types A through E in humans. Studies of the host response, including microarray analyses, have relied on the close relationship between these two primate species: chimpanzee samples are commonly tested with human-based reagents. In this study, the host responses to two dissimilar viruses, hepatitis E virus (HEV) and hepatitis C virus (HCV), were compared in multiple experimentally infected chimpanzees. Affymetrix U133+2.0 human microarray chips were used to assess the entire transcriptome in serial liver biopsies obtained over the course of the infections. Respecting the limitations of microarray probes designed for human target transcripts to effectively assay chimpanzee transcripts, we conducted probe-level analysis of the microarray data in conjunction with a custom mapping of the probe sequences to the most recent human and chimpanzee genome sequences. Time points for statistical comparison were chosen based on independently measured viremia levels. Regardless of the viral infection, the alignment of differentially expressed genes to the human genome sequence resulted in a larger number of genes being identified when compared with alignment to the chimpanzee genome sequence. This probably reflects the lesser refinement of gene annotation for chimpanzees. In general, the two viruses demonstrated very distinct temporal changes in host response genes, although both RNA viruses induced genes that were involved in many of the same biological systems, including interferon-induced genes. The host response to HCV infection was more robust in the magnitude and number of differentially expressed genes compared to HEV infection.
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Bukh J, Meuleman P, Tellier R, Engle RE, Feinstone SM, Eder G, Satterfield WC, Govindarajan S, Krawczynski K, Miller RH, Leroux-Roels G, Purcell RH. Challenge pools of hepatitis C virus genotypes 1-6 prototype strains: replication fitness and pathogenicity in chimpanzees and human liver-chimeric mouse models. J Infect Dis 2010; 201:1381-9. [PMID: 20353362 PMCID: PMC2941994 DOI: 10.1086/651579] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Chimpanzees represent the only animal model for studies of the natural history of hepatitis C virus (HCV). To generate virus stocks of important HCV variants, we infected chimpanzees with HCV strains of genotypes 1-6 and determined the infectivity titer of acute-phase plasma pools in additional animals. The courses of first- and second-passage infections were similar, with early appearance of viremia, HCV RNA titers of >10(4.7) IU/mL, and development of acute hepatitis; the chronicity rate was 56%. The challenge pools had titers of 10(3)-10(5) chimpanzee infectious doses/mL. Human liver-chimeric mice developed high-titer infections after inoculation with the challenge viruses of genotypes 1-6. Inoculation studies with different doses of the genotype 1b pool suggested that a relatively high virus dose is required to consistently infect chimeric mice. The challenge pools represent a unique resource for studies of HCV molecular virology and for studies of pathogenesis, protective immunity, and vaccine efficacy in vivo.
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Affiliation(s)
- Jens Bukh
- Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bldg 50, 50 S Dr MSC 8009, Bethesda, MD 20892-8009, USA.
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22
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Gottwein JM, Scheel TKH, Callendret B, Li YP, Eccleston HB, Engle RE, Govindarajan S, Satterfield W, Purcell RH, Walker CM, Bukh J. Novel infectious cDNA clones of hepatitis C virus genotype 3a (strain S52) and 4a (strain ED43): genetic analyses and in vivo pathogenesis studies. J Virol 2010; 84:5277-93. [PMID: 20200247 PMCID: PMC2863810 DOI: 10.1128/jvi.02667-09] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 02/19/2010] [Indexed: 12/19/2022] Open
Abstract
Previously, RNA transcripts of cDNA clones of hepatitis C virus (HCV) genotypes 1a (strains H77, HCV-1, and HC-TN), 1b (HC-J4, Con1, and HCV-N), and 2a (HC-J6 and JFH1) were found to be infectious in chimpanzees. However, only JFH1 was infectious in human hepatoma Huh7 cells. We performed genetic analysis of HCV genotype 3a (strain S52) and 4a (strain ED43) prototype strains and generated full-length consensus cDNA clones (pS52 and pED43). Transfection of Huh7.5 cells with RNA transcripts of these clones did not yield cells expressing HCV Core. However, intrahepatic transfection of chimpanzees resulted in robust infection with peak HCV RNA titers of approximately 5.5 log(10) international units (IU)/ml. Genomic consensus sequences recovered from serum at the times of peak viral titers were identical to the sequences of the parental plasmids. Both chimpanzees developed acute hepatitis with elevated liver enzymes and significant necroinflammatory liver changes coinciding with detection of gamma interferon-secreting, intrahepatic T cells. However, the onset and broadness of intrahepatic T-cell responses varied greatly in the two animals, with an early (week 4) multispecific response in the ED43-infected animal (3 weeks before the first evidence of viral control) and a late (week 11) response with limited breadth in the S52-infected animal (without evidence of viral control). Autologous serum neutralizing antibodies were not detected during the acute infection in either animal. Both animals became persistently infected. In conclusion, we generated fully functional infectious cDNA clones of HCV genotypes 3a and 4a. Proof of functionality of all genes might further the development of recombinant cell culture systems for these important genotypes.
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Affiliation(s)
- Judith M. Gottwein
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - Troels K. H. Scheel
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - Benoit Callendret
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - Yi-Ping Li
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - Heather B. Eccleston
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - Ronald E. Engle
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - Sugantha Govindarajan
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - William Satterfield
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - Robert H. Purcell
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - Christopher M. Walker
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
| | - Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark, The Center for Vaccines and Immunity, Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University, Columbus, Ohio, Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, Liver Research Laboratory, Rancho Los Amigos Medical Center, Downey, California, Department of Veterinary Sciences, Michale E. Keeling Center for Comparative Medicine and Research, M. D. Anderson Cancer Center, Bastrop, Texas
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23
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Gottwein JM, Scheel TKH, Jensen TB, Lademann JB, Prentoe JC, Knudsen ML, Hoegh AM, Bukh J. Development and characterization of hepatitis C virus genotype 1-7 cell culture systems: role of CD81 and scavenger receptor class B type I and effect of antiviral drugs. Hepatology 2009; 49:364-77. [PMID: 19148942 DOI: 10.1002/hep.22673] [Citation(s) in RCA: 300] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
UNLABELLED Six major hepatitis C virus (HCV) genotypes and numerous subtypes have been described, and recently a seventh major genotype was discovered. Genotypes show significant molecular and clinical differences, such as differential response to combination therapy with interferon-alpha and ribavirin. Recently, HCV research has been accelerated by cell culture systems based on the unique growth capacity of strain JFH1 (genotype 2a). By development of JFH1-based intergenotypic recombinants containing Core, envelope protein 1 and 2 (E1, E2), p7, and nonstructural protein 2 (NS2) of genotype 6a and 7a strains, as well as subtype 1b and 2b strains, we have completed a panel of culture systems for all major HCV genotypes. Efficient growth in Huh7.5 cells depended on adaptive mutations for HK6a/JFH1 (6a/2a, in E1 and E2) and J4/JFH1 (1b/2a, in NS2 and NS3); viability of J8/JFH1 (2b/2a) and QC69/JFH1 (7a/2a) did not require adaptation. To facilitate comparative studies, we generated virus stocks of genotype 1-7 recombinants with infectivity titers of 10(3.7) to 10(5.2) 50% tissue culture infectious dose/mL and HCV RNA titers of 10(7.0) to 10(7.9) IU/mL. Huh7.5 cultures infected with genotype 1-6 viruses had similar spread kinetics, intracellular Core, NS5A, and lipid amounts, and colocalization of Core and NS5A with lipids. Treatment with interferon-alpha2b but not ribavirin or amantadine showed a significant antiviral effect. Infection with all genotypes could be blocked by specific antibodies against the putative coreceptors CD81 and scavenger receptor class B type I in a dose-dependent manner. Finally, neutralizing antibodies in selected chronic phase HCV sera had differential effects against genotype 1-7 viruses. CONCLUSION We completed and characterized a panel of JFH1-based cell culture systems of all seven major HCV genotypes and important subtypes and used these viruses in comparative studies of antivirals, HCV receptor interaction, and neutralizing antibodies.
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Affiliation(s)
- Judith M Gottwein
- Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark
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Abstract
PURPOSE OF REVIEW The purpose of this article is to review the molecular methods commonly used in medical microbiology as well as to update the clinician as to newer molecular technologies that show promise in the identification of microorganisms as well as evaluation of the presence of virulence factors and antibiotic resistance determinants. RECENT FINDINGS Numerous molecular assays have been developed recently using a variety of technologies. Direct hybridization techniques have allowed analysis of blood culture bottles for organisms such as methicillin-resistant Staphylococcus aureus. Target amplification methods allow postamplification analysis using a variety of technologies depending on the clinical needs for the assay. Postamplification analysis includes methods such as Sanger sequencing, pyrosequencing, reverse hybridization, and Luminex analysis, which are becoming more widely utilized. In the future, whole genome sequencing, mass spectrometry, and microarray analysis may provide a wealth of information that can be used to specifically tailor the treatment of infectious diseases. SUMMARY The implications of current trends in molecular infectious diseases are moving towards high-throughput, simple, array-type technologies that will provide a wealth of data regarding types of organisms present in a sample and the virulence factors/resistance determinants that influence the severity of disease. As a result of these developments, infectious diseases will be more accurately and effectively treated.
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Advantages of a single-cycle production assay to study cell culture-adaptive mutations of hepatitis C virus. Proc Natl Acad Sci U S A 2008; 105:4370-5. [PMID: 18334634 DOI: 10.1073/pnas.0800422105] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The JFH1 strain of hepatitis C virus (HCV) is unique among HCV isolates, in that the wild-type virus can traverse the entire replication cycle in cultured cells. However, without adaptive mutations, only low levels of infectious virus are produced. In the present study, the effects of five mutations that were selected during serial passage in Huh-7.5 cells were studied. Recombinant genomes containing all five mutations produced 3-4 logs more infectious virions than did wild type. Neither a coding mutation in NS5A nor a silent mutation in E2 was adaptive, whereas coding mutations in E2, p7, and NS2 all increased virus production. A single-cycle replication assay in CD81-deficient cells was developed to study more precisely the effect of the adaptive mutations. The E2 mutation had minimal effect on the amount of infectious virus released but probably enhanced entry into cells. In contrast, both the p7 and NS2 mutations independently increased the amount of virus released.
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