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Rheault M, Cousineau SE, Fox DR, Abram QH, Sagan S. Elucidating the distinct contributions of miR-122 in the HCV life cycle reveals insights into virion assembly. Nucleic Acids Res 2023; 51:2447-2463. [PMID: 36807979 PMCID: PMC10018354 DOI: 10.1093/nar/gkad094] [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: 10/15/2022] [Revised: 01/20/2023] [Accepted: 02/18/2023] [Indexed: 02/23/2023] Open
Abstract
Efficient hepatitis C virus (HCV) RNA accumulation is dependent upon interactions with the human liver-specific microRNA, miR-122. MiR-122 has at least three roles in the HCV life cycle: it acts as an RNA chaperone, or 'riboswitch', allowing formation of the viral internal ribosomal entry site; it provides genome stability; and promotes viral translation. However, the relative contribution of each role in HCV RNA accumulation remains unclear. Herein, we used point mutations, mutant miRNAs, and HCV luciferase reporter RNAs to isolate each of the roles and evaluate their contribution to the overall impact of miR-122 in the HCV life cycle. Our results suggest that the riboswitch has a minimal contribution in isolation, while genome stability and translational promotion have similar contributions in the establishment phase of infection. However, in the maintenance phase, translational promotion becomes the dominant role. Additionally, we found that an alternative conformation of the 5' untranslated region, termed SLIIalt, is important for efficient virion assembly. Taken together, we have clarified the overall importance of each of the established roles of miR-122 in the HCV life cycle and provided insight into the regulation of the balance between viral RNAs in the translating/replicating pool and those engaged in virion assembly.
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Affiliation(s)
- Marylin Rheault
- Department of Microbiology & Immunology, McGill University, Montréal, Canada
| | - Sophie E Cousineau
- Department of Microbiology & Immunology, McGill University, Montréal, Canada
| | - Danielle R Fox
- Department of Microbiology & Immunology, McGill University, Montréal, Canada
- Department of Physiology, McGill University, Montréal, Canada
| | - Quinn H Abram
- Department of Biochemistry, McGill University, Montréal, Canada
| | - Selena M Sagan
- To whom correspondence should be addressed. Tel: +1 514 398 8110;
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HCV p7 as a novel vaccine-target inducing multifunctional CD4 + and CD8 + T-cells targeting liver cells expressing the viral antigen. Sci Rep 2019; 9:14085. [PMID: 31575882 PMCID: PMC6773770 DOI: 10.1038/s41598-019-50365-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 09/11/2019] [Indexed: 02/07/2023] Open
Abstract
Despite recent treatment advances for chronic hepatitis C virus (HCV) infection, a vaccine is urgently needed for global control of this important liver pathogen. The lack of robust immunocompetent HCV infection models makes it challenging to identify correlates of protection and test vaccine efficacy. However, vigorous CD4+ and CD8+ T-cell responses are detected in patients that spontaneously resolve acute infection, whereas dysfunctional T-cell responses are a hallmark of chronic infection. The HCV p7 protein, forming ion-channels essential for viral assembly and release, has not previously been pursued as a vaccine antigen. Herein, we demonstrated that HCV p7 derived from genotype 1a and 1b sequences are highly immunogenic in mice when employed as overlapping peptides formulated as nanoparticles with the cross-priming adjuvant, CAF09. This approach induced multifunctional cytokine producing CD4+ and CD8+ T-cells targeting regions of p7 that are subject to immune pressure during HCV infection in chimpanzees and humans. Employing a surrogate in vivo challenge model of liver cells co-expressing HCV-p7 and GFP, we found that vaccinated mice cleared transgene expressing cells. This study affirms the potential of a T-cell inducing nanoparticle vaccine platform to target the liver and introduces HCV p7 as a potential target for HCV vaccine explorations.
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Ramirez S, Bukh J. Current status and future development of infectious cell-culture models for the major genotypes of hepatitis C virus: Essential tools in testing of antivirals and emerging vaccine strategies. Antiviral Res 2018; 158:264-287. [PMID: 30059723 DOI: 10.1016/j.antiviral.2018.07.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 07/17/2018] [Accepted: 07/20/2018] [Indexed: 02/08/2023]
Abstract
In this review, we summarize the relevant scientific advances that led to the development of infectious cell culture systems for hepatitis C virus (HCV) with the corresponding challenges and successes. We also provide an overview of how these systems have contributed to the study of antiviral compounds and their relevance for the development of a much-needed vaccine against this major human pathogen. An efficient infectious system to study HCV in vitro, using human hepatoma derived cells, has only been available since 2005, and was limited to a single isolate, named JFH1, until 2012. Successive developments have been slow and cumbersome, as each available system has been the result of a systematic effort for discovering adaptive mutations conferring culture replication and propagation to patient consensus clones that are inherently non-viable in vitro. High genetic heterogeneity is a paramount characteristic of this virus, and as such, it should preferably be reflected in basic, translational, and clinical studies. The limited number of efficient viral culture systems, in the context of the vast genetic diversity of HCV, continues to represent a major hindrance for the study of this virus, posing a significant barrier towards studies of antivirals (particularly of resistance) and for advancing vaccine development. Intensive research efforts, driven by isolate-specific culture adaptation, have only led to efficient full-length infectious culture systems for a few strains of HCV genotypes 1, 2, 3, and 6. Hence research aimed at identifying novel strategies that will permit universal culture of HCV will be needed to further our understanding of this unique virus causing 400 thousand deaths annually.
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Affiliation(s)
- 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, 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, Denmark.
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Humes D, Ramirez S, Jensen TB, Li YP, Gottwein JM, Bukh J. Recombinant hepatitis C virus genotype 5a infectious cell culture systems expressing minimal JFH1 NS5B sequences permit polymerase inhibitor studies. Virology 2018; 522:177-192. [PMID: 30032031 DOI: 10.1016/j.virol.2018.05.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 05/24/2018] [Accepted: 05/25/2018] [Indexed: 02/07/2023]
Abstract
The six major epidemiologically important hepatitis C virus (HCV) genotypes differ in global distribution and antiviral responses. Full-length infectious cell-culture adapted clones, the gold standard for HCV studies in vitro, are missing for genotypes 4 and 5. To address this challenge for genotype 5, we constructed a consensus full-length clone of strain SA13 (SA13fl), which was found non-viable in Huh7.5 cells. Step-wise adaptation of SA13fl-based recombinants, beginning with a virus encoding the NS5B-thumb domain and 3´UTR of JFH1 (SA13/JF372-X), resulted in a high-titer SA13 virus with only 41 JFH1-encoded NS5B-thumb residues (SA13/JF470-510cc); this required sixteen cell-culture adaptive substitutions within the SA13fl polyprotein and two 3´UTR-changes. SA13/JF372-X and SA13/JF470-510cc were equally sensitive to nucleoside polymerase inhibitors, including sofosbuvir, but showed differential sensitivity to inhibitors targeting the NS5B palm or thumb. SA13/JF470-510cc represents a model to elucidate the influence of HCV RNA elements on viral replication and map determinants of sensitivity to polymerase inhibitors.
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Affiliation(s)
- Daryl Humes
- 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, Denmark
| | - Santseharay Ramirez
- 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, Denmark
| | - Tanja B Jensen
- 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, Denmark
| | - Yi-Ping Li
- 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, Denmark
| | - Judith M Gottwein
- 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, Denmark
| | - 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, Denmark.
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Bukh J. The history of hepatitis C virus (HCV): Basic research reveals unique features in phylogeny, evolution and the viral life cycle with new perspectives for epidemic control. J Hepatol 2016; 65:S2-S21. [PMID: 27641985 DOI: 10.1016/j.jhep.2016.07.035] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 07/29/2016] [Indexed: 12/11/2022]
Abstract
The discovery of hepatitis C virus (HCV) in 1989 permitted basic research to unravel critical components of a complex life cycle for this important human pathogen. HCV is a highly divergent group of viruses classified in 7 major genotypes and a great number of subtypes, and circulating in infected individuals as a continuously evolving quasispecies destined to escape host immune responses and applied antivirals. Despite the inability to culture patient viruses directly in the laboratory, efforts to define the infectious genome of HCV resulted in development of experimental recombinant in vivo and in vitro systems, including replicons and infectious cultures in human hepatoma cell lines. And HCV has become a model virus defining new paradigms in virology, immunology and biology. For example, HCV research discovered that a virus could be completely dependent on microRNA for its replication since microRNA-122 is critical for the HCV life cycle. A number of other host molecules critical for HCV entry and replication have been identified. Thus, basic HCV research revealed important molecules for development of host targeting agents (HTA). The identification and characterization of HCV encoded proteins and their functional units contributed to the development of highly effective direct acting antivirals (DAA) against the NS3 protease, NS5A and the NS5B polymerase. In combination, these inhibitors have since 2014 permitted interferon-free therapy with cure rates above 90% among patients with chronic HCV infection; however, viral resistance represents a challenge. Worldwide control of HCV will most likely require the development of a prophylactic vaccine, and numerous candidates have been pursued. Research characterizing features critical for antibody-based virus neutralization and T cell based virus elimination from infected cells is essential for this effort. If the world community promotes an ambitious approach by applying current DAA broadly, continues to develop alternative viral- and host- targeted antivirals to combat resistant variants, and invests in the development of a vaccine, it would be possible to eradicate HCV. This would prevent about 500 thousand deaths annually. However, given the nature of HCV, the millions of new infections annually, a high chronicity rate, and with over 150 million individuals with chronic infection (which are frequently unidentified), this effort remains a major challenge for basic researchers, clinicians and communities.
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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, Denmark.
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Substitutions at NS3 Residue 155, 156, or 168 of Hepatitis C Virus Genotypes 2 to 6 Induce Complex Patterns of Protease Inhibitor Resistance. Antimicrob Agents Chemother 2015; 59:7426-36. [PMID: 26392503 DOI: 10.1128/aac.01953-15] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 09/10/2015] [Indexed: 01/14/2023] Open
Abstract
Various protease inhibitors (PIs) currently are becoming available for treatment of hepatitis C virus (HCV). For genotype 1, substitutions at NS3 protease positions 155, 156, and 168 are the main determinants of PI resistance. For other genotypes, similar substitutions were selected during PI treatment but were not characterized systematically. To elucidate the impact of key PI resistance substitutions on genotypes 2 to 6, we engineered the substitutions R155A/E/G/H/K/Q/T, A156G/S/T/V, and D/Q168A/E/G/H/N/V into HCV recombinants expressing genotype 2 to 6 proteases. We evaluated viral fitness and sensitivity to nine PIs (telaprevir, boceprevir, simeprevir, asunaprevir, vaniprevir, faldaprevir, paritaprevir, deldeprevir, and grazoprevir) in Huh7.5 cells. We found that most variants showed decreased fitness compared to that of the original viruses. Overall, R155K, A156G/S, and D/Q168A/E/H/N/V variants showed the highest fitness; however, genotype 4 position 168 variants showed strong fitness impairment. Most variants tested were resistant to several PIs. Resistance levels varied significantly depending on the specific substitution, genotype, and PI. For telaprevir and boceprevir, specific 155 and 156, but not 168, variants proved resistant. For the remaining PIs, most genotype 2, 4, 5, and 6, but not genotype 3, variants showed various resistance levels. Overall, grazoprevir (MK-5172) had the highest efficacy against original viruses and variants. This is the first comprehensive study revealing the impact of described key PI resistance substitutions on fitness and PI resistance of HCV genotypes 2 to 6. In conclusion, the studied substitutions induced resistance to a panel of clinically relevant PIs, including the newer PIs paritaprevir, deldeprevir, and grazoprevir. We discovered complex patterns of resistance, with the impact of substitutions varying from increased sensitivity to high resistance.
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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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Efficient infectious cell culture systems of the hepatitis C virus (HCV) prototype strains HCV-1 and H77. J Virol 2014; 89:811-23. [PMID: 25355880 DOI: 10.1128/jvi.02877-14] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
UNLABELLED The first discovered and sequenced hepatitis C virus (HCV) genome and the first in vivo infectious HCV clones originated from the HCV prototype strains HCV-1 and H77, respectively, both widely used in research of this important human pathogen. In the present study, we developed efficient infectious cell culture systems for these genotype 1a strains by using the HCV-1/SF9_A and H77C in vivo infectious clones. We initially adapted a genome with the HCV-1 5'UTR-NS5A (where UTR stands for untranslated region) and the JFH1 NS5B-3'UTR (5-5A recombinant), including the genotype 2a-derived mutations F1464L/A1672S/D2979G (LSG), to grow efficiently in Huh7.5 cells, thus identifying the E2 mutation S399F. The combination of LSG/S399F and reported TNcc(1a)-adaptive mutations A1226G/Q1773H/N1927T/Y2981F/F2994S promoted adaptation of the full-length HCV-1 clone. An HCV-1 recombinant with 17 mutations (HCV1cc) replicated efficiently in Huh7.5 cells and produced supernatant infectivity titers of 10(4.0) focus-forming units (FFU)/ml. Eight of these mutations were identified from passaged HCV-1 viruses, and the A970T/I1312V/C2419R/A2919T mutations were essential for infectious particle production. Using CD81-deficient Huh7 cells, we further demonstrated the importance of A970T/I1312V/A2919T or A970T/C2419R/A2919T for virus assembly and that the I1312V/C2419R combination played a major role in virus release. Using a similar approach, we found that NS5B mutation F2994R, identified here from culture-adapted full-length TN viruses and a common NS3 helicase mutation (S1368P) derived from viable H77C and HCV-1 5-5A recombinants, initiated replication and culture adaptation of H77C containing LSG and TNcc(1a)-adaptive mutations. An H77C recombinant harboring 19 mutations (H77Ccc) replicated and spread efficiently after transfection and subsequent infection of naive Huh7.5 cells, reaching titers of 10(3.5) and 10(4.4) FFU/ml, respectively. IMPORTANCE Hepatitis C virus (HCV) was discovered in 1989 with the cloning of the prototype strain HCV-1 genome. In 1997, two molecular clones of H77, the other HCV prototype strain, were shown to be infectious in chimpanzees, but not in vitro. HCV research was hampered by a lack of infectious cell culture systems, which became available only in 2005 with the discovery of JFH1 (genotype 2a), a genome that could establish infection in Huh7.5 cells. Recently, we developed in vitro infectious clones for genotype 1a (TN), 2a (J6), and 2b (J8, DH8, and DH10) strains by identifying key adaptive mutations. Globally, genotype 1 is the most prevalent. Studies using HCV-1 and H77 prototype sequences have generated important knowledge on HCV. Thus, the in vitro infectious clones developed here for these 1a strains will be of particular value in advancing HCV research. Moreover, our findings open new avenues for the culture adaptation of HCV isolates of different genotypes.
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Li YP, Ramirez S, Humes D, Jensen SB, Gottwein JM, Bukh J. Differential sensitivity of 5'UTR-NS5A recombinants of hepatitis C virus genotypes 1-6 to protease and NS5A inhibitors. Gastroenterology 2014; 146:812-821.e4. [PMID: 24262279 DOI: 10.1053/j.gastro.2013.11.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 10/22/2013] [Accepted: 11/13/2013] [Indexed: 12/29/2022]
Abstract
BACKGROUND & AIMS Hepatitis C virus (HCV) therapy will benefit from the preclinical evaluation of direct-acting antiviral (DAA) agents in infectious culture systems that test the effects on different virus genotypes. We developed HCV recombinants comprising the 5' untranslated region-NS5A (5-5A) from genotypes 1-6 and 2a(JFH1) NS5B-3' untranslated region, and tested the effects of NS3 protease and NS5A inhibitors on these recombinants. METHODS The HCV 5-5A recombinants with previously identified mutations in the NS3-helicase (F1464L), NS4A (A1672S), and NS5B (D2979G) were adapted and improved, by incorporating additional recovered mutations that increased their propagation in Huh7.5 cells. Concentration-response profiles were determined for each DAA agent in replicate infected Huh7.5 cells. RESULTS Developed efficient 1a(H77), 1a(TN), 3a(S52), 4a(ED43), 5a(SA13), and 6a(HK6a) 5-5A recombinants did not require mutations after viral passage in the NS3 protease or NS5A domain-I regions targeted by the drugs. They were inhibited in a concentration-dependent manner by the NS3 protease inhibitors telaprevir, boceprevir, asunaprevir, simeprevir, vaniprevir, faldaprevir, and MK-5172 and by the NS5A inhibitor daclatasvir. The 1a(TN) 5-5A and JFH1-independent full-length viruses had similar levels of sensitivity to the DAA agents, validating the 5-5A recombinants as surrogates for full-length viruses in DAA testing. Compared with the 1a(TN) full-length virus, the 3a(S52) 5-5A recombinant was highly resistant to all protease inhibitors, and the 4a(ED43) recombinant was highly resistant to telaprevir and boceprevir, but most sensitive to other protease inhibitors. Compared with other protease inhibitors, MK-5172 had exceptional potency against all HCV genotypes. The NS5A inhibitor daclatasvir had the highest potency observed, but with genotype-dependent activity. CONCLUSIONS The mutations F1464L, A1672S, and D2979G permitted the development of efficient HCV recombinants comprising genotype-specific 5' untranslated region-NS5A (5-5A), which include the natural NS3 protease and NS5A domain-I drug targets. The robust replication of adapted 5-5A recombinants allowed for direct comparison of NS3 protease and NS5A inhibitors against HCV strains of genotypes 1-6.
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Affiliation(s)
- Yi-Ping Li
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Santseharay Ramirez
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Daryl Humes
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sanne B Jensen
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Judith M Gottwein
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Hvidovre Hospital and Department of International Health, 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 and Clinical Research Centre, Hvidovre Hospital and Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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A novel strategy to develop a robust infectious hepatitis C virus cell culture system directly from a clinical isolate. J Virol 2013; 88:1484-91. [PMID: 24227861 DOI: 10.1128/jvi.02929-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Hepatitis C virus (HCV) infection is a leading cause of chronic liver diseases. Progress in the HCV field was greatly enhanced by constructing infectious cDNA clone of JFH-1. Since then, JFH-1-based intra- and intergenotypic recombinants have been developed, and this permitted the study of vaccines and antiviral inhibitors for all genotypes. Recently, highly efficient HCV culture systems have been established by using consensus sequence-based clones. We developed a novel strategy to construct infectious HCV cDNA clone by combining functional screening of sequences directly from a genotype 2a clinical isolate (PR63) and cell culture adaptation. Using JFH-1 cDNA as the starting backbone, we sequentially replaced the JFH-1 fragments with a sequence from the pools of PR63 sequences. Through engineering adaptive mutations that improve HCV infectivity, we finally established a full-length cell culture-derived infectious clone of PR63, named PR63cc, that could efficiently produce virus particles in Huh7-derived cells, with peak titers of 1.6 × 10(5) focus-forming units/ml. The PR63cc could be neutralized by an anti-E2 antibody and inhibited by antiviral agents but appeared more resistant to an NS5A inhibitor than JFH-1. In summary, we developed a new approach to construct an infectious HCV cDNA clone that can produce viruses efficiently in cell culture. This approach could be applied to other viral isolates, with potential implications for individualized treatments of HCV patients.
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Hepatitis C virus RNA replication and virus particle assembly require specific dimerization of the NS4A protein transmembrane domain. J Virol 2013; 88:628-42. [PMID: 24173222 DOI: 10.1128/jvi.02052-13] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Hepatitis C virus (HCV) NS4A is a single-pass transmembrane (TM) protein essential for viral replication and particle assembly. The sequence of the NS4A TM domain is highly conserved, suggesting that it may be important for protein-protein interactions. To test this hypothesis, we measured the potential dimerization of the NS4A TM domain in a well-characterized two-hybrid TM protein interaction system. The NS4A TM domain exhibited a strong homotypic interaction that was comparable in affinity to glycophorin A, a well-studied human blood group antigen that forms TM homodimers. Several mutations predicted to cluster on a common surface of the NS4A TM helix caused significant reductions in dimerization, suggesting that these residues form an interface for NS4A dimerization. Mutations in the NS4A TM domain were further examined in the JFH-1 genotype 2a replicon system; importantly, all mutations that destabilized NS4A dimers also caused defects in RNA replication and/or virus assembly. Computational modeling of NS4A TM interactions suggests a right-handed dimeric interaction of helices with an interface that is consistent with the mutational effects. Furthermore, defects in NS4A oligomerization and virus particle assembly of two mutants were rescued by NS4A A15S, a TM mutation recently identified through forward genetics as a cell culture-adaptive mutation. Together, these data provide the first example of a functionally important TM dimer interface within an HCV nonstructural protein and reveal a fundamental role of the NS4A TM domain in coordinating HCV RNA replication and virus particle assembly.
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Adapted J6/JFH1-based Hepatitis C virus recombinants with genotype-specific NS4A show similar efficacies against lead protease inhibitors, alpha interferon, and a putative NS4A inhibitor. Antimicrob Agents Chemother 2013; 57:6034-49. [PMID: 24060868 DOI: 10.1128/aac.01176-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
To facilitate studies of hepatitis C virus (HCV) NS4A, we aimed at developing J6/JFH1-based recombinants with genotype 1- to 7-specific NS4A proteins. We developed efficient culture systems expressing NS4A proteins of genotypes (isolates) 1a (H77 and TN), 1b (J4), 2a (J6), 4a (ED43), 5a (SA13), 6a (HK6a), and 7a (QC69), with peak infectivity titers of ∼3.5 to 4.5 log10 focus-forming units per ml. Except for genotype 2a (J6), growth depended on adaptive mutations identified in long-term culture. Genotype 1a, 1b, and 4a recombinants were adapted by amino acid substitutions F772S (p7) and V1663A (NS4A), while 5a, 6a, and 7a recombinants required additional substitutions in the NS3 protease and/or NS4A. We demonstrated applicability of the developed recombinants for study of antivirals. Genotype 1 to 7 NS4A recombinants showed similar responses to the protease inhibitors telaprevir (VX-950), boceprevir (Sch503034), simeprevir (TMC435350), danoprevir (ITMN-191), and vaniprevir (MK-7009), to alpha interferon 2b, and to the putative NS4A inhibitor ACH-806. The efficacy of ACH-806 was lower than that of protease inhibitors and was not influenced by changes at amino acids 1042 and 1065 (in the NS3 protease), which have been suggested to mediate resistance to ACH-806 in replicons. Genotype 1a, 1b, and 2a recombinants showed viral spread under long-term treatment with ACH-806, without acquisition of resistance mutations in the NS3-NS4A region. Relatively high concentrations of ACH-806 inhibited viral assembly, but not replication, in a single-cycle production assay. The developed HCV culture systems will facilitate studies benefitting from expression of genotype-specific NS4A in a constant backbone in the context of the complete viral replication cycle, including functional studies and evaluations of the efficacy of antivirals.
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Lu J, Tao W, Li R, Xiang Y, Zhang N, Xiang X, Xie Q, Zhong J. Construction and characterization of infectious hepatitis C virus chimera containing structural proteins directly from genotype 1b clinical isolates. Virology 2013; 443:80-8. [DOI: 10.1016/j.virol.2013.04.030] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/10/2013] [Accepted: 04/27/2013] [Indexed: 12/17/2022]
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14
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Galli A, Scheel TKH, Prentoe JC, Mikkelsen LS, Gottwein JM, Bukh J. Analysis of hepatitis C virus core/NS5A protein co-localization using novel cell culture systems expressing core-NS2 and NS5A of genotypes 1-7. J Gen Virol 2013; 94:2221-2235. [PMID: 23907394 DOI: 10.1099/vir.0.053868-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Hepatitis C virus (HCV) is an important human pathogen infecting hepatocytes. With the advent of infectious cell culture systems, the HCV particle assembly and release processes are finally being uncovered. The HCV core and NS5A proteins co-localize on cytoplasmic lipid droplets (cLDs) or on the endoplasmic reticulum (ER) at different stages of particle assembly. Current knowledge on assembly and release is primarily based on studies in genotype 2a cell culture systems; however, given the high genetic heterogeneity of HCV, variations might exist among genotypes. Here, we developed novel HCV strain JFH1-based recombinants expressing core-NS2 and NS5A from genotypes 1-7, and analysed core and NS5A co-localization in infected cells. Huh7.5 cells were transfected with RNA of core-NS2/NS5A recombinants and putative adaptive mutations were analysed by reverse genetics. Adapted core-NS2/NS5A recombinants produced infectivity titres of 10(2.5)-10(4.5) f.f.u. ml(-1). Co-localization analysis demonstrated that the core and NS5A proteins from all genotypes co-localized extensively, and there was no significant difference in protein co-localization among genotypes. In addition, we found that the core and NS5A proteins were highly associated with cLDs at 12 h post-infection but became mostly ER associated at later stages. Finally, we found that different genotypes showed varying levels of core/cLD co-localization, with a possible effect on viral assembly/release. In summary, we developed a panel of HCV genotype 1-7 core-NS2/NS5A recombinants producing infectious virus, and an immunostaining protocol detecting the core and NS5A proteins from seven different genotypes. These systems will allow, for the first time, investigation of core/NS5A interactions during assembly and release of HCV particles of all major genotypes.
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Affiliation(s)
- Andrea Galli
- 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 and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - 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 and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jannick C Prentoe
- 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 and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lotte S Mikkelsen
- 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 and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - 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 and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - 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 and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Productive homologous and non-homologous recombination of hepatitis C virus in cell culture. PLoS Pathog 2013; 9:e1003228. [PMID: 23555245 PMCID: PMC3610614 DOI: 10.1371/journal.ppat.1003228] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 01/21/2013] [Indexed: 02/06/2023] Open
Abstract
Genetic recombination is an important mechanism for increasing diversity of RNA viruses, and constitutes a viral escape mechanism to host immune responses and to treatment with antiviral compounds. Although rare, epidemiologically important hepatitis C virus (HCV) recombinants have been reported. In addition, recombination is an important regulatory mechanism of cytopathogenicity for the related pestiviruses. Here we describe recombination of HCV RNA in cell culture leading to production of infectious virus. Initially, hepatoma cells were co-transfected with a replicating JFH1ΔE1E2 genome (genotype 2a) lacking functional envelope genes and strain J6 (2a), which has functional envelope genes but does not replicate in culture. After an initial decrease in the number of HCV positive cells, infection spread after 13–36 days. Sequencing of recovered viruses revealed non-homologous recombinants with J6 sequence from the 5′ end to the NS2–NS3 region followed by JFH1 sequence from Core to the 3′ end. These recombinants carried duplicated sequence of up to 2400 nucleotides. HCV replication was not required for recombination, as recombinants were observed in most experiments even when two replication incompetent genomes were co-transfected. Reverse genetic studies verified the viability of representative recombinants. After serial passage, subsequent recombination events reducing or eliminating the duplicated region were observed for some but not all recombinants. Furthermore, we found that inter-genotypic recombination could occur, but at a lower frequency than intra-genotypic recombination. Productive recombination of attenuated HCV genomes depended on expression of all HCV proteins and tolerated duplicated sequence. In general, no strong site specificity was observed. Non-homologous recombination was observed in most cases, while few homologous events were identified. A better understanding of HCV recombination could help identification of natural recombinants and thereby lead to improved therapy. Our findings suggest mechanisms for occurrence of recombinants observed in patients. Genetic recombination is the alternative joining of nucleic acids leading to novel combinations of genetic information. While DNA recombination in cells is of importance for evolution and adaptive immunity, RNA recombination often has only transient effects. However, RNA viruses are rapidly evolving and recombination can be an important evolutionary step in addition to mutations introduced by the viral polymerase. Recombination can allow escape from the host immune system and from antiviral treatment, and recombination of live attenuated viral vaccines has led to re-emergence of disease. Hepatitis C virus (HCV) is an important human pathogen that chronically infects more than 130 million worldwide and leads to serious liver disease. For HCV, naturally occurring recombinants are rare but clinically important. HCV recombination constitutes a challenge to antiviral treatment and can potentially provide an escape mechanism for the virus. In this study, we established an assay for HCV RNA recombination and characterized the emerging homologous and non-homologous recombinant viruses. Interestingly, recombination did not depend on viral replication, occurred most efficiently between isolates of the same genotype and did not occur with strong site-specificity. Better diagnosis of clinically important recombinants and an increased knowledge on viral recombination could strengthen antiviral and vaccine development.
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Carlsen THR, Scheel TKH, Ramirez S, Foung SKH, Bukh J. Characterization of hepatitis C virus recombinants with chimeric E1/E2 envelope proteins and identification of single amino acids in the E2 stem region important for entry. J Virol 2013; 87:1385-99. [PMID: 23152512 PMCID: PMC3554168 DOI: 10.1128/jvi.00684-12] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2012] [Accepted: 10/30/2012] [Indexed: 02/07/2023] Open
Abstract
The hepatitis C virus (HCV) envelope proteins E1 and E2 play a key role in host cell entry and represent important targets for vaccine and drug development. Here, we characterized HCV recombinants with chimeric E1/E2 complexes in vitro. Using genotype 1a/2a JFH1-based recombinants expressing 1a core-NS2, we exchanged E2 with functional isolate sequences of genotypes 1a (alternative isolate), 1b, and 2a. While the 1a-E2 exchange did not impact virus viability, the 2a-E2 recombinant was nonviable. After E2 exchange from three 1b isolates, long delays were observed before spread of infection. For recovered 1b-E2 recombinants, single E2 stem region amino acid changes were identified at residues 706, 707, and 710. In reverse genetic studies, these mutations increased infectivity titers by ~100-fold, apparently without influencing particle stability or cell binding although introducing slight decrease in particle density. In addition, the 1b-E2 exchange led to a decrease in secreted core protein of 25 to 50%, which was further reduced by the E2 stem region mutations. These findings indicated that compensatory mutations permitted robust infectious virus production, without increasing assembly/release. Studies of E1/E2 heterodimerization showed no differences in intracellular E1/E2 interaction for chimeric constructs with or without E2 stem region mutations. Interestingly, the E2 stem region mutations allowed efficient entry, which was verified in 1a-E1/1b-E2 HCV pseudoparticle assays. A CD81 inhibition assay indicated that the mutations influenced a late step of the HCV entry pathway. Overall, this study identified specific amino acids in the E2 stem region of importance for HCV entry and for production of infectious virus particles.
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Affiliation(s)
- Thomas H. R. Carlsen
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Troels K. H. Scheel
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Santseharay Ramirez
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Steven K. H. Foung
- Department of Pathology, Stanford University School of Medicine, Stanford, California, USA
| | - Jens Bukh
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, and Department of International Health, Immunology, and Microbiology, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
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Combination treatment with hepatitis C virus protease and NS5A inhibitors is effective against recombinant genotype 1a, 2a, and 3a viruses. Antimicrob Agents Chemother 2012; 57:1291-303. [PMID: 23274664 DOI: 10.1128/aac.02164-12] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
With the development of directly acting antivirals, hepatitis C virus (HCV) therapy entered a new era. However, rapid selection of resistance mutations necessitates combination therapy. To study combination therapy in infectious culture systems, we aimed at developing HCV semi-full-length (semi-FL) recombinants relying only on the JFH1 NS3 helicase, NS5B, and the 3' untranslated region. With identified adaptive mutations, semi-FL recombinants of genotypes(isolates) 1a(TN) and 3a(S52) produced supernatant infectivity titers of ~4 log(10) focus-forming units/ml in Huh7.5 cells. Genotype 1a(TN) adaptive mutations allowed generation of 1a(H77) semi-FL virus. Concentration-response profiles revealed the higher efficacy of the NS3 protease inhibitor asunaprevir (BMS-650032) and the NS5A inhibitor daclatasvir (BMS-790052) against 1a(TN and H77) than 3a(S52) viruses. Asunaprevir had intermediate efficacy against previously developed 2a recombinants J6/JFH1 and J6cc. Daclatasvir had intermediate efficacy against J6/JFH1, while low sensitivity was confirmed against J6cc. Using a cross-titration scheme, infected cultures were treated until viral escape or on-treatment virologic suppression occurred. Compared to single-drug treatment, combination treatment with relatively low concentrations of asunaprevir and daclatasvir suppressed infection with all five recombinants. Escaped viruses primarily had substitutions at amino acids in the NS3 protease and NS5A domain I reported to be genotype 1 resistance mutations. Inhibitors showed synergism at drug concentrations reported in vivo. In summary, semi-FL HCV recombinants, including the most advanced reported genotype 3a infectious culture system, permitted genotype-specific analysis of combination treatment in the context of the complete viral life cycle. Despite differential sensitivity to lead compound NS3 protease and NS5A inhibitors, genotype 1a, 2a, and 3a viruses were suppressed by combination treatment with relatively low concentrations.
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Highly efficient full-length hepatitis C virus genotype 1 (strain TN) infectious culture system. Proc Natl Acad Sci U S A 2012; 109:19757-62. [PMID: 23151512 DOI: 10.1073/pnas.1218260109] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Chronic infection with hepatitis C virus (HCV) is an important cause of end stage liver disease worldwide. In the United States, most HCV-related disease is associated with genotype 1 infection, which remains difficult to treat. Drug and vaccine development was hampered by inability to culture patient isolates representing HCV genotypes 1-7 and subtypes; only a recombinant 2a genome (strain JFH1) spontaneously replicated in vitro. Recently, we identified three mutations F1464L/A1672S/D2979G (LSG) in the nonstructural (NS) proteins, essential for development of full-length HCV 2a (J6) and 2b (J8) culture systems in Huh7.5 cells. Here, we developed a highly efficient genotype 1a (strain TN) full-length culture system. We initially found that the LSG substitutions conferred viability to an intergenotypic recombinant composed of TN 5' untranslated region (5'UTR)-NS5A and JFH1 NS5B-3'UTR; recovered viruses acquired two adaptive mutations located in NS3 and NS4B. Introduction of these changes into a replication-deficient TN full-length genome, harboring LSG, permitted efficient HCV production. Additional identified NS4B and NS5B mutations fully adapted the TN full-length virus. Thus, a TN genome with 8 changes (designated TN cell-culture derived, TNcc) replicated efficiently and released infectious particles of ∼5 log(10) focus-forming units per mL; passaged TNcc did not require additional changes. IFN-α and directly acting antivirals targeting the HCV protease, NS5A, and NS5B, each inhibited full-length TN infection dose-dependently. Given the unique importance of genotype 1 for pathogenesis, this infectious 1a culture system represents an important advance in HCV research. The approach used and the mutations identified might permit culture development for other HCV isolates, thus facilitating vaccine development and personalized treatment.
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Bukh J. Animal models for the study of hepatitis C virus infection and related liver disease. Gastroenterology 2012; 142:1279-1287.e3. [PMID: 22537434 DOI: 10.1053/j.gastro.2012.02.016] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Revised: 02/09/2012] [Accepted: 02/15/2012] [Indexed: 12/15/2022]
Abstract
Hepatitis C virus (HCV) causes liver-related death in more than 300,000 people annually. Treatments for patients with chronic HCV are suboptimal, despite the introduction of directly acting antiviral agents. There is no vaccine that prevents HCV infection. Relevant animal models are important for HCV research and development of drugs and vaccines. Chimpanzees are the best model for studies of HCV infection and related innate and adaptive host immune responses. They can be used in immunogenicity and efficacy studies of HCV vaccines. The only small animal models of robust HCV infection are T- and B- cell deficient mice with human chimeric livers. Although these mice cannot be used in studies of adaptive immunity, they have provided new insights into HCV neutralization, interactions between virus and receptors, innate host responses, and therapeutic approaches. Recent progress in developing genetically humanized mice is exciting, but these models only permit studies of specific steps in the HCV life cycle and have limited or no viral replication.
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Affiliation(s)
- Jens Bukh
- Copenhagen Hepatitis C Program (CO-HEP), Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark
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20
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Abstract
The reality of hepatitis C is inescapable for the estimated 130 million people worldwide chronically infected with the virus. Yet this pathogen has been notoriously difficult to move from the infected individual into experimental systems, and each advance--from the identification of the infectious agent to its culture and study--has been a significant challenge. As a result of unrelenting technical hurdles, preventative and therapeutic options have been slow to reach hepatitis C patients. More than 35 years since the recognition of the disease, there is no vaccine available, and the only approved treatment, a combination of pegylated interferon-alpha (IFN-α) and ribavirin, is frequently ineffective. Decades of research, however, have resulted in systematic progress and much is now known about this once elusive pathogen. Most importantly, key breakthroughs have stimulated drug discovery, and the first generation of specifically targeted antiviral inhibitors is poised to enter the market. This review provides a look back at progress in developing tractable model systems for this important agent of chronic hepatitis.
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Affiliation(s)
- Catherine L Murray
- The Center for the Study of Hepatitis C, The Rockefeller University, New York, New York 10065, USA.
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Li YP, Ramirez S, Gottwein JM, Bukh J. Non-genotype-specific role of the hepatitis C virus 5' untranslated region in virus production and in inhibition by interferon. Virology 2011; 421:222-34. [PMID: 22029937 DOI: 10.1016/j.virol.2011.10.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 06/15/2011] [Accepted: 10/03/2011] [Indexed: 12/18/2022]
Abstract
The 5' untranslated region (5'UTR) of hepatitis C virus (HCV) is structured into four domains (I-IV) with numerous genotype-specific nucleotides. It is unknown whether the polymorphisms confer genotype-specific functions to the 5'UTR. Using viable JFH1-based Core-NS2 recombinants, we developed and characterized HCV genotypes 1-7 recombinants with highly diverse 5'UTRs (genotypes 1a and 3a), 2a recombinants (J6/JFH1) with 5'UTR of genotypes 1-6 or with heterotypic chimeric (1a/3a and 3a/1a) 5'UTR domains I, II or III, and 1a recombinants with 5'UTR domain I of genotypes 1-6. All were fully functional in Huh7.5 cells; therefore, the 5'UTR apparently functions in a non-genotype-specific manner in HCV production in vitro. However, adenine at the 5'-terminus was required. We demonstrated that J6/JFH1 with 5'UTR of genotypes 1-6 responded similarly to interferon-α2b. This study provides novel insight into the role of the 5'UTR in the HCV life cycle and facilitates HCV basic research and testing of 5'UTR-targeting antivirals.
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Affiliation(s)
- Yi-Ping Li
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark
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Scheel TKH, Gottwein JM, Mikkelsen LS, Jensen TB, Bukh J. Recombinant HCV variants with NS5A from genotypes 1-7 have different sensitivities to an NS5A inhibitor but not interferon-α. Gastroenterology 2011; 140:1032-42. [PMID: 21111742 DOI: 10.1053/j.gastro.2010.11.036] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2010] [Revised: 10/16/2010] [Accepted: 11/10/2010] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Heterogeneity in the hepatitis C virus (HCV) protein NS5A influences its sensitivity to interferon-based therapy. Furthermore, NS5A is an important target for development of HCV-specific inhibitors. We aimed to develop recombinant infectious cell culture systems that express NS5A from isolates of the 7 major HCV genotypes, and determining their sensitivity to a specific NS5A inhibitor and to interferon-α. METHODS Huh7.5 hepatoma cells were transfected with RNA of genotype 1-7 NS5A recombinants. Viability was determined by measuring HCV replication and infectivity titers. Putative adaptive mutations were analyzed by reverse genetics. The activity of antiviral agents was determined in high-throughput infection assays. RESULTS Cells infected with viable HCV that expressed NS5A of genotypes 1-7 produced relatively high viral titers; most NS5A recombinants required introduction of specific adaptive mutations. The efficacy of the NS5A inhibitor BMS-790052 varied greatly, based on NS5A isolate, with median effective concentration (EC(50)) values ranging from 0.009 nmol/L to 14 nmol/L; the high sensitivity of genotype 1b NS5A to BMS-790052 reflected observations from clinical studies. Specific residues in NS5A domain I were associated with >100-fold variations in sensitivity between isolates of the same HCV subtype. The Y/T2065H mutation conferred resistance to BMS-790052 that varied among NS5A isolates. When infected cultures were incubated with interferon-α, all NS5A recombinants had EC(50) values of ∼0.2 IU/mL, including an NS5A genotype 1b mutant with a putative sensitive-type, interferon sensitivity determining region. CONCLUSIONS We developed efficient in vitro systems in which recombinant viruses express HCV genotypes 1-7 NS5A; these permit genotype- and isolate-specific analyses of NS5A and the effects of antiviral compounds and resistance mutations. These culture systems will facilitate development of specific inhibitors against NS5A of different HCV variants.
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Affiliation(s)
- Troels K H Scheel
- Copenhagen Hepatitis C Program, Department of Infectious Diseases and Clinical Research Centre, Copenhagen University Hospital, Hvidovre, Denmark
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Scheel TKH, Gottwein JM, Carlsen THR, Li YP, Jensen TB, Spengler U, Weis N, Bukh J. Efficient culture adaptation of hepatitis C virus recombinants with genotype-specific core-NS2 by using previously identified mutations. J Virol 2011; 85:2891-906. [PMID: 21177811 PMCID: PMC3067958 DOI: 10.1128/jvi.01605-10] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Accepted: 12/09/2010] [Indexed: 12/29/2022] Open
Abstract
Hepatitis C virus (HCV) is an important cause of chronic liver disease, and interferon-based therapy cures only 40 to 80% of patients, depending on HCV genotype. Research was accelerated by genotype 2a (strain JFH1) infectious cell culture systems. We previously developed viable JFH1-based recombinants encoding the structural proteins (core, E1, E2), p7, and NS2 of prototype isolates of the seven major HCV genotypes; most recombinants required adaptive mutations. To enable genotype-, subtype-, and isolate-specific studies, we developed efficient core-NS2 recombinants from additional genotype 1a (HC-TN and DH6), 1b (DH1 and DH5), and 3a (DBN) isolates, using previously identified adaptive mutations. Introduction of mutations from isolates of the same subtype either led to immediate efficient virus production or accelerated culture adaptation. The DH6 and DH5 recombinants without introduced mutations did not adapt to culture. Universal adaptive effects of mutations in NS3 (Q1247L, I1312V, K1398Q, R1408W, and Q1496L) and NS5A (V2418L) were investigated for JFH1-based genotype 1 to 5 core-NS2 recombinants; several mutations conferred adaptation to H77C (1a), J4 (1b), S52 (3a), and SA13 (5a) but not to ED43 (4a). The mutations permitting robust virus production in Huh7.5 cells had no apparent effect on viral replication but allowed efficient assembly of intracellular infectious HCV for adapted novel or previously developed recombinants. In conclusion, previously identified mutations permitted development of novel HCV core-NS2 genotype recombinants. Mutations adapting several recombinants to culture were identified, but no mutations were universally adaptive across genotypes. This work provides tools for analysis of HCV genotype specificity and may promote the understanding of genotype-specific patterns in HCV disease and control.
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Affiliation(s)
- 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, Department of Internal Medicine 1, University of Bonn, Bonn, Germany, Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
| | - 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, Department of Internal Medicine 1, University of Bonn, Bonn, Germany, Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
| | - Thomas H. R. Carlsen
- 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, Department of Internal Medicine 1, University of Bonn, Bonn, Germany, Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
| | - 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, Department of Internal Medicine 1, University of Bonn, Bonn, Germany, Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
| | - Tanja B. Jensen
- 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, Department of Internal Medicine 1, University of Bonn, Bonn, Germany, Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
| | - Ulrich Spengler
- 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, Department of Internal Medicine 1, University of Bonn, Bonn, Germany, Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
| | - Nina Weis
- 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, Department of Internal Medicine 1, University of Bonn, Bonn, Germany, Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
| | - 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, Department of Internal Medicine 1, University of Bonn, Bonn, Germany, Department of Infectious Diseases, Copenhagen University Hospital, Hvidovre, Denmark
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Bailey J. An assessment of the use of chimpanzees in hepatitis C research past, present and future: 1. Validity of the chimpanzee model. Altern Lab Anim 2011; 38:387-418. [PMID: 21105756 DOI: 10.1177/026119291003800501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The USA is the only significant user of chimpanzees in biomedical research in the world, since many countries have banned or limited the practice due to substantial ethical, economic and scientific concerns. Advocates of chimpanzee use cite hepatitis C research as a major reason for its necessity and continuation, in spite of supporting evidence that is scant and often anecdotal. This paper examines the scientific and ethical issues surrounding chimpanzee hepatitis C research, and concludes that claims of the necessity of chimpanzees in historical and future hepatitis C research are exaggerated and unjustifiable, respectively. The chimpanzee model has several major scientific, ethical, economic and practical caveats. It has made a relatively negligible contribution to knowledge of, and tangible progress against, the hepatitis C virus compared to non-chimpanzee research, and must be considered scientifically redundant, given the array of alternative methods of inquiry now available. The continuation of chimpanzee use in hepatitis C research adversely affects scientific progress, as well as chimpanzees and humans in need of treatment. Unfounded claims of its necessity should not discourage changes in public policy regarding the use of chimpanzees in US laboratories.
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Affiliation(s)
- Jarrod Bailey
- New England Anti-Vivisection Society, Boston, MA 02108-5100, USA.
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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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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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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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Takikawa S, Engle RE, Faulk KN, Emerson SU, Purcell RH, Bukh J. Molecular evolution of GB virus B hepatitis virus during acute resolving and persistent infections in experimentally infected tamarins. J Gen Virol 2009; 91:727-33. [PMID: 19906942 DOI: 10.1099/vir.0.015750-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
GB virus B (GBV-B) causes acute hepatitis in experimentally infected tamarins. We compared evolutionary features in acute resolving and persistent GBV-B infection. We detected no evidence of evolution in four animals with clearance during weeks 9-12, whereas three animals with clearance during weeks 13-26 had several substitutions in their polyprotein sequence. A single tamarin had long-term GBV-B viraemia; analysis of virus recovered at weeks 2, 5, 12, 20, 26, 52 and 104 demonstrated that mutations accumulated over time. Overall, the amino acid substitution rate was 3.5x10(-3) and 1.1x10(-3) substitutions per site year(-1) during weeks 1-52 and 53-104, respectively. Thus, there was a significant decrease in evolution over time, as found for hepatitis C virus. The rate of non-synonymous substitution per non-synonymous site compared with that of synonymous substitution per synonymous site decreased over time, suggesting reduction of positive selective pressure. These data demonstrate that prolonged GBV-B infection is associated with viral evolution.
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Affiliation(s)
- Shingo Takikawa
- Hepatitis Viruses and Molecular Hepatitis Sections, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
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Abstract
BACKGROUND Chimpanzees have been widely used in hepatitis C virus (HCV) research, but their endangered status and high financial and ethical costs have prompted a closer review. METHODS One hundred and nine articles published in 1998-2007 were analyzed for the number of chimpanzees involved, experimental procedures, objectives and other relevant issues. RESULTS The articles described the use of 852 chimpanzees, but accounting for likely multiple uses, the number of individual chimpanzees involved here is estimated to be approximately 500. Most articles addressed immunology and inoculation studies. A significant portion of studies lasted for several months or years. Approximately one half of the individual chimpanzees were each used in 2-10 studies. CONCLUSIONS Significant financial and scientific resources have been expended in these chimpanzee HCV studies. Discussion addresses troublesome questions presented by some of the reviewed articles, including statistical validity, repeatability, and biological relevance of this model. These concerns merit attention as future approaches to HCV research and research priorities are considered.
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Pournaghi-Azar M, Ahour F, Hejazi M. Differential Pulse Voltammetric Detection of Hepatitis C Virus 1a Oligonucleotide Chain by a Label-Free Electrochemical DNA Hybridization Biosensor Using Consensus Sequence of Hepatitis C Virus 1a Probe on the Pencil Graphite Electrode. ELECTROANAL 2009. [DOI: 10.1002/elan.200804570] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Human immune memory to yellow fever and smallpox vaccination. J Clin Immunol 2008; 29:151-7. [PMID: 19052852 DOI: 10.1007/s10875-008-9267-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 11/17/2008] [Indexed: 12/24/2022]
Abstract
BACKGROUND Establishment of immunological memory is a hallmark of adaptive immune responses and the biological mechanism for the success of vaccines. However, in humans, much of our knowledge about adaptive immune responses derives from studies of chronic viral infections. OBJECTIVE Here, we summarize the work of our laboratory and others on B and T cell responses and the establishment and maintenance of immune memory after acute viral infections induced by vaccination with two of the most successful vaccines to date, the yellow fever and the smallpox vaccines.
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Kato T, Choi Y, Elmowalid G, Sapp RK, Barth H, Furusaka A, Mishiro S, Wakita T, Krawczynski K, Liang TJ. Hepatitis C virus JFH-1 strain infection in chimpanzees is associated with low pathogenicity and emergence of an adaptive mutation. Hepatology 2008; 48:732-40. [PMID: 18712792 PMCID: PMC2535917 DOI: 10.1002/hep.22422] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
UNLABELLED The identification of the hepatitis C virus (HCV) strain JFH-1 enabled the successful development of infectious cell culture systems. Although this strain replicates efficiently and produces infectious virus in cell culture, the replication capacity and pathogenesis in vivo are still undefined. To assess the in vivo phenotype of the JFH-1 virus, cell culture-generated JFH-1 virus (JFH-1cc) and patient serum from which JFH-1 was isolated were inoculated into chimpanzees. Both animals became HCV RNA-positive 3 days after inoculation but showed low-level viremia and no evidence of hepatitis. HCV viremia persisted 8 and 34 weeks in JFH-1cc and patient serum-infected chimpanzees, respectively. Immunological analysis revealed that HCV-specific immune responses were similarly induced in both animals. Sequencing of HCV at various times of infection indicated more substitutions in the patient serum-inoculated chimpanzee, and the higher level of sequence variations seemed to be associated with a prolonged infection in this animal. A common mutation G838R in the NS2 region emerged early in both chimpanzees. This mutation enhances viral assembly, leading to an increase in viral production in transfected or infected cells. CONCLUSION Our study shows that the HCV JFH-1 strain causes attenuated infection and low pathogenicity in chimpanzees and is capable of adapting in vivo with a unique mutation conferring an enhanced replicative phenotype.
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Affiliation(s)
- Takanobu Kato
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD. 20892, USA,Department of Medical Sciences, Toshiba General Hospital, Shinagawa, Tokyo, 140-8522, Japan,Department of Virology II, National Institute of Infectious Diseases, Shinjuku, Tokyo, 162-8640, Japan
| | - Youkyung Choi
- Division of Viral Hepatitis, Center for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - Gamal Elmowalid
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD. 20892, USA
| | - Ronda K. Sapp
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD. 20892, USA
| | - Heidi Barth
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD. 20892, USA
| | - Akihiro Furusaka
- Department of Internal Medicine, Jikei University School of Medicine (Daisan), Komae, Tokyo, 201-8601, Japan
| | - Shunji Mishiro
- Department of Medical Sciences, Toshiba General Hospital, Shinagawa, Tokyo, 140-8522, Japan
| | - Takaji Wakita
- Department of Virology II, National Institute of Infectious Diseases, Shinjuku, Tokyo, 162-8640, Japan
| | - Krzysztof Krawczynski
- Division of Viral Hepatitis, Center for Disease Control and Prevention, Atlanta, GA 30333, USA
| | - T. Jake Liang
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD. 20892, USA
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Gottwein JM, Bukh J. Cutting the gordian knot-development and biological relevance of hepatitis C virus cell culture systems. Adv Virus Res 2008; 71:51-133. [PMID: 18585527 DOI: 10.1016/s0065-3527(08)00002-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Worldwide approximately 180 million people are chronically infected with hepatitis C virus (HCV). HCV isolates exhibit extensive genetic heterogeneity and have been grouped in six genotypes and various subtypes. Additionally, several naturally occurring intergenotypic recombinants have been described. Research on the viral life cycle, efficient therapeutics, and a vaccine has been hampered by the absence of suitable cell culture systems. The first system permitting studies of the full viral life cycle was intrahepatic transfection of RNA transcripts of HCV consensus complementary DNA (cDNA) clones into chimpanzees. However, such full-length clones were not infectious in vitro. The development of the replicon system and HCV pseudo-particles allowed in vitro studies of certain aspects of the viral life cycle, RNA replication, and viral entry, respectively. Identification of the genotype 2 isolate JFH1, which for unknown reasons showed an exceptional replication capability and resulted in formation of infectious viral particles in the human hepatoma cell line Huh7, led in 2005 to the development of the first full viral life cycle in vitro systems. JFH1-based systems now enable in vitro studies of the function of viral proteins, their interaction with each other and host proteins, new antivirals, and neutralizing antibodies in the context of the full viral life cycle. However, several challenges remain, including development of cell culture systems for all major HCV genotypes and identification of other susceptible cell lines.
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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, Denmark
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Bukh J, Thimme R, Meunier JC, Faulk K, Spangenberg HC, Chang KM, Satterfield W, Chisari FV, Purcell RH. Previously infected chimpanzees are not consistently protected against reinfection or persistent infection after reexposure to the identical hepatitis C virus strain. J Virol 2008; 82:8183-95. [PMID: 18550671 PMCID: PMC2519567 DOI: 10.1128/jvi.00142-08] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Accepted: 05/31/2008] [Indexed: 12/18/2022] Open
Abstract
Protective immunity after resolved hepatitis C virus (HCV) infection has been reported. However, the breadth of this immunity has remained controversial, and the role of neutralizing antibodies has not been well-defined. In the present study, two chimpanzees (CH96A008 and CH1494) with resolved monoclonal H77C (genotype 1a) infection were rechallenged with low-dose homologous H77C virus about 12 months after viral clearance; CH96A008 became persistently infected, and CH1494 had transient viremia lasting 2 weeks. CH1494 was subsequently either partially or completely protected following five homologous rechallenges with monoclonal H77C or polyclonal H77 and after six heterologous rechallenges with HC-J4 (genotype 1b) or HC-J6 (genotype 2a) viruses. Subsequently, a final challenge with H77C resulted in persistent HCV infection. In both chimpanzees, serum neutralizing antibodies against retroviral pseudoparticles bearing the H77C envelope proteins were not detected during the initial infection or during rechallenge. However, anamnestic cellular immune responses developed during the initial homologous rechallenge, in particular in CH96A008, which developed a persistent infection. Polyprotein sequences of viruses recovered from CH1494 after the two homologous rechallenges that resulted in transient viremia were identical with the H77C virus. In contrast, the polyprotein sequences of viruses recovered from both chimpanzees after homologous rechallenge resulting in persistent infection had numerous changes. These findings have important implications for our understanding of immunity against HCV; even in the best-case scenario with autologous rechallenge, low-level viral persistence was seen in the presence of primed T-cell responses.
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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, Building 50, Room 6531, 50 South Dr., MSC 8009, Bethesda, MD 20892-8009, USA.
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Vanwolleghem T, Bukh J, Meuleman P, Desombere I, Meunier JC, Alter H, Purcell RH, Leroux-Roels G. Polyclonal immunoglobulins from a chronic hepatitis C virus patient protect human liver-chimeric mice from infection with a homologous hepatitis C virus strain. Hepatology 2008; 47:1846-55. [PMID: 18452146 DOI: 10.1002/hep.22244] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
UNLABELLED The role of the humoral immune response in the natural course of hepatitis C virus (HCV) infection is widely debated. Most chronically infected patients have immunoglobulin G (IgG) antibodies capable of neutralizing HCV pseudoparticles (HCVpp) in vitro. It is, however, not clear whether these IgG can prevent a de novo HCV infection in vivo and contribute to the control of viremia in infected individuals. We addressed this question with homologous in vivo protection studies in human liver-urokinase-type plasminogen activator (uPA)(+/+) severe combined immune deficient (SCID) mice. Chimeric mice were loaded with chronic phase polyclonal IgG and challenged 3 days later with a 100% infectious dose of the acute phase H77C virus, both originating from patient H. Passive immunization induced sterilizing immunity in five of eight challenged animals. In the three nonprotected animals, the HCV infection was attenuated, as evidenced by altered viral kinetics in comparison with five control IgG-treated animals. Plasma samples obtained from the mice at viral challenge neutralized H77C-HCVpp at dilutions as high as 1/400. Infection was completely prevented when, before administration to naïve chimeric mice, the inoculum was pre-incubated in vitro at an IgG concentration normally observed in humans. CONCLUSION Polyclonal IgG from a patient with a long-standing HCV infection not only displays neutralizing activity in vitro using the HCVpp system, but also conveys sterilizing immunity toward the ancestral HCV strain in vivo, using the human liver-chimeric mouse model. Both experimental systems will be useful tools to identify neutralizing antibodies for future clinical use.
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Miller JD, van der Most RG, Akondy RS, Glidewell JT, Albott S, Masopust D, Murali-Krishna K, Mahar PL, Edupuganti S, Lalor S, Germon S, Del Rio C, Mulligan MJ, Staprans SI, Altman JD, Feinberg MB, Ahmed R. Human effector and memory CD8+ T cell responses to smallpox and yellow fever vaccines. Immunity 2008; 28:710-22. [PMID: 18468462 DOI: 10.1016/j.immuni.2008.02.020] [Citation(s) in RCA: 461] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Revised: 02/25/2008] [Accepted: 02/28/2008] [Indexed: 12/11/2022]
Abstract
To explore the human T cell response to acute viral infection, we performed a longitudinal analysis of CD8(+) T cells responding to the live yellow fever virus and smallpox vaccines--two highly successful human vaccines. Our results show that both vaccines generated a brisk primary effector CD8(+) T cell response of substantial magnitude that could be readily quantitated with a simple set of four phenotypic markers. Secondly, the vaccine-induced T cell response was highly specific with minimal bystander effects. Thirdly, virus-specific CD8(+) T cells passed through an obligate effector phase, contracted more than 90% and gradually differentiated into long-lived memory cells. Finally, these memory cells were highly functional and underwent a memory differentiation program distinct from that described for human CD8(+) T cells specific for persistent viruses. These results provide a benchmark for CD8(+) T cell responses induced by two of the most effective vaccines ever developed.
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Affiliation(s)
- Joseph D Miller
- Emory Vaccine Center and the Hope Clinic, Emory University School of Medicine, Atlanta, GA 30322, USA
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Mateu G, Donis RO, Wakita T, Bukh J, Grakoui A. Intragenotypic JFH1 based recombinant hepatitis C virus produces high levels of infectious particles but causes increased cell death. Virology 2008; 376:397-407. [PMID: 18455749 DOI: 10.1016/j.virol.2008.03.027] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2008] [Revised: 02/29/2008] [Accepted: 03/24/2008] [Indexed: 01/22/2023]
Abstract
The full-length hepatitis C virus (HCV) JFH1 genome (genotype 2a) produces moderate titers of infectious particles in cell culture but the optimal determinants required for virion production are unclear. It has been shown that intragenotypic recombinants encoding core to NS2 from J6CF in the context of JFH1 are more robust in the release of viral particles. To understand the contributions of structural and nonstructural genes to HCV replication potential and infectivity, we have characterized intragenotypic recombinant genotype 2a viruses with different portions of the J6 isolate engineered into the JFH1 infectious clone. All genomes produced high levels of intracellular HCV RNA and NS3 protein in Huh-7.5 transfected cells. However, JFH1 genomes containing J6 sequences from C to E2 (CE2) or C to p7 (Cp7) secreted up to 100-fold more infectious HCV particles than the parental JFH1 clone. Subsequent infection of naive Huh-7.5 cells with each of the J6/JFH1 recombinants at a multiplicity of infection of 0.0003 resulted in high viral titers only for CE2 and Cp7 viruses. Comparison of virion production by the Cp7 J6/JFH1 recombinant to previously described J6/JFH1 recombinants showed flexibility of the chimeric junction. Moreover, NTRNS2 a chimeric virus equivalent to the previously reported FL-J6/JFH chimera, showed a 10-fold enhancement of virus titers compared to CNS2. NTRNS2 differs from CNS2 by three nucleotide differences residing in the 5' NTR and core coding sequence and all three nucleotide changes were necessary for increased virion production. Importantly, cells producing Cp7 virus showed increased apoptosis compared with JFH1, an effect correlating with virion production. These studies begin to unravel requirements for robust virus replication and the relationship between increased virion production and host cell viability.
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Affiliation(s)
- Guaniri Mateu
- Department of Medicine, Division of Infectious Diseases, Emory University School of Medicine, Atlanta, GA 30329, USA
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Engle RE, Russell RS, Purcell RH, Bukh J. Development of a TaqMan assay for the six major genotypes of hepatitis C virus: comparison with commercial assays. J Med Virol 2008; 80:72-9. [PMID: 18041021 DOI: 10.1002/jmv.21043] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A quantitative real-time PCR assay was developed that detects genomic RNA from reference strains representing the six major genotypes of hepatitis C virus (HCV) with equal sensitivity and accurately measured HCV RNA in JFH1 HCV-infected Huh7.5 cells. The method is indirectly calibrated to the first international (WHO 96/790) HCV standard preparation and has a linear dynamic range of 10(2.6)-10(6.5) IU/ml. In addition, the inter- and intra-assay precision were approximately 3% CV and <2% CV, respectively. Comparison with results obtained by commercially available HCV RNA Nucleic Acid Technology kits (Versant HCV RNA 3.0 b-DNA and Amplicor HCV Monitor), that also employ the WHO standard, allowed validation of the TaqMan assay against all major HCV genotypes. Both commercial methods detected HCV RNA over a wide dynamic range, but showed a consistent difference of about 0.3 log10 when evaluating samples of different HCV genotypes. The genome titers obtained with the three methods correlated with the infectivity titers previously determined for the HCV reference strains. TaqMan assays have become an essential tool to follow viral load in clinical samples and cell culture-based experiments and this technology offers significant advantages in linear dynamic range, sensitivity and customization.
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Affiliation(s)
- Ronald E Engle
- Hepatitis Viruses Section, Laboratory of Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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Gottwein JM, Scheel TKH, Hoegh AM, Lademann JB, Eugen-Olsen J, Lisby G, Bukh J. Robust hepatitis C genotype 3a cell culture releasing adapted intergenotypic 3a/2a (S52/JFH1) viruses. Gastroenterology 2007; 133:1614-26. [PMID: 17983807 DOI: 10.1053/j.gastro.2007.08.005] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Accepted: 07/19/2007] [Indexed: 01/07/2023]
Abstract
BACKGROUND & AIMS Recently, full viral life cycle hepatitis C virus (HCV) cell culture systems were developed for strain JFH1 (genotype 2a) and an intragenotypic 2a/2a genome (J6/JFH). We aimed at exploiting the unique JFH1 replication characteristics to develop culture systems for genotype 3a, which has a high prevalence worldwide. METHODS Huh7.5 cells were transfected with RNA transcripts of an intergenotypic 3a/JFH1 recombinant with core, E1, E2, p7, and NS2 of the 3a reference strain S52, and released viruses were passaged. Cultures were examined for HCV core and/or NS5A expression (immunostaining), HCV RNA titers (real-time PCR), and infectivity titers (50% tissue culture infectious dose). The role of mutations identified by sequencing of recovered S52/JFH1 viruses was analyzed by reverse genetics studies. RESULTS S52/JFH1 and J6/JFH viruses passaged in Huh7.5 cells showed comparable growth kinetics and similar peak HCV RNA and infectivity titers. However, analysis of S52/JFH1 viruses identified 9 putative adaptive mutations in core, E2, p7, NS3, and NS5A. All 7 S52/JFH1 recombinants with an amino acid change in p7 combined with a change in NS3 or NS5A, but only 2 of 9 recombinants with individual mutations (in p7 and NS3, respectively) were fully viable without the requirement for additional mutations. The biological relevance of our system was shown by studying dependence of 3a/JFH1 infection on CD81, and its impact on distribution of intracellular lipids. CONCLUSIONS We developed a robust intergenotypic recombinant cell culture system for HCV genotype 3a, providing a valuable tool for studies of 3a core-NS2 and related therapeutics.
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Affiliation(s)
- Judith M Gottwein
- Department of Infectious Diseases and Clinical Research Center, Hvidovre, Denmark
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Régeard M, Lepère C, Trotard M, Gripon P, Le Seyec J. Recent contributions of in vitro models to our understanding of hepatitis C virus life cycle. FEBS J 2007; 274:4705-18. [PMID: 17824957 DOI: 10.1111/j.1742-4658.2007.06017.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Hepatitis C virus is a human pathogen responsible for liver diseases including acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma. Its high prevalence, the absence of a prophylactic vaccine and the poor efficiency of current therapies are huge medical problems. Since the discovery of the hepatitis C virus, our knowledge of its biology has been largely punctuated by the development of original models of research. At the end of the 1980s, the chimpanzee model led to cloning of the viral genome and the definition of infectious molecular clones. In 1999, a breakthrough was achieved with the development of a robust in vitro replication model named 'replicon'. This system allowed intensive research into replication mechanisms and drug discovery. Later, in 2003, pseudotyped retroviruses harbouring surface proteins of hepatitis C virus were produced to specifically investigate the viral entry process. It was only in 2005 that infectious viruses were produced in vitro, enabling intensive investigations into the entire life cycle of the hepatitis C virus. This review describes the different in vitro models developed to study hepatitis C virus, their contribution to current knowledge of the virus biology and their future research applications.
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Affiliation(s)
- Morgane Régeard
- INSERM, U522, IFR 140, Hôpital de Pontchaillou, Rennes, France
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