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Miyamura T, Lemon SM, Walker CM, Wakita T. The HCV Replicase Complex and Viral RNA Synthesis. HEPATITIS C VIRUS I 2016. [PMCID: PMC7122888 DOI: 10.1007/978-4-431-56098-2_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Replication of hepatitis C virus (HCV) is tightly linked to membrane alterations designated the membranous web, harboring the viral replicase complex. In this chapter we describe the morphology and 3D architecture of the HCV-induced replication organelles, mainly consisting of double membrane vesicles, which are generated by a concerted action of the nonstructural proteins NS3 to NS5B. Recent studies have furthermore identified a number of host cell proteins and lipids contributing to the biogenesis of the membranous web, which are discussed in this chapter. Viral RNA synthesis is tightly associated with these membrane alterations and mainly driven by the viral RNA dependent RNA polymerase NS5B. We summarize our current knowledge of the structure and function of NS5B, the role of cis-acting replication elements at the termini of the genome in regulating RNA synthesis and the contribution of additional viral and host factors to viral RNA synthesis, which is still ill defined.
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Affiliation(s)
- Tatsuo Miyamura
- National Institute of Infectious Diseases, Tokyo, Tokyo Japan
| | - Stanley M. Lemon
- Departments of Medicine and Microbiology & Immunology , The University of North Carolina, Chapel Hill, North Carolina USA
| | - Christopher M. Walker
- Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio USA
| | - Takaji Wakita
- National Institute of Infectious Diseases, Tokyo, Tokyo Japan
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Pérez-Del-Pulgar S, Gregori J, Rodríguez-Frías F, González P, García-Cehic D, Ramírez S, Casillas R, Domingo E, Esteban JI, Forns X, Quer J. Quasispecies dynamics in hepatitis C liver transplant recipients receiving grafts from hepatitis C virus infected donors. J Gen Virol 2015; 96:3493-3498. [PMID: 26395289 DOI: 10.1099/jgv.0.000289] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The allocation of liver grafts from hepatitis C virus (HCV)-positive donors in HCV-infected liver transplant (LT) recipients leads to infection with two different viral populations. In a previous study, we examined quasispecies dynamics during reinfection by clonal sequencing, which did not allow an accurate characterization of coexistence and competition events. To overcome this limitation, here we used deep-sequencing analysis of a fragment of the HCV NS5B gene in six HCV-infected LT recipients who received HCV-infected grafts. Successive expansions and contractions of quasispecies complexity were observed, evolving in all cases towards a more homogeneous population. The population that became dominant was the one displaying the highest mutant spectrum complexity. In four patients, coexistence of minority mutants, derived from the donor or the recipient, were detected. In conclusion, our study shows that, during reinfection with a different HCV strain in LT recipients, the viral population with the highest diversity always becomes dominant.
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Affiliation(s)
| | - Josep Gregori
- Liver Unit, Lab. Malalties Hepàtiques, Vall d'Hebron Institut de Recerca, Hospital Vall d'Hebron, CIBERehd, Universitat Autònoma de Barcelona, Barcelona, Spain
- Roche Diagnostics, Sant Cugat del Vallès, Barcelona, Spain
| | - Francisco Rodríguez-Frías
- Biochemistry Department, Vall d'Hebron Institut de Recerca, Hospital Vall d'Hebron, CIBERehd, Barcelona, Spain
| | | | - Damir García-Cehic
- Liver Unit, Lab. Malalties Hepàtiques, Vall d'Hebron Institut de Recerca, Hospital Vall d'Hebron, CIBERehd, Universitat Autònoma de Barcelona, Barcelona, Spain
| | | | - Rosario Casillas
- Liver Unit, Lab. Malalties Hepàtiques, Vall d'Hebron Institut de Recerca, Hospital Vall d'Hebron, CIBERehd, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Esteban Domingo
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (CSIC-UAM), Campus de Cantoblanco, CIBERehd, Madrid, Spain
| | - Juan I Esteban
- Liver Unit, Lab. Malalties Hepàtiques, Vall d'Hebron Institut de Recerca, Hospital Vall d'Hebron, CIBERehd, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Xavier Forns
- Liver Unit, Hospital Clínic, IDIBAPS, CIBERehd, Barcelona, Spain
| | - Josep Quer
- Liver Unit, Lab. Malalties Hepàtiques, Vall d'Hebron Institut de Recerca, Hospital Vall d'Hebron, CIBERehd, Universitat Autònoma de Barcelona, Barcelona, Spain
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Pérez-Vilaró G, Fernández-Carrillo C, Mensa L, Miquel R, Sanjuan X, Forns X, Pérez-del-Pulgar S, Díez J. Hepatitis C virus infection inhibits P-body granule formation in human livers. J Hepatol 2015; 62:785-90. [PMID: 25463546 DOI: 10.1016/j.jhep.2014.11.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 10/28/2014] [Accepted: 11/06/2014] [Indexed: 12/04/2022]
Abstract
BACKGROUND & AIMS Decoding the myriad of interactions that hepatitis C virus (HCV) establishes with infected cells is mandatory to obtain a complete understanding of HCV biology and its associated pathogenesis. We and others have previously found that HCV infection disrupts the formation of P-bodies in cell culture. These are cytoplasmic RNA granules with key roles in post-transcriptional regulation of gene expression. Therefore, P-body disruption might have consequences beyond viral propagation. However, whether P-body disruption occurs also in vivo is unknown. Aim of this study was to address this important issue. METHODS Formalin-fixed paraffin-embedded liver biopsies from four groups of patients (healthy donors, patients with non-virus related liver inflammation, HCV- and HBV-infected patients) were immunostained to detect DDX6 and Dcp1, two core P-body components. Changes in the localization of these proteins were assessed by confocal microscopy. RESULTS HCV specifically inhibited P-body formation in hepatocytes from human livers regardless of viral genotype, inflammation grade or whether the infection was recent or long established. Importantly, this alteration was reversed once HCV was eliminated by therapy. Furthermore, we observed in vivo an unexpected heterogeneity in P-body composition, which might reflect functional specializations. CONCLUSIONS This is the first comprehensive in vivo P-body analysis that links a pathogenic condition to P-body alterations. Because of their role in gene expression, the alteration of P-bodies should be further studied to understand fully complex HCV-associated pathologies.
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Affiliation(s)
| | | | - Laura Mensa
- Liver Unit, Hospital Clínic, IDIBAPS, CIBERehd, Barcelona, Spain
| | - Rosa Miquel
- Pathology Department, Hospital Clínic, Barcelona, Spain
| | - Xavier Sanjuan
- Scientific and Technical Services, Universitat Pompeu Fabra, Barcelona, Spain; Advanced Light Microscopy Unit, Center for Genomic Regulation, Barcelona, Spain
| | - Xavier Forns
- Liver Unit, Hospital Clínic, IDIBAPS, CIBERehd, Barcelona, Spain
| | | | - Juana Díez
- Molecular Virology, Universitat Pompeu Fabra, Barcelona, Spain.
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Going full circle: validation of P-body dispersion in hepatitis C virus-infected patients. J Hepatol 2015; 62:756-8. [PMID: 25559325 DOI: 10.1016/j.jhep.2014.12.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 12/20/2014] [Indexed: 12/04/2022]
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Grassi A, Ballardini G. Post-liver transplant hepatitis C virus recurrence: an unresolved thorny problem. World J Gastroenterol 2014; 20:11095-115. [PMID: 25170198 PMCID: PMC4145752 DOI: 10.3748/wjg.v20.i32.11095] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 02/15/2014] [Accepted: 05/29/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV)-related cirrhosis represents the leading cause of liver transplantation in developed, Western and Eastern countries. Unfortunately, liver transplantation does not cure recipient HCV infection: reinfection universally occurs and disease progression is faster after liver transplant. In this review we focus on what happens throughout the peri-transplant phase and in the first 6-12 mo after transplantation: during this crucial period a completely new balance between HCV, liver graft, the recipient's immune response and anti-rejection therapy is achieved that will deeply affect subsequent outcomes. Nearly all patients show an early graft reinfection, with HCV viremia reaching and exceeding pre-transplant levels; in this setting, histological assessment is essential to differentiate recurrent hepatitis C from acute or chronic rejection; however, differentiating the two patterns remains difficult. The host immune response (mainly cellular mediated) appears to be crucial both in the control of HCV infection and in the genesis of rejection, and it is also strongly influenced by immunosuppressive treatment. At present no clear immunosuppressive strategy could be strongly recommended in HCV-positive recipients to prevent HCV recurrence, even immunotherapy appears to be ineffective. Nonetheless it seems reasonable that episodes of rejection and over-immunosuppression are more likely to enhance the risk of HCV recurrence through immunological mechanisms. Both complete prevention of rejection and optimization of immunosuppression should represent the main goals towards reducing the rate of graft HCV reinfection. In conclusion, post-transplant HCV recurrence remains an unresolved, thorny problem because many factors remain obscure and need to be better determined.
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