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Domingo E, García-Crespo C, Perales C. Historical Perspective on the Discovery of the Quasispecies Concept. Annu Rev Virol 2021; 8:51-72. [PMID: 34586874 DOI: 10.1146/annurev-virology-091919-105900] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Viral quasispecies are dynamic distributions of nonidentical but closely related mutant and recombinant viral genomes subjected to a continuous process of genetic variation, competition, and selection that may act as a unit of selection. The quasispecies concept owes its theoretical origins to a model for the origin of life as a collection of mutant RNA replicators. Independently, experimental evidence for the quasispecies concept was obtained from sampling of bacteriophage clones, which revealed that the viral populations consisted of many mutant genomes whose frequency varied with time of replication. Similar findings were made in animal and plant RNA viruses. Quasispecies became a theoretical framework to understand viral population dynamics and adaptability. The evidence came at a time when mutations were considered rare events in genetics, a perception that was to change dramatically in subsequent decades. Indeed, viral quasispecies was the conceptual forefront of a remarkable degree of biological diversity, now evident for cell populations and organisms, not only for viruses. Quasispecies dynamics unveiled complexities in the behavior of viral populations,with consequences for disease mechanisms and control strategies. This review addresses the origin of the quasispecies concept, its major implications on both viral evolution and antiviral strategies, and current and future prospects.
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Affiliation(s)
- Esteban Domingo
- Department of Interactions with the Environment, Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain; .,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Carlos García-Crespo
- Department of Interactions with the Environment, Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
| | - Celia Perales
- Department of Interactions with the Environment, Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain; .,Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, 28029 Madrid, Spain.,Department of Clinical Microbiology, Instituto de Investigación Sanitaria-Fundación Jiménez Díaz University Hospital, Universidad Autónoma de Madrid (IIS-FJD, UAM), 28040 Madrid, Spain
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Suhail M, Sohrab SS, Qureshi A, Tarique M, Abdel-Hafiz H, Al-Ghamdi K, Qadri I. Association of HCV mutated proteins and host SNPs in the development of hepatocellular carcinoma. INFECTION GENETICS AND EVOLUTION 2018; 60:160-172. [PMID: 29501636 DOI: 10.1016/j.meegid.2018.02.034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 02/14/2018] [Accepted: 02/28/2018] [Indexed: 12/13/2022]
Abstract
Hepatitis C virus plays a significant role in the development of hepatocellular carcinoma (HCC) globally. The pathogenic mechanisms of hepatocellular carcinoma with HCV infection are generally linked with inflammation, cytokines, fibrosis, cellular signaling pathways, and liver cell proliferation modulating pathways. HCV encoded proteins (Core, NS3, NS4, NS5A) interact with a broad range of hepatocytes derived factors to modulate an array of activities such as cell signaling, DNA repair, transcription and translational regulation, cell propagation, apoptosis, membrane topology. These four viral proteins are also implicated to show a strong conversion potential in tissue culture. Furthermore, Core and NS5A also trigger the accretion of the β-catenin pathway as a common target to contribute viral induced transformation. There is a strong association between HCV variants within Core, NS4, and NS5A and host single nucleotide polymorphisms (SNPs) with the HCC pathogenesis. Identification of such viral mutants and host SNPs is very critical to determine the risk of HCC and response to antiviral therapy. In this review, we highlight the association of key variants, mutated proteins, and host SNPs in development of HCV induced HCC. How such viral mutants may modulate the interaction with cellular host machinery is also discussed.
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Affiliation(s)
- Mohd Suhail
- King Fahd Medical Research Center, King Abdulaziz University, PO Box 80216, Jeddah 21589, Saudi Arabia
| | - Sayed Sartaj Sohrab
- Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, PO Box 80216, Jeddah 21589, Saudi Arabia
| | - Abid Qureshi
- Biomedical Informatics Centre, Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Srinagar, J&K, India
| | - Mohd Tarique
- Department of Surgery, Sylvester Cancer Center, Miller School of Medicine, University of Miami, Miami, FL 33136, United States
| | - Hany Abdel-Hafiz
- Dept of Medicine, University of Colorado Denver, Aurora, CO 80045, United States
| | - Khalid Al-Ghamdi
- Department of Biological Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ishtiaq Qadri
- Department of Biological Science, King Abdulaziz University, Jeddah, Saudi Arabia.
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Preciado MV, Valva P, Escobar-Gutierrez A, Rahal P, Ruiz-Tovar K, Yamasaki L, Vazquez-Chacon C, Martinez-Guarneros A, Carpio-Pedroza JC, Fonseca-Coronado S, Cruz-Rivera M. Hepatitis C virus molecular evolution: Transmission, disease progression and antiviral therapy. World J Gastroenterol 2014; 20:15992-16013. [PMID: 25473152 PMCID: PMC4239486 DOI: 10.3748/wjg.v20.i43.15992] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 06/22/2014] [Accepted: 08/28/2014] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) infection represents an important public health problem worldwide. Reduction of HCV morbidity and mortality is a current challenge owned to several viral and host factors. Virus molecular evolution plays an important role in HCV transmission, disease progression and therapy outcome. The high degree of genetic heterogeneity characteristic of HCV is a key element for the rapid adaptation of the intrahost viral population to different selection pressures (e.g., host immune responses and antiviral therapy). HCV molecular evolution is shaped by different mechanisms including a high mutation rate, genetic bottlenecks, genetic drift, recombination, temporal variations and compartmentalization. These evolutionary processes constantly rearrange the composition of the HCV intrahost population in a staging manner. Remarkable advances in the understanding of the molecular mechanism controlling HCV replication have facilitated the development of a plethora of direct-acting antiviral agents against HCV. As a result, superior sustained viral responses have been attained. The rapidly evolving field of anti-HCV therapy is expected to broad its landscape even further with newer, more potent antivirals, bringing us one step closer to the interferon-free era.
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Kalvatchev Z, Draganov P. Single-Strand Conformation Polymorphism (SSCP) Analysis: A Rapid and Sensitive Method for Detection of Genetic Diversity Among Virus Population. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.1080/13102818.2005.10817220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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Cerutti A, Maillard P, Minisini R, Vidalain PO, Roohvand F, Pecheur EI, Pirisi M, Budkowska A. Identification of a functional, CRM-1-dependent nuclear export signal in hepatitis C virus core protein. PLoS One 2011; 6:e25854. [PMID: 22039426 PMCID: PMC3200325 DOI: 10.1371/journal.pone.0025854] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 09/12/2011] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) infection is a major cause of chronic liver disease worldwide. HCV core protein is involved in nucleocapsid formation, but it also interacts with multiple cytoplasmic and nuclear molecules and plays a crucial role in the development of liver disease and hepatocarcinogenesis. The core protein is found mostly in the cytoplasm during HCV infection, but also in the nucleus in patients with hepatocarcinoma and in core-transgenic mice. HCV core contains nuclear localization signals (NLS), but no nuclear export signal (NES) has yet been identified.We show here that the aa(109-133) region directs the translocation of core from the nucleus to the cytoplasm by the CRM-1-mediated nuclear export pathway. Mutagenesis of the three hydrophobic residues (L119, I123 and L126) in the identified NES or in the sequence encoding the mature core aa(1-173) significantly enhanced the nuclear localisation of the corresponding proteins in transfected Huh7 cells. Both the NES and the adjacent hydrophobic sequence in domain II of core were required to maintain the core protein or its fragments in the cytoplasmic compartment. Electron microscopy studies of the JFH1 replication model demonstrated that core was translocated into the nucleus a few minutes after the virus entered the cell. The blockade of nucleocytoplasmic export by leptomycin B treatment early in infection led to the detection of core protein in the nucleus by confocal microscopy and coincided with a decrease in virus replication.Our data suggest that the functional NLS and NES direct HCV core protein shuttling between the cytoplasmic and nuclear compartments, with at least some core protein transported to the nucleus. These new properties of HCV core may be essential for virus multiplication and interaction with nuclear molecules, influence cell signaling and the pathogenesis of HCV infection.
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Affiliation(s)
- Andrea Cerutti
- Unité Hépacivirus et Immunité Innée, Département de Virologie, Institut Pasteur, Paris, France
- CNRS, URA3015, Paris, France
- Dipartimento di Medicina Clinica e Sperimentale, Università del Piemonte Orientale “Amedeo Avogadro”, Novara, Italy
| | - Patrick Maillard
- Unité Hépacivirus et Immunité Innée, Département de Virologie, Institut Pasteur, Paris, France
- CNRS, URA3015, Paris, France
| | - Rosalba Minisini
- Dipartimento di Medicina Clinica e Sperimentale, Università del Piemonte Orientale “Amedeo Avogadro”, Novara, Italy
| | - Pierre-Olivier Vidalain
- CNRS, URA3015, Paris, France
- Unité de Génomique Virale et Vaccination, Département de Virologie, Institut Pasteur, Paris, France
| | - Farzin Roohvand
- Unité Hépacivirus et Immunité Innée, Département de Virologie, Institut Pasteur, Paris, France
- CNRS, URA3015, Paris, France
- Hepatitis and AIDS Department, Pasteur Institute of Iran, Teheran, Iran
| | - Eve-Isabelle Pecheur
- Université Lyon 1, Lyon, France
- CNRS, UMR5086, Lyon, France
- IBCP, Bases Moléculaires et Structurales des Systèmes Infectieux, Lyon, France
| | - Mario Pirisi
- Dipartimento di Medicina Clinica e Sperimentale, Università del Piemonte Orientale “Amedeo Avogadro”, Novara, Italy
| | - Agata Budkowska
- Unité Hépacivirus et Immunité Innée, Département de Virologie, Institut Pasteur, Paris, France
- CNRS, URA3015, Paris, France
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Zhang X, Ryu SH, Xu Y, Elbaz T, Zekri ARN, Abdelaziz AO, Abdel-Hamid M, Thiers V, Elena SF, Fan X, Di Bisceglie AM. The Core/E1 domain of hepatitis C virus genotype 4a in Egypt does not contain viral mutations or strains specific for hepatocellular carcinoma. J Clin Virol 2011; 52:333-8. [PMID: 21925935 DOI: 10.1016/j.jcv.2011.08.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Revised: 07/16/2011] [Accepted: 08/22/2011] [Indexed: 12/17/2022]
Abstract
BACKGROUND Hepatitis C virus (HCV) infection is a well-documented etiological factor for hepatocellular carcinoma (HCC). As HCV shows remarkable genetic diversity, an interesting and important issue is whether such a high viral genetic diversity plays a role in the incidence of HCC. Prior data on this subject are conflicting. OBJECTIVES Potential association between HCV genetic mutations or strain variability and HCC incidence has been examined through a comparative genetic analysis merely focused on a single HCV subtype (genotype 4a) in a single country (Egypt). STUDY DESIGN The study focused on three HCV sequence datasets with explicit sampling dates and disease patterns. An overlapping HCV Core/E1 domain from three datasets was used as the target for comparative analysis through genetic and phylogenetic approaches. RESULTS Based on partial Core/E1 domain (387 bp), genetic and phylogenetic analysis did not identify any HCC-specific viral mutations and strains, respectively. CONCLUSIONS The Core/E1 domain of HCV genotype 4a in Egypt does not contain HCC-specific mutations or strains. Additionally, sequence errors resulting from the polymerase chain reaction, together with a strong evolutionary pressure on HCV in patients with end-stage liver disease, have significant potential to bias data generation and interpretation.
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Affiliation(s)
- Xiaoan Zhang
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
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Sequence variability of HCV Core region: Important predictors of HCV induced pathogenesis and viral production. INFECTION GENETICS AND EVOLUTION 2011; 11:543-56. [DOI: 10.1016/j.meegid.2011.01.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Revised: 01/17/2011] [Accepted: 01/21/2011] [Indexed: 02/07/2023]
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Fishman SL, Factor SH, Balestrieri C, Fan X, Dibisceglie AM, Desai SM, Benson G, Branch AD. Mutations in the hepatitis C virus core gene are associated with advanced liver disease and hepatocellular carcinoma. Clin Cancer Res 2009; 15:3205-13. [PMID: 19383824 DOI: 10.1158/1078-0432.ccr-08-2418] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE Hepatitis C virus (HCV) infection can promote the development of hepatocellular carcinoma (HCC). Published data implicate the HCV core gene in oncogenesis. We tested the hypothesis that core gene sequences from HCC patients differ from those of patients without cirrhosis/HCC. EXPERIMENTAL DESIGN Full-length HCV sequences from HCC patients and controls were obtained from the investigators and GenBank and compared with each other. A logistic regression model was developed to predict the HCC risk of individual point mutations and other sequence features. Mutations in partial sequences (bases 36-288) from HCC patients and controls were also analyzed. The first base of the AUG start codon was designated position 1. RESULTS A logistic regression model developed through analysis of full-length core gene sequences identified seven polymorphisms significantly associated with increased HCC risk (36G/C, 209A, 271U/C, 309A/C, 435A/C, 481A, and 546A/C) and an interaction term (for 209A-271U/C) that had an odds ratio <1.0. Three of these polymorphisms could be analyzed in the partial sequences. Two of them, 36G/C and 209A, were again associated with increased HCC risk, but 271U/C was not. The odds ratio of 209A-271U/C was not significant. CONCLUSIONS HCV core genes from patients with and without HCC differ at several positions. Of interest, 209A has been associated with IFN resistance and HCC in previous studies. Our findings suggest that HCV core gene sequence data might provide useful information about HCC risk. Prospective investigation is needed to establish the temporal relationship between appearance of the viral mutations and development of HCC.
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Affiliation(s)
- Sarah L Fishman
- Department of Medicine, Mount Sinai School of Medicine, New York, NY, USA
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Abstract
Hepatocellular carcinoma (HCC) is a frequent malignancy worldwide with a high rate of metastasis. The hepatitis B and C viruses are considered major etiological factors associated with the development of HCC, particularly as a result of their induction of chronic inflammation. There is increasing evidence that the inflammatory process is inherently associated with many different cancer types, including HCC. Specifically, this review aims to cover evidence for the potential roles of cytokines, an important component of the immune system, in promoting HCC carcinogenesis and progression. A global summary of cytokine levels, functions, polymorphisms, and therapies with regard to HCC is presented. In particular, the role of proinflammatory Th1 and anti-inflammatory Th2 cytokine imbalances in the microenvironment of HCC patients with metastasis and the possible clinical significance of these findings are addressed. Overall, multiple studies, spanning many decades, have begun to elucidate the important role of cytokines in HCC.
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Affiliation(s)
- Anuradha Budhu
- National Cancer Institute, 37 Convent Dr., Bldg. 37, Rm. 3044A, Bethesda, MD 20892, USA
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Giannini C, Bréchot C. Hepatitis C virus biology. Cell Death Differ 2003; 10 Suppl 1:S27-38. [PMID: 12655344 DOI: 10.1038/sj.cdd.4401121] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2002] [Revised: 06/11/2002] [Accepted: 06/13/2002] [Indexed: 02/07/2023] Open
Abstract
Hepatitis C virus infection represents a major problem of public health with around 350 millions of chronically infected individuals worldwide. The frequent evolution towards severe liver disease and cancer are the main features of HCV chronic infection. Antiviral therapies, mainly based on the combination of IFN and ribavirin can only assure a long term eradication of the virus in less than half of treated patients. The mechanisms underlying HCV pathogenesis and persistence in the host are still largely unknown and the efforts made by researchers in the understanding the viral biology have been hampered by the absence of a reliable in vitro and in vivo system reproducing HCV infection. The present review will mainly focus on viral pathogenetic mechanisms based on the interaction of HCV proteins (especially core, NS3 and NS5A) with host cellular signaling transduction pathways regulating cell growth and viability and on the strategies developed by the virus to persist in the host and escape to antiviral therapy. Past and recent data obtained in this field with different experimental approaches will be discussed.
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Affiliation(s)
- C Giannini
- Liver Cancer and Molecular Virology, Pasteur-INSERM Unit 370, 156, Rue de Vaugirard 75015 Paris, France
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Ogata S, Nagano-Fujii M, Ku Y, Yoon S, Hotta H. Comparative sequence analysis of the core protein and its frameshift product, the F protein, of hepatitis C virus subtype 1b strains obtained from patients with and without hepatocellular carcinoma. J Clin Microbiol 2002; 40:3625-30. [PMID: 12354856 PMCID: PMC130847 DOI: 10.1128/jcm.40.10.3625-3630.2002] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The core protein of hepatitis C virus (HCV) has been implicated in hepatocarcinogenesis. In order to determine whether there is a correlation between mutations of the core protein and the development of hepatocellular carcinoma (HCC), the core protein-coding sequence of the viral genome of HCV subtype 1b (HCV-1b) obtained from patients with and without HCC was analyzed. We found that 12 (40.0%) of 30 HCV-1b isolates from patients with HCC but none of 29 isolates from patients without HCC had a point mutation(s) in an N-terminal region of 20 residues. Similarly, 10 (33.3%) of 30 isolates from patients with HCC had mutations in a limited region between residues 141 and 160, whereas only 2 (6.9%) of 29 isolates from patients without HCC did. The differences between the two groups were statistically significant. The mutations were found in isolates from both cancerous and adjacent noncancerous tissues of patients with HCC, suggesting that the mutations were present before the development of HCC. The other regions of the core protein of some isolates also had mutations, but no significant difference was observed between isolates from patients with HCC and those from patients without HCC. The F protein, a frameshift product that is still hypothetical for HCV-1b strains, showed more sequence diversity than the core protein among the isolates analyzed, but there were no significant differences in the mutation rates or positions between isolates from patients with HCC and isolates from patients without HCC, except for a short N-terminal sequence of approximately 11 residues that is shared with the core protein.
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Affiliation(s)
- Satoshi Ogata
- Department of Microbiology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan
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Rullier A, Trimoulet P, Urbaniak R, Winnock M, Zauli D, Ballardini G, Rosenbaum J, Balabaud C, Bioulac-Sage P, Le Bail B. Immunohistochemical detection of hcv in cirrhosis, dysplastic nodules, and hepatocellular carcinomas with parallel-tissue quantitative RT-PCR. Mod Pathol 2001; 14:496-505. [PMID: 11353061 DOI: 10.1038/modpathol.3880338] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Hepatitis C virus is a major risk factor for hepatocarcinogenesis in humans. In situ detection of the virus in early sequential lesions of hepatocarcinogenesis could provide information about the role of the virus in the transformation and promotion process. Parallel in situ detection of HCV proteins and RNA in human tissues were performed in 55 posthepatitis C cirrhosis, 17 dysplastic nodules (DN), and 25 hepatocellular carcinomas (HCC), using immunohistochemistry and tissue quantitative RT-PCR. A consistent cytoplasmic hepatocellular staining was obtained in 73% of cirrhosis cases (with or without HCC) and in 55% DN cases. A few tumoral hepatocytes were unambiguously stained in 28% HCC. The percentage of positive cells and the intensity of immunostaining significantly decreased from cirrhosis to HCC through DN, whereas there was no difference in the prevalence of positivity or the number of viral copies between cirrhosis and HCC using tissue-quantitative RT-PCR. Finally, RT-PCR levels were found parallel with the immunostaining in cirrhosis but not in HCC. These results suggest that HCV protein synthesis may persist but be down-regulated during sequential hepatocarcinogenesis. A putative role of HCV proteins on cell proliferation and differentiation during the early steps of carcinogenesis cannot therefore be excluded.
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Affiliation(s)
- A Rullier
- Service d'Anatomie Pathologique, Hôpital Pellegrin, Bordeause, France
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Kato N. Genome of human hepatitis C virus (HCV): gene organization, sequence diversity, and variation. MICROBIAL & COMPARATIVE GENOMICS 2001; 5:129-51. [PMID: 11252351 DOI: 10.1089/omi.1.2000.5.129] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Hepatitis C virus (HCV) is the major etiologic agent of non-A, non-B hepatitis. HCV infection frequently causes chronic hepatitis, which progresses to liver cirrhosis and hepatocellular carcinoma. Since the discovery of HCV in 1989, a large number of genetic analyses of HCV have been reported, and the viral genome structure has been elucidated. An enveloped virus, HCV belongs to the family Flaviviridae, whose genome consists of a positive-stranded RNA molecule of about 9.6 kilobases and encodes a large polyprotein precursor (about 3000 amino acids). This precursor protein is cleaved by the host and viral proteinase to generate at least 10 proteins: the core, envelope 1 (E1), E2, p7, nonstructural (NS) 2, NS3, NS4A, NS4B, NS5A, and NS5B. These HCV proteins not only function in viral replication but also affect a variety of cellular functions. HCV has been found to have remarkable genetic heterogeneity. To date, more than 30 HCV genotypes have been identified worldwide. Furthermore, HCV may show quasispecies distribution in an infected individual. These findings may have important implications in diagnosis, pathogenesis, treatment, and vaccine development. The hypervariable region 1 found within the envelope E2 protein was shown to be a major site for the genetic evolution of HCV after the onset of hepatitis, and might be involved in escape from the host immunesurveillance system.
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Affiliation(s)
- N Kato
- Department of Molecular Biology, Institute of Cellular and Molecular Biology, Okayama University Medical School, Japan.
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14
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Kalvatchev Z, Walder R, Garzaro D, Barrios M. Detection of genetic diversity among bovine immunodeficiency virus population by single-strand conformation polymorphism analysis. Viral Immunol 2001; 13:373-81. [PMID: 11016600 DOI: 10.1089/08828240050144680] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Serial virus specimens rescued from rabbits, experimentally infected with bovine immunodeficiency (BIV) strain R29, were monitored for changes in quasispecies population, using the single-strand conformation polymorphism (SSCP) analysis. The generation of characteristic SSCP patterns enables the rapid differentiation of BIV variants derived from the conserved part on the env region of the BIV genome, reducing the need for expensive and time-consuming direct sequencing analyses. Our results showed genetic polymorphism among a number of sampled BIV population in experimentally infected rabbits. At least three SSCP patterns (BIV quasispecies) were detected. The SSCP analysis allows for an easy, sensitive, and rapid screening of genetic variants of the virus and the assessment of variation at a number of tissue target sites. These variations may relate to cell-type targets and/or disease progression, and could be significant to our understanding of lentiviral pathogenesis.
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Affiliation(s)
- Z Kalvatchev
- Laboratorio de Virus Animales, Centro de Microbiología y Biologia Celular, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
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15
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R�ster B, Zeuzem S, Krump-Konvalinkova V, Berg T, Jonas S, Severin K, Roth WK. Comparative sequence analysis of the core- and NS5-region of hepatitis C virus from tumor and adjacent non-tumor tissue. J Med Virol 2001. [DOI: 10.1002/1096-9071(20000201)63:2<128::aid-jmv1007>3.0.co;2-s] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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16
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Takahashi I, Iijima H, Katashima R, Itakura M, Kiyono H. Clonal Expansion of CD4+ TCRββ+ T Cells in TCR α-Chain- Deficient Mice by Gut-Derived Antigens. THE JOURNAL OF IMMUNOLOGY 1999. [DOI: 10.4049/jimmunol.162.3.1843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
A population of CD4+ α−β+ T cells increases in the mucosal and peripheral lymphoid tissues of TCRα-chain-deficient mice with inflammatory bowel disease. The α−β+ T cells, which produce predominantly IL-4, mediate the proliferation of colonic epithelial crypts and the infiltration of large numbers of IgA-producing plasma cells into the lamina propria of the colon. To examine whether enteric Ags were recognized by a population of monoclonal α−β+ T cells leading to the intestinal inflammation, we examined the usage and clonotypes of TCR expressed by the α−β+ T cells in TCRα-chain-deficient mice with inflammatory bowel disease. Analyses of immunoprecipitates by two dimensional electrophoresis and single-cell RT-PCR revealed that TCR of the α−β+ T cells was a homodimer of β-chains that was capable of recognizing luminal bacterial Ags. PCR single-strand conformation polymorphism analysis of TCR Vβ transcripts revealed monoclonal accumulation of the α−β+ T cells in the colonic lamina propria of the diseased mice. DNA sequencing revealed the accumulation of the α−β+ T cells with the same CDR3 sequences in the colon. These findings suggest that the pathogenic CD4+ α−β+ T cells expressing a homodimeric form of the TCRβ-chains can be clonally expanded upon the stimulation with gut-derived Ags.
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Affiliation(s)
- Ichiro Takahashi
- *Department of Mucosal Immunology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan; and
| | - Hideki Iijima
- *Department of Mucosal Immunology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan; and
| | - Rumi Katashima
- †Otsuka Department of Clinical and Molecular Nutrition, School of Medicine, University of Tokushima, Tokushima, Japan
| | - Mitsuo Itakura
- †Otsuka Department of Clinical and Molecular Nutrition, School of Medicine, University of Tokushima, Tokushima, Japan
| | - Hiroshi Kiyono
- *Department of Mucosal Immunology, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan; and
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17
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Farci P, Bukh J, Purcell RH. The quasispecies of hepatitis C virus and the host immune response. SPRINGER SEMINARS IN IMMUNOPATHOLOGY 1997; 19:5-26. [PMID: 9266628 DOI: 10.1007/bf00945022] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- P Farci
- Istituto di Medicina Interna, University of Cagliari, Italy
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