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de Souza Andrade A, Oliveira Campos S, Dias J, Campos MA, Kroon EG. Dengue virus 3 genotype I (GI) lineage 1 (L1) isolates elicit differential cytopathic effect with syncytium formation in human glioblastoma cells (U251). Virol J 2023; 20:204. [PMID: 37661255 PMCID: PMC10476378 DOI: 10.1186/s12985-023-02168-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023] Open
Abstract
BACKGROUND Dengue virus (DENV) is a Flaviviridae member classified into four antigenically distinct serotypes (DENV 1, 2, 3, and 4) and further subdivided genotypes. DENV3 is subdivided into four or five genotypes, depending on the classification adopted. Despite their high genetic proximity, as revealed by phylogenetic complete polyprotein analysis, DENV3 MG-20 and DENV3 PV_BR showed different neurovirulence in mice models. Our group identified six amino acid mutations in protein E, including the E62K and E123Q, which may affect interactions of hydrophobic clusters on domain II, thus leading to the observed differences in the studied viruses. METHODS Human glioblastoma cells (U251) derived from a malignant glioblastoma tumor by explant technique were infected by the DENV3 GIL1 isolates DENV3 MG-20 and DENV3 PV_BR and analyzed by plaque assays and titration, optical, immunofluorescence, and transmission electronic microscopy. RESULTS The two isolates showed different cytopathic effects (CPE) and fusogenic patterns, further confirmed by indirect immunofluorescence. Transmission electron microscopy revealed intense cytopathic effects in DENV3 MG-20 infected U251 cells, displaying endoplasmic reticulum hypertrophy and turgid vesicles with proteins and multiple viruses, distinct from DENV3 PV_BR infected cells. It is hypothesized that the different amino acids in the DENV3 MG-20 isolate are related to an increased membrane fusion ability in viral infection, thus facilitating immune system evasion and increased chances of central nervous system cell infection. CONCLUSION These results emphasize the biological differences between the isolates, which could be a critical factor in host-virus interaction and severe dengue development. Our study presents comparative results of highly similar isolates with the potential to generate more subsidies for a deeper understanding of the DENV pathogenesis. The neurotropism of the isolate DENV3 MG-20 (belonging to the DENV3 GI L1 genotype) showing infection of nervous system cells (U251) could contribute to understanding neurological dengue disease.
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Affiliation(s)
- Adriana de Souza Andrade
- Laboratório de Vírus, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Imunologia de Doenças Virais, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brasil
| | - Sofia Oliveira Campos
- Imunologia de Doenças Virais, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brasil
| | - Jamile Dias
- Laboratório de Vírus, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Marco Antônio Campos
- Imunologia de Doenças Virais, Instituto René Rachou, Fundação Oswaldo Cruz, Belo Horizonte, Minas Gerais, Brasil
| | - Erna Geessien Kroon
- Laboratório de Vírus, Departamento de Microbiologia, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
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Leroy H, Han M, Woottum M, Bracq L, Bouchet J, Xie M, Benichou S. Virus-Mediated Cell-Cell Fusion. Int J Mol Sci 2020; 21:E9644. [PMID: 33348900 PMCID: PMC7767094 DOI: 10.3390/ijms21249644] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/11/2020] [Accepted: 12/14/2020] [Indexed: 02/07/2023] Open
Abstract
Cell-cell fusion between eukaryotic cells is a general process involved in many physiological and pathological conditions, including infections by bacteria, parasites, and viruses. As obligate intracellular pathogens, viruses use intracellular machineries and pathways for efficient replication in their host target cells. Interestingly, certain viruses, and, more especially, enveloped viruses belonging to different viral families and including human pathogens, can mediate cell-cell fusion between infected cells and neighboring non-infected cells. Depending of the cellular environment and tissue organization, this virus-mediated cell-cell fusion leads to the merge of membrane and cytoplasm contents and formation of multinucleated cells, also called syncytia, that can express high amount of viral antigens in tissues and organs of infected hosts. This ability of some viruses to trigger cell-cell fusion between infected cells as virus-donor cells and surrounding non-infected target cells is mainly related to virus-encoded fusion proteins, known as viral fusogens displaying high fusogenic properties, and expressed at the cell surface of the virus-donor cells. Virus-induced cell-cell fusion is then mediated by interactions of these viral fusion proteins with surface molecules or receptors involved in virus entry and expressed on neighboring non-infected cells. Thus, the goal of this review is to give an overview of the different animal virus families, with a more special focus on human pathogens, that can trigger cell-cell fusion.
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Affiliation(s)
- Héloïse Leroy
- Institut Cochin, Inserm U1016, 75014 Paris, France; (H.L.); (M.H.); (M.W.)
- Centre National de la Recherche Scientifique CNRS, UMR8104, 75014 Paris, France
- Faculty of Health, University of Paris, 75014 Paris, France
| | - Mingyu Han
- Institut Cochin, Inserm U1016, 75014 Paris, France; (H.L.); (M.H.); (M.W.)
- Centre National de la Recherche Scientifique CNRS, UMR8104, 75014 Paris, France
- Faculty of Health, University of Paris, 75014 Paris, France
| | - Marie Woottum
- Institut Cochin, Inserm U1016, 75014 Paris, France; (H.L.); (M.H.); (M.W.)
- Centre National de la Recherche Scientifique CNRS, UMR8104, 75014 Paris, France
- Faculty of Health, University of Paris, 75014 Paris, France
| | - Lucie Bracq
- Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland;
| | - Jérôme Bouchet
- Laboratory Orofacial Pathologies, Imaging and Biotherapies UR2496, University of Paris, 92120 Montrouge, France;
| | - Maorong Xie
- Division of Infection and Immunity, University College London, London WC1E 6BT, UK;
| | - Serge Benichou
- Institut Cochin, Inserm U1016, 75014 Paris, France; (H.L.); (M.H.); (M.W.)
- Centre National de la Recherche Scientifique CNRS, UMR8104, 75014 Paris, France
- Faculty of Health, University of Paris, 75014 Paris, France
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Ventura GT, da Costa ECB, Capaccia AM, Mohana-Borges R. pH-dependent conformational changes in the HCV NS3 protein modulate its ATPase and helicase activities. PLoS One 2014; 9:e115941. [PMID: 25551442 PMCID: PMC4281115 DOI: 10.1371/journal.pone.0115941] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 11/29/2014] [Indexed: 11/29/2022] Open
Abstract
The hepatitis C virus (HCV) infects 170 to 200 million people worldwide and is, therefore, a major health problem. The lack of efficient treatments that specifically target the viral proteins or RNA and its high chronicity rate make hepatitis C the cause of many deaths and hepatic transplants annually. The NS3 protein is considered an important target for the development of anti-HCV drugs because it is composed of two domains (a serine protease in the N-terminal portion and an RNA helicase/NTPase in the C-terminal portion), which are essential for viral replication and proliferation. We expressed and purified both the NS3 helicase domain (NS3hel) and the full-length NS3 protein (NS3FL) and characterized pH-dependent structural changes associated with the increase in their ATPase and helicase activities at acidic pH. Using intrinsic fluorescence experiments, we have observed that NS3hel was less stable at pH 6.4 than at pH 7.2. Moreover, binding curves using an extrinsic fluorescent probe (bis-ANS) and ATPase assays performed under different pH conditions demonstrated that the hydrophobic clefts of NS3 are significantly more exposed to the aqueous medium at acidic pH. Using fluorescence spectroscopy and anisotropy assays, we have also observed more protein interaction with DNA upon pH acidification, which suggests that the hydrophobic clefts exposure on NS3 might be related to a loss of stability that could lead it to adopt a more open conformation. This conformational change at acidic pH would stimulate both its ATPase and helicase activities, as well as its ability to bind DNA. Taken together, our results indicate that the NS3 protein adopts a more open conformation due to acidification from pH 7.2 to 6.4, resulting in a more active form at a pH that is found near Golgi-derived membranes. This increased activity could better allow NS3 to carry out its functions during HCV replication.
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Affiliation(s)
- Gustavo Tavares Ventura
- Laboratório de Genômica Estrutural, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Emmerson Corrêa Brasil da Costa
- Laboratório de Genômica Estrutural, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Anne Miranda Capaccia
- Laboratório de Genômica Estrutural, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Ronaldo Mohana-Borges
- Laboratório de Genômica Estrutural, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- * E-mail:
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Human cell types important for hepatitis C virus replication in vivo and in vitro: old assertions and current evidence. Virol J 2011; 8:346. [PMID: 21745397 PMCID: PMC3142522 DOI: 10.1186/1743-422x-8-346] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 07/11/2011] [Indexed: 12/12/2022] Open
Abstract
Hepatitis C Virus (HCV) is a single stranded RNA virus which produces negative strand RNA as a replicative intermediate. We analyzed 75 RT-PCR studies that tested for negative strand HCV RNA in liver and other human tissues. 85% of the studies that investigated extrahepatic replication of HCV found one or more samples positive for replicative RNA. Studies using in situ hybridization, immunofluorescence, immunohistochemistry, and quasispecies analysis also demonstrated the presence of replicating HCV in various extrahepatic human tissues, and provide evidence that HCV replicates in macrophages, B cells, T cells, and other extrahepatic tissues. We also analyzed both short term and long term in vitro systems used to culture HCV. These systems vary in their purposes and methods, but long term culturing of HCV in B cells, T cells, and other cell types has been used to analyze replication. It is therefore now possible to study HIV-HCV co-infections and HCV replication in vitro.
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Role for ADP ribosylation factor 1 in the regulation of hepatitis C virus replication. J Virol 2010; 85:946-56. [PMID: 21068255 DOI: 10.1128/jvi.00753-10] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
We hypothesized that ADP-ribosylation factor 1 (Arf1) plays an important role in the biogenesis and maintenance of infectious hepatitis C virus (HCV). Huh7.5 cells, in which HCV replicates and produces infectious viral particles, were exposed to brefeldin A or golgicide A, pharmacological inhibitors of Arf1 activation. Treatment with these agents caused a reduction in viral RNA levels, the accumulation of infectious particles within the cells, and a reduction in the levels of these particles in the extracellular medium. Fluorescence analyses showed that the viral nonstructural (NS) proteins NS5A and NS3, but not the viral structural protein core, shifted their localization from speckle-like structures in untreated cells to the rims of lipid droplets (LDs) in treated cells. Using pulldown assays, we showed that ectopic overexpression of NS5A in Huh7 cells reduces the levels of GTP-Arf1. Downregulation of Arf1 expression by small interfering RNA (siRNA) decreased both the levels of HCV RNA and the production of infectious viral particles and altered the localization of NS5A to the peripheries of LDs. Together, our data provide novel insights into the role of Arf1 in the regulation of viral RNA replication and the production of infectious HCV.
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Subcellular forms and biochemical events triggered in human cells by HCV polyprotein expression from a viral vector. Virol J 2008; 5:102. [PMID: 18793431 PMCID: PMC2553408 DOI: 10.1186/1743-422x-5-102] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 09/15/2008] [Indexed: 12/16/2022] Open
Abstract
To identify the subcellular forms and biochemical events induced in human cells after HCV polyprotein expression, we have used a robust cell culture system based on vaccinia virus (VACV) that efficiently expresses in infected cells the structural and nonstructural proteins of HCV from genotype 1b (VT7-HCV7.9). As determined by confocal microscopy, HCV proteins expressed from VT7-HCV7.9 localize largely in a globular-like distribution pattern in the cytoplasm, with some proteins co-localizing with the endoplasmic reticulum (ER) and mitochondria. As examined by electron microscopy, HCV proteins induced formation of large electron-dense cytoplasmic structures derived from the ER and containing HCV proteins. In the course of HCV protein production, there is disruption of the Golgi apparatus, loss of spatial organization of the ER, appearance of some "virus-like" structures and swelling of mitochondria. Biochemical analysis demonstrate that HCV proteins bring about the activation of initiator and effector caspases followed by severe apoptosis and mitochondria dysfunction, hallmarks of HCV cell injury. Microarray analysis revealed that HCV polyprotein expression modulated transcription of genes associated with lipid metabolism, oxidative stress, apoptosis, and cellular proliferation. Our findings demonstrate the uniqueness of the VT7-HCV7.9 system to characterize morphological and biochemical events related to HCV pathogenesis.
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Critical role of virion-associated cholesterol and sphingolipid in hepatitis C virus infection. J Virol 2008; 82:5715-24. [PMID: 18367533 DOI: 10.1128/jvi.02530-07] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In this study, we establish that cholesterol and sphingolipid associated with hepatitis C virus (HCV) particles are important for virion maturation and infectivity. In a recently developed culture system enabling study of the complete life cycle of HCV, mature virions were enriched with cholesterol as assessed by the molar ratio of cholesterol to phospholipid in virion and cell membranes. Depletion of cholesterol from the virus or hydrolysis of virion-associated sphingomyelin almost completely abolished HCV infectivity. Supplementation of cholesterol-depleted virus with exogenous cholesterol enhanced infectivity to a level equivalent to that of the untreated control. Cholesterol-depleted or sphingomyelin-hydrolyzed virus had markedly defective internalization, but no influence on cell attachment was observed. Significant portions of HCV structural proteins partitioned into cellular detergent-resistant, lipid-raft-like membranes. Combined with the observation that inhibitors of the sphingolipid biosynthetic pathway block virion production, but not RNA accumulation, in a JFH-1 isolate, our findings suggest that alteration of the lipid composition of HCV particles might be a useful approach in the design of anti-HCV therapy.
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Valli MB, Crema A, Lanzilli G, Serafino A, Bertolini L, Ravagnan G, Ponzetto A, Menzo S, Clementi M, Carloni G. Molecular and cellular determinants of cell-to-cell transmission of HCV in vitro. J Med Virol 2007; 79:1491-9. [PMID: 17705190 DOI: 10.1002/jmv.20947] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
It was reported previously that HCV can be transmitted from persistently infected human bone-marrow-derived B-lymphoblastoid cells (TO.FE(HCV)) to human hepatoma cells by cell-to-cell contact. The present study confirms and characterize further such type of HCV infection in vitro. TO.FE(HCV) cells were co-cultured with 2.2.15 hepatoma cells, that are not susceptible to cell-free infection by sera containing HCV of 1b genotype. By this co-cultivation system it was demonstrated that HCV transmission to recipient cells requires de novo virus RNA replication. Several factors may favor HCV-transmission, evidence is provided that TO.FE(HCV) cells were able to select HCV-quasispecies. 5'-UTR and core sequence analysis revealed differences in the HCV-quasispecies composition in serum inoculum and in infected TO.FE B-cells at 4 months post-inoculation. It is considered that the latter may be more successful in replicating HCV in vitro and used to express surface molecules which may be involved in cell-to-cell contact. In TO.FE(HCV) cells replicate distinct, or few close related, HCV-variants correlated with those of serum inoculum. Comparative analysis of tetra-spans and integrins expression undertaken by cytofluorimetry displayed higher level of expression for TO.FE cells in comparison to other human bone-marrow-derived B-cell lines. Overall, the observed persistent in vitro HCV replication is mediated by a continuous cell-to-cell reinfection that may be favored by selection of viral variants and expression of molecules involved in cell adhesion. These observations may provide an explanation for the establishment of HCV infection, the occurrence of chronic infection and HCV-related lymphoproliferative diseases.
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Affiliation(s)
- Maria Beatrice Valli
- Institute of Neurobiology and Molecular Medicine, National Research Council (CNR), Roma, Italy
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9
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Suzuki T, Ishii K, Aizaki H, Wakita T. Hepatitis C viral life cycle. Adv Drug Deliv Rev 2007; 59:1200-12. [PMID: 17825945 DOI: 10.1016/j.addr.2007.04.014] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Accepted: 04/11/2007] [Indexed: 12/16/2022]
Abstract
Hepatitis C virus (HCV) has been recognized as a major cause of chronic liver diseases worldwide. Molecular studies of the virus became possible with the successful cloning of its genome in 1989. Although much work remains to be done regarding early and late stages of the HCV life cycle, significant progress has been made with respect to the molecular biology of HCV, especially the viral protein processing and the genome replication. This review summarizes our current understanding of genomic organization of HCV, features of the viral protein characteristics, and the viral life cycle.
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Affiliation(s)
- Tetsuro Suzuki
- Department of Virology II, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
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Pawlotsky JM, Chevaliez S, McHutchison JG. The hepatitis C virus life cycle as a target for new antiviral therapies. Gastroenterology 2007; 132:1979-98. [PMID: 17484890 DOI: 10.1053/j.gastro.2007.03.116] [Citation(s) in RCA: 247] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2007] [Accepted: 03/23/2007] [Indexed: 12/11/2022]
Abstract
The burden of disease consequent to hepatitis C virus (HCV) infection has been well described and is expected to increase dramatically over the next decade. Current approved antiviral therapies are effective in eradicating the virus in approximately 50% of infected patients. However, pegylated interferon and ribavirin-based therapy is costly, prolonged, associated with significant adverse effects, and not deemed suitable for many HCV-infected patients. As such, there is a clear and pressing need for the development of additional agents that act through alternate or different mechanisms, in the hope that such regimens could lead to enhanced response rates more broadly applicable to patients with hepatitis C infection. Recent basic science enhancements in HCV cell culture systems and replication assays have led to a broadening of our understanding of many of the mechanisms of HCV replication and, therefore, potential novel antiviral targets. In this article, we have attempted to highlight important new information as it relates to our understanding of the HCV life cycle. These steps broadly encompass viral attachment, entry, and fusion; viral RNA translation; posttranslational processing; HCV replication; and viral assembly and release. In each of these areas, we present up-to-date knowledge of the relevant aspects of that component of the viral life cycle and then describe the preclinical and clinical development targets and pathways being explored in the translational and clinical settings.
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Affiliation(s)
- Jean-Michel Pawlotsky
- French National Reference Center for Viral Hepatitis B, C, and delta, Department of Virology, Hôpital Henri Mondor, Université Paris 12, Créteil, France.
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Yi Z, Fang C, Pan T, Wang J, Yang P, Yuan Z. Subproteomic study of hepatitis C virus replicon reveals Ras-GTPase-activating protein binding protein 1 as potential HCV RC component. Biochem Biophys Res Commun 2006; 350:174-8. [PMID: 16996479 DOI: 10.1016/j.bbrc.2006.09.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2006] [Accepted: 09/07/2006] [Indexed: 01/22/2023]
Abstract
Hepatitis C virus (HCV) RNA synthesis takes place on a detergent resistant membrane (DRM) structure. To identify potential cellular proteins related to HCV replication complexes (RC), we purified DRMs from HCV subgenomic replicon cells and its parental Huh7 cells. The proteins of DRM fractions were separated by two-dimensional gel electrophoresis and identified by mass spectrometry. Comparing with parental Huh7 cells, 60 proteins were up-regulated while 14 proteins were down-regulated in HCV replicon cells. Ras-GTPase-activating protein binding protein 1 (G3BP1), one of the elevated proteins, was found to be associated with HCV NS5B and knockdown of G3BP1 by siRNA in HCV replicon cells significantly reduced HCV replication, which may indicate it a potential component of HCV RC. These results suggest that HCV viral gene and proteins may regulate the presence of host cellular proteins in DRM, ensure appropriate concentrations of replication components, and hence control the rates or efficiencies of HCV replication.
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Affiliation(s)
- Zhigang Yi
- Key Laboratory of Medical Molecular Virology, Institute of Medical Microbiology, Shanghai Medical College, Fudan University, Shanghai 200032, China
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12
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Paraná R, Schinoni MI, de Freitas LAR, Codes L, Cruz M, Andrade Z, Trepo C. Anti-Golgi complex antibodies during pegylated-interferon therapy for hepatitis C. Liver Int 2006; 26:1148-54. [PMID: 17032416 DOI: 10.1111/j.1478-3231.2006.01345.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
BACKGROUND/AIM Pegylated interferon (Peg-IFN) plus ribavirin is the standard therapy for hepatitis C. Peg-IFN has several antiviral mechanisms, but its role in hepatitis C treatment seems to be related to its immunomodulatory effect. Ribavirin, an antiviral agent, potentiates IFN activity when added to it. Both drugs are associated with adverse reactions of different magnitudes. Autoimmune phenomena have been reported with this treatment. In this paper, we describe cases of ALT/GGT flares during Peg-IFN plus ribavirin treatment, which related to the appearance of anti-Golgi antibody and disease progress. METHODS We investigated three patients with hepatitis C and severe ALT/GGT flares during Peg-IFN and ribavirin treatment coinciding with anti-Golgi complex antibody as the only marker of autoimmunity. We then reviewed the medical files and tested anti-Golgi antibody in stored sera from 25 patients treated with conventional IFN and in 14 patients treated with Peg-IFN. RESULTS The three patients were male, over 45 years of age; all were relapsers and non-responders. Anti-Golgi antibody was positive during treatment coinciding with ALT/GGT flares but with hepatitis C virus (HCV)-RNA negativity, disappearing after stopping treatment, with normalization of ALT/AST levels. One patient had progression of fibrosis from F2 to F3 despite negativity of HCV-RNA. In the last group, only two patients treated with Peg-IFN experienced ALT/GGT flares but without anti-Golgi antibody CONCLUSIONS The presence of anti-Golgi complex antibody could be a marker of a temporary autoimmune phenomenon and progressive disease.
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Affiliation(s)
- Raymundo Paraná
- Gastro-Hepatology Unit, Faculty of Medicine, University Hospital of Bahia, Bahia, Brazil.
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Choi J, Forman HJ, Ou JH, Lai MMC, Seronello S, Nandipati A. Redox modulation of the hepatitis C virus replication complex is calcium dependent. Free Radic Biol Med 2006; 41:1488-98. [PMID: 17023276 DOI: 10.1016/j.freeradbiomed.2006.08.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Revised: 06/24/2006] [Accepted: 08/09/2006] [Indexed: 02/06/2023]
Abstract
Reactive species and perturbation of the redox balance have been implicated in the pathogenesis of many viral diseases, including hepatitis C. Previously, we made a surprising discovery that concentrations of H(2)O(2) that are nontoxic to host cells disrupted the hepatitis C virus (HCV) replication complex (RC) in Huh7 human hepatoma cells in a manner that suggested signaling. Here, we show that H(2)O(2) and interferon-gamma have comparable effects on the HCV subgenomic and genomic RNA replication in Huh7 cells. H(2)O(2) induced a gradual rise in the intracellular calcium concentration ([Ca(2+)](i)). Both rapid and sustained suppression of HCV RNA replication by H(2)O(2) depended on this calcium elevation. The peroxide-induced [Ca(2+)](i) elevation was independent of extracellular calcium and derived, at least in part, from the endoplasmic reticulum. Likewise, the suppression of the HCV RC by H(2)O(2) was independent of extracellular calcium but required an intracellular calcium source. Other agents that elevated [Ca(2+)](i) could also suppress the HCV RC, suggesting that calcium elevation might be sufficient to suppress HCV RNA replication. In conclusion, oxidants may modulate the HCV RC through calcium. Effects on the infectivity and the morphogenesis of HCV remain to be determined. These findings suggest possible regulatory roles for redox and calcium signaling during viral infections.
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Affiliation(s)
- Jinah Choi
- School of Natural Sciences, University of California at Merced, CA 95344, USA.
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Valli MB, Serafino A, Crema A, Bertolini L, Manzin A, Lanzilli G, Bosman C, Iacovacci S, Giunta S, Ponzetto A, Clementi M, Carloni G. Transmission in vitro of hepatitis C virus from persistently infected human B-cells to hepatoma cells by cell-to-cell contact. J Med Virol 2006; 78:192-201. [PMID: 16372297 DOI: 10.1002/jmv.20527] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Virus cell-to-cell spread has been reported for many different viruses and may contribute to pathogenesis of viral disease. The role played by cell-to-cell contact in hepatitis C virus (HCV) transmission was studied in vitro by cell co-cultivation experiments. A human lymphoblastoid B-cell line, infected persistently with HCV in vitro (TO.FE(HCV)), was used as HCV donor [Serafino et al., 2003]; recipient cells were the human hepatoma HepG2 cell line. Both cell types were co-cultured for 48 hr to allow the cell-to-cell contacts. The hepatoma HepG2 cells are not permissive to free-virus infection, but they were infected successfully using TO.FE(HCV) cells as source of virus. The kinetics of viral RNA synthesis and the percentage of infected cells were compared in cell-mediated-and cell-free-viral infection. After co-cultivation, a consistent proportion of hepatoma cells replicated HCV and stably expressed viral antigens. Virus produced was infectious as demonstrated by the ability to reinfect fresh B-cells. This cell model shows that permissiveness to HCV infection can be achieved in vitro in non-permissive hepatoma cells by direct cell-to-cell contacts with infected human B-cells. This mechanism of virus spread may also play a pathogenic role in vivo.
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Affiliation(s)
- Maria Beatrice Valli
- Institute of Neurobiology and Molecular Medicine, National Research Council (CNR), Area di Ricerca CNR TorVergata, Roma, Italy
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15
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Bertolini L, Aebischer ML, Ameglio F, Angeloni A, Delaroche I, Faggioni A, Fruscalzo A, Gorini G, Serafino A, Starace G, Tabilio A. Phenotypic and genotypic characteristics of new euploid–diploid lymphoblastoid B cell lines EBV+, normal human bone marrow derived, spontaneously overgrown in vitro. J Virol Methods 2005; 126:91-100. [PMID: 15847924 DOI: 10.1016/j.jviromet.2005.01.029] [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] [Received: 11/03/2004] [Revised: 01/17/2005] [Accepted: 01/18/2005] [Indexed: 11/13/2022]
Abstract
The present study describes the phenotypic and genotypic features of seven individual growth transformed, euploid-diploid EBV+ human B cell lines arisen spontaneously in vitro. The lines, obtained under general and standard culture conditions (un-manipulated), from seven individual bone marrow samples of 18 healthy young adults, Caucasian, of both sexes, display many traits of normal B cells and represent a mixture of EBV infected latently (latency type III) and producer cells (5-16% VCA+ by immunofluorescence) releasing seven individual different viral strains [Fruscalzo et al., 2001. DNA sequence heterogeneity within the Epstein-Barr virus family of repeats in the latent origin of replication. Gene 265, 165-173] similar to the B95-8 genotype as shown by results of Southern blot of BamHI-digested DNA fragment. These tests were planned to characterize more fully this panel of new bone marrow cell lines sharing normal B cell traits.
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Affiliation(s)
- Luisa Bertolini
- Istituto di Neorobiologia e Medicina Molecolare, CNR, Via del Fosso del Cavaliere, 100, 00133 Rome, Italy.
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16
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Breiman A, Grandvaux N, Lin R, Ottone C, Akira S, Yoneyama M, Fujita T, Hiscott J, Meurs EF. Inhibition of RIG-I-dependent signaling to the interferon pathway during hepatitis C virus expression and restoration of signaling by IKKepsilon. J Virol 2005; 79:3969-78. [PMID: 15767399 PMCID: PMC1061556 DOI: 10.1128/jvi.79.7.3969-3978.2005] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2004] [Accepted: 11/06/2004] [Indexed: 12/22/2022] Open
Abstract
Interferon (IFN) is one important effector of the innate immune response, induced by different viral or bacterial components through Toll-like receptor (TLR)-dependent and -independent mechanisms. As part of its pathogenic strategy, hepatitis C virus (HCV) interferes with the innate immune response and induction of IFN-beta via the HCV NS3/4A protease activity which inhibits phosphorylation of IRF-3, a key transcriptional regulator of the IFN response. In the present study, we demonstrate that inhibition by the protease occurs upstream of the noncanonical IKK-related kinases IKKepsilon and TBK-1, which phosphorylate IRF-3, through partial inhibition of the TLR adapter protein TRIF/TICAM1-dependent pathway. Use of TRIF(-/-) mouse embryo fibroblasts however revealed the presence of a TRIF-independent pathway involved in IFN induction that was also inhibited by NS3/4A. Importantly, we show that NS3/4A can strongly inhibit the ability of the recently described RIG-I protein to activate IFN, suggesting that RIG-I is a key factor in the TRIF-independent, NS3/4A-sensitive pathway. Expression of IFN signaling components including IKKepsilon, TBK-1, TRIF, and wild type or constitutively active forms of RIG-I in the HCV replicon cells resulted in IFN-beta promoter transactivation, with IKKepsilon displaying the highest efficiency. Subsequently, overexpression of IKKepsilon resulted in 80% inhibition of both the positive and negative replicative strands of the HCV replicon. The partial restoration of the capacity of the host cell to transcribe IFN-beta indicates that IKKepsilon expression is able to bypass the HCV-mediated inhibition and restore the innate antiviral response.
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Affiliation(s)
- Adrien Breiman
- Unité Hépacivirus, Institut Pasteur, 75724 Paris Cedex 15, France
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17
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Bartenschlager R, Frese M, Pietschmann T. Novel insights into hepatitis C virus replication and persistence. Adv Virus Res 2005; 63:71-180. [PMID: 15530561 DOI: 10.1016/s0065-3527(04)63002-8] [Citation(s) in RCA: 227] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Hepatitis C virus (HCV) is a small enveloped RNA virus that belongs to the family Flaviviridae. A hallmark of HCV is its high propensity to establish a persistent infection that in many cases leads to chronic liver disease. Molecular studies of the virus became possible with the first successful cloning of its genome in 1989. Since then, the genomic organization has been delineated, and viral proteins have been studied in some detail. In 1999, an efficient cell culture system became available that recapitulates the intracellular part of the HCV life cycle, thereby allowing detailed molecular studies of various aspects of viral RNA replication and persistence. This chapter attempts to summarize the current state of knowledge in these most actively worked on fields of HCV research.
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Affiliation(s)
- Ralf Bartenschlager
- Department of Molecular Virology, University of Heidelberg, Im Neuenheimer Feld 345, 69120 Heidelberg, Germany
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18
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Lam AMI, Rypma RS, Frick DN. Enhanced nucleic acid binding to ATP-bound hepatitis C virus NS3 helicase at low pH activates RNA unwinding. Nucleic Acids Res 2004; 32:4060-70. [PMID: 15289579 PMCID: PMC506820 DOI: 10.1093/nar/gkh743] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The molecular basis of the low-pH activation of the helicase encoded by the hepatitis C virus (HCV) was examined using either a full-length NS3 protein/NS4A cofactor complex or truncated NS3 proteins lacking the protease domain, which were isolated from three different viral genotypes. All proteins unwound RNA and DNA best at pH 6.5, which demonstrate that conserved NS3 helicase domain amino acids are responsible for low-pH enzyme activation. DNA unwinding was less sensitive to pH changes than RNA unwinding. Both the turnover rate of ATP hydrolysis and the K(m) of ATP were similar between pH 6 and 10, but the concentration of nucleic acid needed to stimulate ATP hydrolysis decreased almost 50-fold when the pH was lowered from 7.5 to 6.5. In direct-binding experiments, HCV helicase bound DNA weakly at high pH only in the presence of the non-hydrolyzable ATP analog, ADP(BeF3). These data suggest that a low-pH environment might be required for efficient HCV RNA translation or replication, and support a model in which an acidic residue rotates toward the RNA backbone upon ATP binding repelling nucleic acid from the binding cleft.
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Affiliation(s)
- Angela M I Lam
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA
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Katz J, Cooper EM, Walther RR, Sweeney EW, Dworkin RH. Acute pain in herpes zoster and its impact on health-related quality of life. Clin Infect Dis 2004; 39:342-8. [PMID: 15307000 DOI: 10.1086/421942] [Citation(s) in RCA: 175] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2003] [Accepted: 02/26/2004] [Indexed: 01/30/2023] Open
Abstract
Although the effects of postherpetic neuralgia on physical and emotional functioning have been examined in a number of studies, the impact of acute pain in herpes zoster ("shingles") on health-related quality of life has been neglected. We describe the characteristics of herpes zoster pain and examine its relationship to physical, role, social, and emotional functioning in 110 patients with herpes zoster. When we controlled for relevant covariates, we found that greater pain burden, as assessed by the product of pain intensity and duration, was associated with poorer physical functioning, increased emotional distress, and decreased role and social functioning. The results demonstrate that herpes zoster pain has broad effects on the daily lives of patients and on their emotional health. The increasing incidence of herpes zoster that can be anticipated as the population ages requires that clinical trials that examine interventions to prevent or treat herpes zoster pain be given a high priority.
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Affiliation(s)
- Jennifer Katz
- Department of Anesthesiology, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA
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20
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Choi J, Lee KJ, Zheng Y, Yamaga AK, Lai MMC, Ou JH. Reactive oxygen species suppress hepatitis C virus RNA replication in human hepatoma cells. Hepatology 2004; 39:81-9. [PMID: 14752826 DOI: 10.1002/hep.20001] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Hepatitis C virus (HCV) is a positive-stranded RNA virus that causes severe liver diseases, such as cirrhosis and hepatocellular carcinoma. HCV uses an RNA-dependent RNA polymerase to replicate its genome and an internal ribosomal entry site to translate its proteins. HCV infection is characterized by an increase in the concentrations of reactive oxygen species (ROS), the effect of which on HCV replication has yet to be determined. In this report, we investigated the effect of ROS on HCV replication, using a bicistronic subgenomic RNA replicon and a genomic RNA that can replicate in human hepatoma cells. The treatment with peroxide at concentrations that did not deplete intracellular glutathione or induce cell death resulted in significant decreases in the HCV RNA level in the cells. This response could be partially reversed by the antioxidant N-acetylcysteine. Further studies indicated that such a suppressive response to ROS was not due to the suppression of HCV protein synthesis or the destabilization of HCV RNA. Rather, it occurred rapidly at the level of RNA replication. ROS appeared to disrupt active HCV replication complexes, as they reduced the amount of NS3 and NS5A in the subcellular fraction where active HCV RNA replication complexes were found. In conclusion, our results show that ROS can rapidly inhibit HCV RNA replication in human hepatoma cells. The increased ROS levels in hepatitis C patients may therefore play an important role in the suppression of HCV replication.
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Affiliation(s)
- Jinah Choi
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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