scholarly journals Hepatitis C Virus Infection Impairs IRF-7 Translocation and Alpha Interferon Synthesis in Immortalized Human Hepatocytes

2010 ◽  
Vol 84 (21) ◽  
pp. 10991-10998 ◽  
Author(s):  
Amit Raychoudhuri ◽  
Shubham Shrivastava ◽  
Robert Steele ◽  
Srikanta Dash ◽  
Tatsuo Kanda ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Signaling Pathway ◽  
Nuclear Translocation ◽  
Human Hepatocytes ◽  
Hcv Infection ◽  
Oligoadenylate Synthetase ◽  
Downstream Signaling ◽  
Inducible Protein ◽  
Chronic Hcv

ABSTRACT Hepatitis C virus (HCV) establishes chronic infection in a significant number of infected humans, although the mechanisms for chronicity remain largely unknown. We have previously shown that HCV infection in immortalized human hepatocytes (IHH) induces beta interferon (IFN-β) expression (T. Kanda, R. Steele, R. Ray, and R. B. Ray, J. Virol. 81:12375-12381, 2007). However, the regulation of the downstream signaling pathway for IFN-α production by HCV is not clearly understood. In this study, the regulation of the IFN signaling pathway following HCV genotype 1a (clone H77) or genotype 2a (clone JFH1) infection of IHH was examined. HCV infection upregulated expression of total STAT1 but failed to induce phosphorylation and efficient nuclear translocation. Subsequent study revealed that HCV infection induces IFN-stimulated response element activation, as evidenced by upregulation of 2′,5′-oligoadenylate synthetase 1. However, nuclear translocation of IRF-7 was impaired following HCV infection. In HCV-infected IHH, IFN-α expression initially increased (up to 24 h) and then decreased at later time points, and IFN-α-inducible protein 27 was not induced. Interestingly, HCV infection blocked IRF-7 nuclear translocation upon poly(I-C) or IFN-α treatment of IHH. Together, our data suggest that HCV infection enhances STAT1 expression but impairs nuclear translocation of IRF-7 and its downstream molecules. These impairments in the IFN-α signaling pathway may, in part, be responsible for establishment of chronic HCV infection.

scholarly journals Hepatitis C Virus Infection Induces the Beta Interferon Signaling Pathway in Immortalized Human Hepatocytes

2007 ◽  
Vol 81 (22) ◽  
pp. 12375-12381 ◽  
Author(s):  
Tatsuo Kanda ◽  
Robert Steele ◽  
Ranjit Ray ◽  
Ratna B. Ray
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Infection ◽  
Signaling Pathway ◽  
Human Hepatocytes ◽  
Hcv Infection ◽  
Oligoadenylate Synthetase ◽  
Hcv Genotype ◽  
Beta Interferon ◽  
Genotype 1A

ABSTRACT Beta interferon (IFN-β) expression is triggered by double-stranded RNA, a common intermediate in the replication of many viruses including hepatitis C virus (HCV). The recent development of cell culture-grown HCV allowed us to analyze the IFN signaling pathway following virus infection. In this study, we have examined the IFN-β signaling pathway following infection of immortalized human hepatocytes (IHH) with HCV genotype 1a (clone H77) or 2a (clone JFH1). We observed that IHH possesses a functional Toll-like receptor 3 pathway. HCV infection in IHH enhanced IFN-β and IFN-stimulated gene 56 (ISG56) promoter activities; however, poly(I-C)-induced IFN-β and ISG56 expression levels were modestly inhibited upon HCV infection. IHH infected with HCV (genotype 1a or 2a) exhibited various levels of translocation of IRF-3 into the nucleus. The upregulation of endogenous IFN-β and 2′,5′-oligoadenylate synthetase 1 mRNA expression was also observed in HCV-infected IHH. Subsequent studies suggested that HCV infection in IHH enhanced STAT1 and ISG56 protein expression. A functional antiviral response of HCV-infected IHH was observed by the growth-inhibitory role in vesicular stomatitis virus. Together, our results suggested that HCV infection in IHH induces the IFN signaling pathway, which corroborates observations from natural HCV infection in humans.

scholarly journals Hepatitis C Virus-Mediated Enhancement of MicroRNA miR-373 Impairs the JAK/STAT Signaling Pathway

2015 ◽  
Vol 89 (6) ◽  
pp. 3356-3365 ◽  
Author(s):  
Anupam Mukherjee ◽  
Adrian M. Di Bisceglie ◽  
Ratna B. Ray
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Signaling Pathway ◽  
Human Hepatocytes ◽  
Hcv Infection ◽  
Janus Kinase ◽  
Hcv Rna ◽  
Type I ◽  
Primary Human Hepatocytes

ABSTRACTHepatitis C virus (HCV) is a serious global health problem and establishes chronic infection in a significant number of infected humans worldwide. Interferon (IFN) and IFN-stimulated genes (ISGs) are amplified during HCV infection but fail to eliminate virus from the liver in a large number of infected patients, and the mechanism is not fully understood. MicroRNAs (miRNAs) have been implicated in the control of many biological processes, including IFN signaling. To gain more insights into the role of cellular miRNAs in possible countermeasures of HCV for suppression of the host antiviral response, a miRNA array was performed by using primary human hepatocytes infected within vitrocell culture-grown HCV. A group of miRNAs were modulated in HCV-infected primary human hepatocytes. We focused on miR-373, as this miRNA was significantly upregulated in HCV-infected primary human hepatocytes. Here, we analyzed the function of miR-373 in the context of HCV infection. HCV infection upregulates miR-373 expression in hepatocytes and HCV-infected liver biopsy specimens. Furthermore, we discovered that miR-373 directly targets Janus kinase 1 (JAK1) and IFN-regulating factor 9 (IRF9), important factors in the IFN signaling pathway. The upregulation of miR-373 by HCV also inhibited STAT1 phosphorylation, which is involved in ISG factor 3 (ISGF3) complex formation and ISG expression. The knockdown of miR-373 in hepatocytes enhanced JAK1 and IRF9 expression and reduced HCV RNA replication. Taken together, our results demonstrated that miR-373 is upregulated during HCV infection and negatively regulated the type I IFN signaling pathway by suppressing JAK1 and IRF9. Our results offer a potential therapeutic approach for antiviral intervention.IMPORTANCEChronic HCV infection is one of the major causes of end-stage liver disease worldwide. Although the recent introduction of direct-acting antiviral (DAA) therapy is extremely encouraging, some infected individuals do not respond to this therapy. Furthermore, these drugs target HCV nonstructural proteins, and with selective pressure, the virus may develop a resistant strain. Therefore, understanding the impairment of IFN signals will help in designing additional therapeutic modalities. In this study, we provide evidence of HCV-mediated upregulation of miR-373 and show that miR-373 impairs IFN signaling by targeting JAK1/IRF9 molecules. The knockdown of miR-373 inhibited HCV replication by upregulating interferon-stimulating gene expression. Together, these results provided new mechanistic insights into the role of miR-373 in HCV infection and suggest a new potential target against HCV infection.

Genetic polymorphisms as the predictors of response to antiviral treatment in chronic hepatitis C virus infection

2011 ◽  
Vol 152 (22) ◽  
pp. 876-881
Author(s):  
Alajos Pár
Keyword(s):  
Chronic Hepatitis ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Genetic Polymorphisms ◽  
Chronic Hepatitis C ◽  
Genome Wide Association Study ◽  
Antiviral Treatment ◽  
Hcv Infection ◽  
Snp Analysis ◽  
Chronic Hcv

The review discusses the genetic polymorphisms involved in the pathogenesis of hepatitis C virus (HCV) infection, that may determine the outcome of disease. In this field earlier both certain major histocompatibility complex (MHC) alleles and some cytokine gene variants have also been studied. Recently, the genome-wide association study (GWAS) and targeted single nucleotide polymorphism (SNP) analysis have revealed that a variant in the promoter region of interleukin-28B (IL-28B) gene is strongly linked to viral clearance and it may be the strongest pretreatment predictor of treatment response in chronic hepatitis C. Last year it was shown that two genetic variants leading to inosine triphosphatase deficiency protect against haemolytic anemia in patients receiving ribavirin during antiviral treatment for chronic HCV infection. Orv. Hetil., 2011, 152, 876–881.

scholarly journals Identification of Keratin 23 as a Hepatitis C Virus-Induced Host Factor in the Human Liver

Cells ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 610 ◽  
Author(s):  
Volker Kinast ◽  
Stefan L. Leber ◽  
Richard J. P. Brown ◽  
Gabrielle Vieyres ◽  
Patrick Behrendt ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Liver Disease ◽  
Hepatitis C ◽  
Ectopic Expression ◽  
Host Factor ◽  
Hcv Infection ◽  
Mrna Levels ◽  
Structural Support ◽  
Protein Levels ◽  
Inducible Protein

Keratin proteins form intermediate filaments, which provide structural support for many tissues. Multiple keratin family members are reported to be associated with the progression of liver disease of multiple etiologies. For example, keratin 23 (KRT23) was reported as a stress-inducible protein, whose expression levels correlate with the severity of liver disease. Hepatitis C virus (HCV) is a human pathogen that causes chronic liver diseases including fibrosis, cirrhosis, and hepatocellular carcinoma. However, a link between KRT23 and hepatitis C virus (HCV) infection has not been reported previously. In this study, we investigated KRT23 mRNA levels in datasets from liver biopsies of chronic hepatitis C (CHC) patients and in primary human hepatocytes experimentally infected with HCV, in addition to hepatoma cells. Interestingly, in each of these specimens, we observed an HCV-dependent increase of mRNA levels. Importantly, the KRT23 protein levels in patient plasma decreased upon viral clearance. Ectopic expression of KRT23 enhanced HCV infection; however, CRIPSPR/Cas9-mediated knockout did not show altered replication efficiency. Taken together, our study identifies KRT23 as a novel, virus-induced host-factor for hepatitis C virus.

scholarly journals Proteasome Activator PA28γ-Dependent Nuclear Retention and Degradation of Hepatitis C Virus Core Protein

2003 ◽  
Vol 77 (19) ◽  
pp. 10237-10249 ◽  
Author(s):  
Kohji Moriishi ◽  
Tamaki Okabayashi ◽  
Kousuke Nakai ◽  
Kyoji Moriya ◽  
Kazuhiko Koike ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Core Protein ◽  
Regulatory Protein ◽  
Hcv Infection ◽  
Nuclear Retention ◽  
Proteasome Activator ◽  
Hcv Core Protein ◽  
Core Proteins ◽  
Chronic Hcv

ABSTRACT Hepatitis C virus (HCV) core protein plays an important role in the formation of the viral nucleocapsid and a regulatory protein involved in hepatocarcinogenesis. In this study, we have identified proteasome activator PA28γ (11S regulator γ) as an HCV core binding protein by using yeast two-hybrid system. This interaction was demonstrated not only in cell culture but also in the livers of HCV core transgenic mice. These findings are extended to human HCV infection by the observation of this interaction in liver specimens from a patient with chronic HCV infection. Neither the interaction of HCV core protein with other PA28 subtypes nor that of PA28γ with other Flavivirus core proteins was detected. Deletion of the PA28γ-binding region from the HCV core protein or knockout of the PA28γ gene led to the export of the HCV core protein from the nucleus to the cytoplasm. Overexpression of PA28γ enhanced the proteolysis of the HCV core protein. Thus, the nuclear retention and stability of the HCV core protein is regulated via a PA28γ-dependent pathway through which HCV pathogenesis may be exerted.

Direct-acting Antivirals for Hepatitis C Virus in Patients on Maintenance Dialysis

2017 ◽  
Vol 40 (10) ◽  
pp. 531-541 ◽  
Author(s):  
Fabrizio Fabrizi ◽  
Francesca M. Donato ◽  
Piergiorgio Messa
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Severe Renal Impairment ◽  
Controlled Trial ◽  
Hcv Infection ◽  
Direct Acting Antivirals ◽  
Safety And Efficacy ◽  
Maintenance Dialysis ◽  
Chronic Hcv ◽  
Direct Acting

The frequency of hepatitis C virus (HCV) infection remains high in patients with chronic kidney disease (CKD) and plays a detrimental role in mortality in this population. According to the latest survey, the adjusted hazard ratio for HCV-positive versus HCV-negative patients on long-term dialysis was 1.12 (95% CI, 1.05 to 1.20) and 1.10 (95% CI, 0.98 to 1.22) for all-cause and cardiovascular mortality, respectively. An impairment on quality of life has also been documented in HCV-infected patients undergoing regular dialysis. Most clinicians have been so far reluctant to treat hepatitis C in patients with advanced CKD, due to concerns regarding low efficacy and safety of interferon-based regimens. The advent of all-oral, direct-acting antivirals (DAAs) has revolutionized treatment paradigms for HCV, including patients with other comorbidities such as CKD. Two combinations of DAAs have been recently approved for the treatment of HCV in advanced CKD: elbasvir/grazoprevir (evaluated in 1 randomized controlled trial) and ombitasvir/paritaprevir/ritonavir/dasabuvir with or without ribavirin (examined in some observational, single-arm studies). These antiviral combinations have provided high safety and efficacy (SVR12 rates >90%) in HCV-infected patients with stage 4–5 CKD. Sofosbuvir, a nucleotide analogue inhibitor of the HCV NS5B polymerase, is the cornerstone of most anti-HCV current regimens but is not currently recommended for patients with severe renal insufficiency (eGFR <30 mL/min per 1.73 m2). However, several small-sized studies have been published on the safety and efficacy of sofosbuvir-based regimens for patients with hepatitis C on maintenance dialysis>; overall, the viral response was satisfactory (SVR12 rates ranging between 58% and 100%) with a few drug-related drop-outs. Studies are in progress to assess whether ribavirin-free antiviral combinations with novel DAAs are a viable option for patients with severe renal impairment and chronic HCV infection.

IgM and IgA antibodies generated against hepatitis C virus core antigen in patients with acute and chronic HCV infection

1994 ◽  
Vol 39 (9) ◽  
pp. 2022-2031 ◽  
Author(s):  
Shinjiro Sato ◽  
Shigetoshi Fujiyama ◽  
Motohiko Tanaka ◽  
Masafumi Goto ◽  
Yuko Taura ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hcv Infection ◽  
Core Antigen ◽  
Virus Core ◽  
Iga Antibodies ◽  
Chronic Hcv Infection ◽  
Chronic Hcv

scholarly journals Toll-Like Receptor 3 Mediates Establishment of an Antiviral State against Hepatitis C Virus in Hepatoma Cells

2009 ◽  
Vol 83 (19) ◽  
pp. 9824-9834 ◽  
Author(s):  
Nan Wang ◽  
Yuqiong Liang ◽  
Santhana Devaraj ◽  
Jie Wang ◽  
Stanley M. Lemon ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Hepatitis Virus ◽  
Hepatoma Cells ◽  
Human Hepatocytes ◽  
Hcv Infection ◽  
Type I Interferons ◽  
Type I ◽  
Toll Like Receptor ◽  
Virus Infections

ABSTRACT Toll-like receptor-3 (TLR3) senses double-stranded RNA, initiating signaling that activates NF-κB and interferon regulatory factor 3 (IRF-3), thereby inducing the synthesis of proinflammatory cytokines, type I interferons, and numerous interferon-stimulated genes (ISGs). This pathway has not been extensively investigated in human hepatocytes, and its role in sensing and protecting against hepatitis virus infections is uncertain. We show here that primary human hepatocytes express TLR3 and robustly upregulate ISGs upon poly(I·C) stimulation. We also show that TLR3 senses hepatitis C virus (HCV) infection when expressed in permissive hepatoma cells, acting independently of retinoic acid-inducible gene I and inducing IRF-3 activation and the synthesis of ISGs that restrict virus replication. In turn, HCV infection reduces the abundance of TRIF, an essential TLR3 adaptor, and impairs poly(I·C)-induced signaling. The induction and disruption of TLR3 signaling by HCV may be important factors in determining the outcome of infection and the ability of HCV to establish persistent infections.

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