scholarly journals Identification of Hepatitis C Virus Inhibitors Targeting Different Aspects of Infection Using a Cell-Based Assay

2012 ◽  
Vol 56 (12) ◽  
pp. 6109-6120 ◽  
Author(s):  
Xuemei Yu ◽  
Bruno Sainz ◽  
Pavel A. Petukhov ◽  
Susan L. Uprichard

ABSTRACTWith 2 to 3% of the worldwide population chronically infected, hepatitis C virus (HCV) infection continues to be a major health care burden. Unfortunately, current interferon-based treatment options are not effective in all patients and are associated with significant side effects. Consequently, there is an ongoing need to identify and develop new anti-HCV therapies. Toward this goal, we previously developed a cell-based HCV infection assay for antiviral compound screening based on a low-multiplicity-of-infection approach that uniquely allows for the identification of antiviral compounds that target cell culture-derived HCV (HCVcc) at any step of the viral infection cycle. Using this assay, here we report the screening of the NCI Diversity Set II library, containing 1,974 synthesized chemical compounds, and the identification of compounds with specific anti-HCV activity. In combination with toxicity counterscreening, we identified 30 hits from the compound library, 13 of which showed reproducible and dose-dependent inhibition of HCV with mean therapeutic indices (50% cytotoxic concentration [CC50]/50% effective concentration [EC50]) of greater than 6. Using HCV pseudotype and replicon systems of multiple HCV genotypes, as well as infectious HCVcc-based assembly and secretion analysis, we determined that different compounds within this group of candidate inhibitors target different steps of viral infection. The compounds identified not only will serve as biological probes to study and further dissect the biology of viral infection but also should facilitate the development of new anti-HCV therapeutic treatments.

2005 ◽  
Vol 49 (10) ◽  
pp. 4197-4202 ◽  
Author(s):  
Der-Ren Hwang ◽  
Ren-Kuo Lin ◽  
Guang-Zhou Leu ◽  
Tiao-Yin Lin ◽  
Tzu-Wen Lien ◽  
...  

ABSTRACT Chronic hepatitis C virus (HCV) infection is a worldwide health problem causing serious complications, such as liver cirrhosis and hepatoma. Alpha interferon (IFN-α) or its polyethylene glycol-modified form combined with ribavirin is the only recommended therapy. However, an alternative therapy is needed due to the unsatisfactory cure rate of the IFN-based therapy. Using a modified reporter assay based on the HCV subgenomic-replicon system, we found that sodium stibogluconate (SSG), a compound used for leishmania treatment, suppressed HCV replication. We have previously reported that SSG is effective at inhibiting HCV replication in a cell line permissive for HCV infection/replication and in an ex vivo assay using fresh human liver slices obtained from patients infected with HCV (26). In this study, we show that the SSG 50% inhibitory dose for HCV replication is 0.2 to 0.3 mg/ml (equivalent to 345 to 517 μM of Sb) in the HCV subgenomic-replicon system. We also found that SSG and IFN-α exert a strong synergistic anti-HCV effect in both the traditional isobologram analysis and the median effect principle (CalcuSyn analysis). The combination of SSG and IFN-α could sustain the antiviral response better than SSG or IFN-α alone. The results suggest that SSG may be a good drug candidate for use in combination with other therapeutics, such as IFN-α and ribavirin, to treat HCV infection.


2004 ◽  
Vol 48 (10) ◽  
pp. 3944-3953 ◽  
Author(s):  
David B. Olsen ◽  
Anne B. Eldrup ◽  
Linda Bartholomew ◽  
Balkrishen Bhat ◽  
Michele R. Bosserman ◽  
...  

ABSTRACT Improved treatments for chronic hepatitis C virus (HCV) infection are needed due to the suboptimal response rates and deleterious side effects associated with current treatment options. The triphosphates of 2′-C-methyl-adenosine and 2′-C-methyl-guanosine were previously shown to be potent inhibitors of the HCV RNA-dependent RNA polymerase (RdRp) that is responsible for the replication of viral RNA in cells. Here we demonstrate that the inclusion of a 7-deaza modification in a series of purine nucleoside triphosphates results in an increase in inhibitory potency against the HCV RdRp and improved pharmacokinetic properties. Notably, incorporation of the 7-deaza modification into 2′-C-methyl-adenosine results in an inhibitor with a 20-fold-increased potency as the 5′-triphosphate in HCV RdRp assays while maintaining the inhibitory potency of the nucleoside in the bicistronic HCV replicon and with reduced cellular toxicity. In contrast, while 7-deaza-2′-C-methyl-GTP also displays enhanced inhibitory potency in enzyme assays, due to poor cellular penetration and/or metabolism, the nucleoside does not inhibit replication of a bicistronic HCV replicon in cell culture. 7-Deaza-2′-C-methyl-adenosine displays promising in vivo pharmacokinetics in three animal species, as well as an acute oral lethal dose in excess of 2,000 mg/kg of body weight in mice. Taken together, these data demonstrate that 7-deaza-2′-C-methyl-adenosine is an attractive candidate for further investigation as a potential treatment for HCV infection.


2016 ◽  
Vol 91 (2) ◽  
Author(s):  
Fanfan Zhao ◽  
Ting Zhao ◽  
Libin Deng ◽  
Dawei Lv ◽  
Xiaolong Zhang ◽  
...  

ABSTRACT Hepatitis C virus (HCV) infects 2 to 3% of the world population and is a leading cause of liver diseases such as fibrosis, cirrhosis, and hepatocellular carcinoma. Many aspects of HCV study, ranging from molecular virology and antiviral drug development to drug resistance profiling, were supported by straightforward assays of HCV replication and infection. Among these assays, the HCV-dependent fluorescence relocalization (HDFR) system allowed live-cell visualization of infection without modifying the viral genome, but this strategy required careful recognition of the fluorescence relocalization pattern for its high fluorescence background in the cytoplasm. In this study, to achieve background-free visualization of HCV infection, a viral infection-activated split-intein-mediated reporter system (VISI) was devised. Uninfected Huh7.5.1-VISI cells show no background signal, while HCV infection specifically illuminates the nuclei of infected Huh7.5.1-VISI cells with either green fluorescent protein (GFP) or mCherry. Combining VISI-GFP and VISI-mCherry systems, we revisited HCV cell-to-cell transmission with clear-cut distinction of donor and recipient cells in a live-cell manner. Independently of virion assembly, exosomes have been reported to transfer HCV subgenomic RNA to initiate replication in uninfected cells, which suggested an assembly-free pathway. However, our data demonstrated that HCV structural genes and the p7 gene were essential for not only cell-free infectivity but also cell-to-cell transmission. Additionally, depletion of apolipoprotein E (ApoE) from donor cells but not from recipient cells significantly reduced HCV cell-to-cell transmission efficiency. In summary, we developed a background-free cell-based reporter system for convenient live-cell visualization of HCV infection, and our data indicate that complete HCV virion assembly machinery is essential for both cell-free and cell-to-cell transmission. IMPORTANCE Hepatitis C virus (HCV) infects hepatocytes via two pathways: cell-free infection and cell-to-cell transmission. Structural modules of the HCV genome are required for production of infectious cell-free virions; however, the role of specific genes within the structural module in cell-to-cell transmission is not clearly defined. Our data demonstrate that deletion of core, E1E2, and p7 genes individually results in no HCV cell-to-cell transmission and that ApoE knockdown from donor cells causes less-efficient cell-to-cell transmission. Thus, this work indicates that the complete HCV assembly machinery is required for HCV cell-to-cell transmission. At last, this work presents an optimized viral infection-activated split-intein-mediated reporter system for easy live-cell monitoring of HCV infection.


2016 ◽  
Vol 90 (14) ◽  
pp. 6387-6400 ◽  
Author(s):  
Simonetta Bandiera ◽  
Sophie Pernot ◽  
Hussein El Saghire ◽  
Sarah C. Durand ◽  
Christine Thumann ◽  
...  

ABSTRACTHepatitis C virus (HCV)-induced chronic liver disease is a leading cause of hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying HCC development following chronic HCV infection remain poorly understood. MicroRNAs (miRNAs) play an important role in homeostasis within the liver, and deregulation of miRNAs has been associated with liver disease, including HCC. While host miRNAs are essential for HCV replication, viral infection in turn appears to induce alterations of intrahepatic miRNA networks. Although the cross talk between HCV and liver cell miRNAs most likely contributes to liver disease pathogenesis, the functional involvement of miRNAs in HCV-driven hepatocyte injury and HCC remains elusive. Here we combined a hepatocyte-like cell-based model system, high-throughput small RNA sequencing, computational analysis, and functional studies to investigate HCV-miRNA interactions that may contribute to liver disease and HCC. Profiling analyses indicated that HCV infection differentially regulated the expression of 72 miRNAs by at least 2-fold, including miRNAs that were previously described to target genes associated with inflammation, fibrosis, and cancer development. Further investigation demonstrated that the miR-146a-5p level was consistently increased in HCV-infected hepatocyte-like cells and primary human hepatocytes, as well as in liver tissue from HCV-infected patients. Genome-wide microarray and computational analyses indicated that miR-146a-5p overexpression modulates pathways that are related to liver disease and HCC development. Furthermore, we showed that miR-146a-5p has a positive impact on late steps of the viral replication cycle, thereby increasing HCV infection. Collectively, our data indicate that the HCV-induced increase in miR-146a-5p expression both promotes viral infection and is relevant for pathogenesis of liver disease.IMPORTANCEHCV is a leading cause of chronic liver disease and cancer. However, how HCV induces liver cancer remains poorly understood. There is accumulating evidence that a viral cure does not eliminate the risk for HCC development. Thus, there is an unmet medical need to develop novel approaches to predict and prevent virus-induced HCC. miRNA expression is known to be deregulated in liver disease and cancer. Furthermore, miRNAs are essential for HCV replication, and HCV infection alters miRNA expression. However, how miRNAs contribute to HCV-driven pathogenesis remains elusive. Here we show that HCV induces miRNAs that may contribute to liver injury and carcinogenesis. The miR-146a-5p level was consistently increased in different cell-based models of HCV infection and in HCV patient-derived liver tissue. Furthermore, miR-146a-5p increased HCV infection. Collectively, our data are relevant to understanding viral pathogenesis and may open perspectives for novel biomarkers and prevention of virus-induced liver disease and HCC.


2017 ◽  
Vol 26 (2) ◽  
pp. 171-181 ◽  
Author(s):  
Liana Gheorghe ◽  
Ioan Sporea ◽  
Speranţa Iacob ◽  
Roxana Şirli ◽  
Anca Trifan ◽  
...  

Background & Aims: Hepatitis C Virus (HCV) infection is a common condition with endemic prevalence in some areas of the world. In Romania, the mean prevalence is about 3%. New treatments became available on the market in recent years and new drugs are in the pipeline. A re-evaluation of HCV therapy was considered mandatory. The Romanian Society of Gastroenterology and Hepatology undertook this task for the practitioners of this country.Methodology: A group of recognized experts was created who screened the available literature and the major available guidelines. A list of items requiring attention has been created. These items were discussed and rated. Decisions were taken by consensus.Recommendations: We present here the first of the two parts of our Society’s recommendations for chronic HCV infection treatment. An agreement was reached regarding the diagnostic tools, the assessment of severity and the up-dated therapy schedules.Conclusions: This Position Paper represents a guide for the assessment and the therapy of HCV infection. The recommendations are in concordance with other guidelines but are applied to the real-life conditions in this country.Abbreviations: DAAs: Direct-acting antivirals; DDIs: Drug-drug interactions; ESLD: End-stage liver disease; ESRD: End-stage renal disease; eGFR: Estimated glomerular filtration rate; EASL: European Association for the Study of the Liver; EMA: European Medicines Agency; FDA: US Food and Drug Administration; FDC: Fixed-dose combination; GT: Genotype; GRADE: Grading of Recommendations Assessment, Development and Evaluation; HCV: Hepatitis C virus; HCC: Hepatocellular carcinoma; LT: Liver transplantation; LLD: Lower limit of detection; MELD score: Mayo-Clinic End-Stage Liver Disease score; ANMDM: National Agency of Medicines and Medical Devices; PPIs: Proton pump inhibitors; PWID: People who inject drugs; RCT: Randomized controlled trial; RDT: Rapid diagnostic test; RAS: Resistance-associated substitution; SRGH: Romanian Society of Gastroenterology and Hepatology; SAE: serious adverse events; SPC: Summary of Product Characteristics; SVR: Sustained virologic response.


2017 ◽  
Vol 26 (3) ◽  
pp. 309-317 ◽  
Author(s):  
Liana Gheorghe ◽  
Ioan Sporea ◽  
Speranța Iacob ◽  
Roxana Șirli ◽  
Anca Trifan ◽  
...  

Background & Aims: Hepatitis C virus (HCV) infection is a common condition with endemic prevalence in some areas of the world. In Romania, the mean prevalence is about 3%. New treatments have become available on the market in recent years and new drugs are in the pipeline. A re-evaluation of HCV therapy was considered mandatory. The Romanian Society of Gastroenterology and Hepatology undertook this task for the practitioners of this country.Methodology: A group of recognized experts was created who screened the available literature and the major available guidelines. A list of items requiring attention was created and these were discussed and rated. Decisions were taken by consensus.Recommendations: We present here the second part of the Society’s recommendations for chronic HCV infection treatment. An agreement between experts was reached regarding the therapy of the special categories of patients infected with HCV, complications and monitoring of the therapy, follow-up of the patients who reached sustained virologic response and re-treatment of the patients with therapy failure.Conclusions: This Position Paper represents a guide for the assessment and the therapy of HCV infection. The recommendations are in concordance with other guidelines but are applied to real-life conditions in Romania. Abbreviations: CKD: Chronic kidney disease; DAAs: Direct-acting antivirals; DDIs: Drug-drug interactions; ESDL: End-stage liver disease; FCH: Fibrosing cholestatic hepatitis; GT: Genotype; HCV: Hepatitis C virus; HCC: Hepatocellular carcinoma; LT: Liver transplantation; MELD score: Mayo-Clinic End-Stage Liver Disease score; PDC: Premature discontinuation; PWID: Persons who inject drugs; RASs: Resistance associated substitutions; RBV: Ribavirin; RCT: Randomized controlled trial; SAE: Serious adverse events; SRGH: Romanian Society of Gastroenterology and Hepatology; SVR: Sustained virologic response.


2018 ◽  
Vol 9 (06) ◽  
pp. 20251-20256
Author(s):  
Mudassir Khan ◽  
Shahrukh Khan ◽  
Shohra Haider ◽  
Fazal Jalil ◽  
Muhsin Jamal ◽  
...  

Background: Prevalence of Hepatitis C viral infection and its major risk factors has been found out in population of Batkhela, Khyber Pakhtunkhwa, Pakistan by taking number of volunteers from the interested area. HCV prevalence has not been researched in recent time here in this area, so that’s why we contributed. Materials and Methods: Ab rapid test cassette serum/plasma (USA) kit has been used for the mentioned purpose following by ELISA and finally PCR to find out active infection of virus. ICT positive individuals were reconfirmed by ELISA and then ELISA positive samples were carefully investigated by RT-PCR for Hepatitis C Virus. Results: The study population was of 770 volunteers belonging to the mentioned area of research, 453 males and 317 females. The overall prevalence was found to be 5.32% of HCV in Batkhela. This prevalence ratio was 3.12% in males and 2.20 % in females. 3rd generation ELISA was used to refine ICT positive samples which showed that 37 of the ICT positive samples had antibodies detected by ELISA. To find out active HCV infection, ELISA positive samples were refined by real time PCR which showed 2.98% of prevalence of active HCV infection in Batkhela based on HCV RNA in their blood. Principle Conclusion: Overall prevalence was found 5.32%, contaminated reused syringes and blades at Barbour’s shop, blood transfusion, surgical operations and unhygienic food in stalls etc were found significant risk factors for acquiring HCV infection. Body weakness and pale yellow skin color was common symptom in HCV positive volunteers. Safe sexual activities, blood screening before donation and sterilizing surgical equipment’s can protect us from Hepatitis C Virus.


2011 ◽  
Vol 152 (22) ◽  
pp. 876-881
Author(s):  
Alajos Pár

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.


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