scholarly journals Inhibition of Hepatitis C Virus Replication by Antimonial Compounds

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.

2009 ◽  
Vol 83 (11) ◽  
pp. 5693-5707 ◽  
Author(s):  
Hua Liang ◽  
Rodney S. Russell ◽  
Nicole L. Yonkers ◽  
David McDonald ◽  
Benigno Rodriguez ◽  
...  

ABSTRACT Dendritic cells (DCs) are reported to be functionally deficient during chronic hepatitis C virus (HCV) infection. Differing results have been reported on direct effects of intact replicative-form HCV on DC function. To better understand the effect of HCV on DC function, we treated freshly purified human myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) with HCV JFH1. We found that HCV upregulated mDC maturation marker (CD83, CD86, and CD40) expression and did not inhibit Toll-like receptor 3 (TLR3) ligand [poly(I:C)]-induced mDC maturation, a finding consistent with the phenotype of DCs from HCV-infected subjects. At the same time, HCV JFH1 inhibited the ability of poly(I:C)-treated mDCs to activate naive CD4 T cells. In contrast, although there was no direct effect of virus on pDC maturation, HCV JFH1 inhibited TLR7 ligand (R848)-induced pDC CD40 expression, and this was associated with impaired ability to activate naive CD4 T cells. Parallel experiments with recombinant HCV proteins indicated HCV core protein may be responsible for a portion of the activity. Furthermore, HCV-mediated mDC maturation was dependent upon CD81-E2 interaction and, in part, TLR2. Using UV-treated HCV, we show that HCV-mediated mDC and pDC maturation is virus replication independent and, using strand specific PCR, we found no evidence for HCV replication within DCs. Because these effects of HCV on DC subset maturation and function in part recapitulate direct ex vivo analysis of DCs in chronic HCV infection, the mechanisms described here likely account for a portion of the DC subset defects observed in vivo.


2002 ◽  
Vol 293 (3) ◽  
pp. 993-999 ◽  
Author(s):  
Hiroe Kishine ◽  
Kazuo Sugiyama ◽  
Makoto Hijikata ◽  
Nobuyuki Kato ◽  
Hitoshi Takahashi ◽  
...  

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.


2002 ◽  
Vol 76 (23) ◽  
pp. 12001-12007 ◽  
Author(s):  
Naushad Ali ◽  
Keith D. Tardif ◽  
Aleem Siddiqui

ABSTRACT The hepatitis C virus (HCV) contains a plus-strand RNA genome. The 5′ noncoding region (NCR) of the viral genome functions as an internal ribosome entry site, and its unique 3′ NCR is required for the assembly of the replication complex during initiation of HCV RNA replication. Lohmann et al. (V. Lohmann, F. Korner, J.-O. Koch, U. Herian, L. Theilman, and R. Batenschlager, Science 285:110-113, 1999) developed a subgenomic HCV replicon system, which represents an important tool in studying HCV replication in cultured cells. In this study, we describe a cell-free replication system that utilizes cytoplasmic lysates prepared from Huh-7 cells harboring the HCV subgenomic replicons. These lysates, which contain ribonucleoprotein complexes associated with cellular membranes, were capable of incorporating [α32P]CTP into newly synthesized RNA from subgenomic replicons in vitro. Replicative forms (RFs) and replicative intermediates (RIs) were synthesized from the endogenous HCV RNA templates. Consistent with previous observations, RFs were found to be resistant to RNase A digestion, whereas RIs were sensitive to RNase treatment. The radiolabeled HCV RF-RI complexes contained both minus and plus strands and were specific to the lysates derived from replicon-expressing cells. The availability of a cell-free replication system offers opportunities to probe the mechanism(s) of HCV replication. It also provides a novel assay for potential therapeutic agents.


2012 ◽  
Vol 86 (16) ◽  
pp. 8740-8749 ◽  
Author(s):  
Gemma Pérez-Vilaró ◽  
Nicoletta Scheller ◽  
Verónica Saludes ◽  
Juana Díez

Processing bodies (P-bodies) are highly dynamic cytoplasmic granules conserved among eukaryotes. They are present under normal growth conditions and contain translationally repressed mRNAs together with proteins from the mRNA decay and microRNA (miRNA) machineries. We have previously shown that the core P-body components PatL1, LSm1, and DDX6 (Rck/p54) are required for hepatitis C virus (HCV) RNA replication; however, how HCV infection affects P-body granules and whether P-body granulesper seinfluence the HCV life cycle remain unresolved issues. Here we show that HCV infection alters P-body composition by specifically changing the localization pattern of P-body components that are required for HCV replication. This effect was not related to an altered expression level of these components and could be reversed by inhibiting HCV replication with a polymerase inhibitor. Similar observations were obtained with a subgenomic replicon that supports only HCV translation and replication, indicating that these early steps of the HCV life cycle trigger the P-body alterations. Finally, P-body disruption by Rap55 depletion did not affect viral titers or HCV protein levels, demonstrating that the localization of PatL1, LSm1, and DDX6 in P-bodies is not required for their function on HCV. Thus, the HCV-induced changes on P-bodies are mechanistically linked to the function of specific P-body components in HCV RNA translation and replication; however, the formation of P-body granules is not required for HCV infection.


2005 ◽  
Vol 79 (21) ◽  
pp. 13473-13482 ◽  
Author(s):  
Itsuki Hamamoto ◽  
Yorihiro Nishimura ◽  
Toru Okamoto ◽  
Hideki Aizaki ◽  
Minyi Liu ◽  
...  

ABSTRACT The hepatitis C virus (HCV) nonstructural protein (NS) 5A is a phosphoprotein that associates with various cellular proteins and participates in the replication of the HCV genome. Human vesicle-associated membrane protein-associated protein (VAP) subtype A (VAP-A) is known to be a host factor essential for HCV replication by binding to both NS5A and NS5B. To obtain more information on the NS5A protein in HCV replication, we screened human brain and liver libraries by a yeast two-hybrid system using NS5A as bait and identified VAP-B as an NS5A-binding protein. Immunoprecipitation and mutation analyses revealed that VAP-B binds to both NS5A and NS5B in mammalian cells and forms homo- and heterodimers with VAP-A. VAP-A interacts with VAP-B through the transmembrane domain. NS5A interacts with the coiled-coil domain of VAP-B via 70 residues in the N-terminal and 341 to 344 amino acids in the C-terminal polyproline cluster region. NS5A was colocalized with VAP-B in the endoplasmic reticulum and Golgi apparatus. The specific antibody to VAP-B suppressed HCV RNA replication in a cell-free assay. Overexpression of VAP-B, but not of a mutant lacking its transmembrane domain, enhanced the expression of NS5A and NS5B and the replication of HCV RNA in Huh-7 cells harboring a subgenomic replicon. In the HCV replicon cells, the knockdown of endogenous VAP-B by small interfering RNA decreased expression of NS5B, but not of NS5A. These results suggest that VAP-B, in addition to VAP-A, plays an important role in the replication of the HCV genome.


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.


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