AIM To assess daclatasvir plus asunaprevir(d UAL) in treatment-na?ve patients from China's Mainland, Russia and South Korea with hepatitis C virus(HCV) genotype 1 b infection. METHODS Patients were randomly assign...AIM To assess daclatasvir plus asunaprevir(d UAL) in treatment-na?ve patients from China's Mainland, Russia and South Korea with hepatitis C virus(HCV) genotype 1 b infection. METHODS Patients were randomly assigned(3:1) to receive 24 wk of treatment with d UAL(daclatasvir 60 mg once daily and asunaprevir 100 mg twice daily) beginning on day 1 of the treatment period(immediate treatment arm) or following 12 wk of matching placebo(placebodeferred treatment arm). The primary endpoint was a comparison of sustained virologic response at posttreatment week 12(SVR12) compared with the historical SVR rate for peg-interferon plus ribavirin(70%) among patients in the immediate treatment arm. The first 12 wk of the study were blinded. Safety was assessed in d UAL-treated patients compared with placebo patients during the first 12 wk(doubleblind phase), and during 24 wk of d UAL in both arms combined.RESULTS In total, 207 patients were randomly assigned to immediate(n = 155) or placebo-deferred(n = 52) treatment. Most patients were Asian(86%), female(59%) and aged < 65 years(90%). Among them, 13% had cirrhosis, 32% had IL28 B non-CC genotypes and 53% had baseline HCV RNA levels of ≥ 6 million IU/m L. Among patients in the immediate treatment arm, SVR12 was achieved by 92%(95% confidence interval: 87.2-96.0), which was significantly higher than the historical comparator rate(70%). SVR12 was largely unaffected by cirrhosis(89%), age ≥ 65 years(92%), male sex(90%), baseline HCV RNA ≥ 6 million(89%) or IL28 B non-CC genotypes(96%), although SVR12 was higher among patients without(96%) than among those with(53%) baseline NS5 A resistanceassociated polymorphisms(at L31 or Y93 H). during the double-blind phase, aminotransferase elevations were more common among placebo recipients than among patients receiving d UAL. during 24 wk of d UAL therapy(combined arms), the most common adverse events(≥ 10%) were elevated alanine aminotransferase and upper respiratory tract infection; emergent grade 3-4 laboratory abnormalities were展开更多
TRIM22, a tripartite-motif （TRIM） protein, is upregulated upon interferon alpha （IFNa） administration to hepatitis C virus （HCV）-infected patients. However, the physiological role of TRIM22 upregulation remains ...TRIM22, a tripartite-motif （TRIM） protein, is upregulated upon interferon alpha （IFNa） administration to hepatitis C virus （HCV）-infected patients. However, the physiological role of TRIM22 upregulation remains unclear. Here, we describe a potential antiviral function of TRI M22＇s targeting of the HCV NSSA protein. NS5A is important for HCV replication and for resistance to I FNa therapy. During the first 24 h following the initiation of I FNa treatment, upregulation of TRIM22 in the peripheral blood mononuclear cells （PBMCs） of HCV patients correlated with a decrease in viral titer. This phenomenon was confirmed in the hepatocyte-derived cell line Huh-7, which is highly permissive for HCV infection. TRIM22 over-expression inhibited HCV replication, and Small interfering RNA （siRNA）-mediated knockdown of TRIM22 diminished IFNα-induced anti-HCV function. Furthermore, we determined that TRIM22 ubiquitinates NS5A in a concentration-dependent manner. In summary, our results suggest that TRIM22 upregulation is associated with HCV decline during IFNα treatment and Dlavs an important role in controlling HCV replication in vitro.展开更多
AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Althou...AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Although NS5A has been reported to interact with the HCV RNA- dependent RNA polymerase, NS5B, as well as with many cellular proteins, the function of NS5A in the life cycle of HCV remains unclear. METHODS: HCV quasispecies were studied by clon- ing and sequencing of sequential isolates from patients infected by HCV genotype 1b. Patients were treated by IFN-α2b for 3 mo followed by IFN-α2b alone or com- bined IFN-R therapy for 9 additional months. Patients were categorized intro two groups based on their re- sponse to the treatments: 7 with sustained virological re- sponse (SVR) (quasispecies = 150) and 3 non-respond- ers (NR) to IFN-R (quasispecies = 106). RESULTS: Prior to treatment, SVR patients displayed a lower complexity of quasispecies than NR patients. Most patients had a decrease in the complexity of quasispe- cies during therapy. Analysis of amino acids substitu- tions showed that the degree of the complexity of the interferon sensitivity-determining region (ISDR) and the V3 domain of NS5A protein was able to discriminate thetwo groups of patients. Moreover, SVR patients displayed more variability in the NS5A region than NR patients. CONCLUSION: These results suggest that detailed mo- lecular analysis of the NS5A region may be important for understanding its function in IFN response during HCV 1b infection.展开更多
Present study outlines a comprehensive view of published information about the underlying mechanisms operational for progression of chronic hepatitis C virus(HCV) infection to development of hepatocellular carcinoma(H...Present study outlines a comprehensive view of published information about the underlying mechanisms operational for progression of chronic hepatitis C virus(HCV) infection to development of hepatocellular carcinoma(HCC). These reports are based on the results of animal experiments and human based studies. Although, the exact delineated mechanism is not yet established, there are evidences available to emphasize the involvement of HCV induced chronic inflammation, oxidative stress, insulin resistance, endoplasmic reticulum stress, hepato steatosis and liver fibrosis in the progression of HCV chronic disease to HCC. Persistent infection with replicating HCV not only initiates several liver alterations but also creates an environment for development of liver cancer. Various studies have reported that HCV acts both directly as well as indirectly in promoting this process. Whereas HCV related proteins, like HCV core, E1, E2, NS3 and NS5A, modulate signal pathways dysregulating cell cycle and cell metabolism, the chronic infection produces similar changes in an indirect way. HCV is an RNA virus and does not integrate with host genome and therefore, HCV induced hepatocarcinogenesis pursues a totally different mechanism causing imbalance between suppressors and proto-oncogenes and genomic integrity. However, the exact mechanism of HCC inducement still needs a full understanding of various steps involved in this process.展开更多
The hepatitis C Virus (HCV) presents a high degree of genetic variability which is explained by the combination of a lack of proof reading by the RNA dependant RNA polymerase and a high level of viral replication. The...The hepatitis C Virus (HCV) presents a high degree of genetic variability which is explained by the combination of a lack of proof reading by the RNA dependant RNA polymerase and a high level of viral replication. The re- sulting genetic polymorphism defines a classification in clades, genotypes, subtypes, isolates and quasispecies. This diversity is known to reflect the range of responses to Interferon therapy. The genotype is one of the pre- dictive parameters currently used to define the antiviral treatment strategy and the chance of therapeutic suc- cess. Studies have also reported the potential impact of the viral genetic polymorphism in the outcome of antivi- ral therapy in patients infected by the same HCV geno- type. Both structural and non structural genomic regions of HCV have been suggested to be involved in the Inter- feron pathway and the resistance to antiviral therapy. In this review, we first detail the viral basis of HCV diversity. Then, the HCV genetic regions that may be implicated in resistance to therapy are described, with a focus on the structural region encoded by the E2 gene and the non- structural genes NS3, NS5A and NS5B. Both mechanisms of the Interferon resistance and of the new antiviral drugs are described in this review.展开更多
Over the last decade, the standard of care for the treat- ment of chronic hepatitis C has been the combination of pegylated-interferon-alfa （PEG-IFN） and ribavirin （RBV） which results in sustained virological resp...Over the last decade, the standard of care for the treat- ment of chronic hepatitis C has been the combination of pegylated-interferon-alfa （PEG-IFN） and ribavirin （RBV） which results in sustained virological response （SVR） rates of 75%-85% in patients with genotypes 2 or 3 but only of 40%-50% in patients with genotype 1. Cur- rently, there are rapid and continuous developments of numerous new agents against hepatitis C virus （HCV）, which are the focus of this review. Boceprevir and tela- previr, two first-generation NS3/4A HCV protease inhibi- tors, have been recently licensed in several countries around the world to be used in combination with PEG- IFN and RBV for the treatment of genotype 1 patients. Boceprevir or telaprevir based triple regimens, com- pared with the PEG-IFN/RBV combination, improve the SVR rates by 25%-31% in treatment-naTve genotype 1 patients, by 40%-64% in prior relapsers, by 33%-45% in prior partial responders and by 24%-28% in prior null responders. At the same time, the application of response-guided treatment algorithms according to the on-treatment virological response results in shortening of the total therapy duration to only 24 wk in 45%-55% of treatment-na＇ive patients. There are, however, several challenges with the use of the new triple combinations in genotype 1 patients, such as the need for immediate results of HCV RNA testing using sensitive quantitative assays, new and more frequent adverse events （anemia and dysgeusia for boceprevir; pruritus, rash and anemia for telaprevir）, new drug interactions and increasing dif- ficulties in compliance. Moreover, the SVR rates are still poor in very difficult to treat subgroups of genotype 1 patients, such as null responders with cirrhosis, while there is no benefit for patients who cannot tolerate PEG- IFN/RBV or who are infected with non-1 HCV genotype. Many newer anti-HCV agents of different classes and numerous combinations are currently under evaluation with encouraging results. Preliminary data suggest that展开更多
Full length NS5A gene of the hepatitis C virus was amplified by PCR using plasmid pBAC25 containing HCV nonstructural gene as template. The amplified fragment (about 1.34 kb) was cloned into plasmid pQE32, and the rec...Full length NS5A gene of the hepatitis C virus was amplified by PCR using plasmid pBAC25 containing HCV nonstructural gene as template. The amplified fragment (about 1.34 kb) was cloned into plasmid pQE32, and the recombinant plasmid pQENS5A was expressed in JM109 strain. The NS5A protein was purified by NiSO 4 metal chelating resin, and characterized by Western blot. Its antigenecity was determined by ELISA. The positive detection rate of anti NS5A was 75% (69/92) in ninety two clinic sera. The positive rate of anti NS5A was 82.5% (33/40) in fourty positive standand sera, and the negative rate of anti NS5A was 100% (40/40) in fourty negative standand sera. The results showed that the Full length NS5A proteinn had the higher sensitivity and specificity in the detection of HCV antibody in sera, we suggested that NS5A protein was a useful antigen for blood screening.展开更多
Hepatitis C virus (HCV) infection is a growing public health concern,with 184 million people infected worldwide.During the past decade,interferon has been the backbone of HCV treatment,even though it remains far from ...Hepatitis C virus (HCV) infection is a growing public health concern,with 184 million people infected worldwide.During the past decade,interferon has been the backbone of HCV treatment,even though it remains far from ideal.The latest development of the new direct antivirals has drastically changed the treatment approach for chronic hepatitis C (CHC).Inhibitors of the HCV NS5A region have garnered remarkable interest among treating physicians,due to their high potency and favourable safety profile.In particular,treatment with daclatasvir (DCV) has yielded high rates of vriologic response in patients infected with genotype (Gt) 1 and Gt 3,when used in combination with other antivirals of a different class,such as sofosbuvir.Although few data are available for DCV treatment of the other Gts,the results in patients with Gt 2 and Gt 4 infection appear promising,as do those for unique patient populations.NS5A-resistant viral variants can pre-exist or emerge after treatment failure for the HCV NS5A inhibitors.Nonetheless,DCV-resistant viral variants continue to be sensitive to interferon and other classes of antivirals such as NS3/4A and NS5B inhibitors.Herein,we aimed to provide an overview of the current knowledge about DCV in the treatment of CHC.展开更多
AIM: To evaluate the inhibition effect of HCV NS5A on p53 transactivation on p21 promoter and explore its possible mechanism for influencing p53 function.METHODS: p53 function of transactivation on p21 promoter was st...AIM: To evaluate the inhibition effect of HCV NS5A on p53 transactivation on p21 promoter and explore its possible mechanism for influencing p53 function.METHODS: p53 function of transactivation on p21 promoter was studied with a luciferase reporter system in which the luciferase gene is driven by p21 promoter, and the p53-DNA binding ability was observed with the use of electrophoretic mobility-shift assay (ENSA). Lipofectin mediated p53 or HCV NS5A expression vectors were used to transfecthepatoma cell lines to observe whether HCV NS5A could abrogate the binding ability of p53 to its specific DNA sequence and p53 transactivation on p21 promoter.Western blot experiment was used for detection of HCVNS5A and p53 proteins expression.RESULTS: Relative luciferase activity driven by p21 promoter increased significantly in the presence of endogenous p53 protein. Compared to the control group, exogenous p53 protein also stimulated p21 promoter driven luciferase gene expression in a dose-dependent way. HCV NS5Aprotein gradually inhibited both endogenous andexogenous p53 transactivation on p21 promoter withincrease of the dose of HCV NS5A expression plasmid. By the experiment of ErVlSA, we could find p53 binding to its specific DNA sequence and, when co-transfected with increased dose of HCV NS5A expression vector, the p53binding affinity to its DNA gradually decreased and finally disappeared. Between the Huh 7 cells transfected with p53 expression vector alone or co-transfected with HCV NS5A expression vector, there was no difference in thep53 protein expression.CONCLUSION: HCV NS5A inhibits p53 transactivation onp21 promoter through abrogating p53 binding affinity toits specific DNA sequence. It does not affect p53 proteinexpression.展开更多
AIM： To study the amino acid substitutions in the carboxy （C）-terminal part of E2 protein and in the interferon （IFN） sensitivity determining region （ISDR） and their correlation with response to IFN and viral l...AIM： To study the amino acid substitutions in the carboxy （C）-terminal part of E2 protein and in the interferon （IFN） sensitivity determining region （ISDR） and their correlation with response to IFN and viral load in 85 hepatitis C virus （HCV）-lb-infected patients treated with IFN. METHODS： The C-terminal part of E2 （codons 617-711） including PKR/eIF2α phosphorylation homology domain （PePHD） and ISDR was sequenced in 85 HCV-1b-infected patients treated by IFN monotherapy. RESULTS： The amino acid substitutions in PePHD detected only in 4 of 85 patients were not correlated either with response to iFN or with viral load. The presence of substitutions in a N-terminal variable region （codons 617-641） in the C-terminal part of E2 was significantly correlated with both small viral load （33.9% vs 13.8%, P = 0.0394） and sustained response to iFN （25.0% vs 6.9 %, P = 0.0429）. Four or more substitutions in ISDR were significantly correlated with both small viral load （78.6% vs 16.2%, P 〈 0.0001） and sustained response to iFN （85.7% vs 2.9%, P 〈 0.0001）. In multivariate analysis, ISDR in nonstructural （NS） 5A （OR = 0.39, P 〈 0.0001） and N-terminal variable region （OR = 0.51, P = 0.039） was selected as the independentpredictors for small viral load, and ISDR （OR = 39.0, P 〈 0.0001） was selected as the only independent predictor for sustained response. CONCLUSION： The N-terminal variable region in the C-terminal part of E2 correlates with both response to IFN monotherapy and viral load and is one of the factors independently associated with a small viral load.展开更多
Zika virus (ZIKV), a mosquito-borne flavivirus, has been associated with benign infections for decades. However, it has become a public health concern due to its association with severe fetal and neurological complica...Zika virus (ZIKV), a mosquito-borne flavivirus, has been associated with benign infections for decades. However, it has become a public health concern due to its association with severe fetal and neurological complications. Although many efforts have been made to control ZIKV infection, approved vaccines or antiviral drugs are still lacking. Consequently, the development of new effective anti-ZIKV agents is urgently needed. In this context, we investigated the antiviral potential of pyrazolone derivatives against ZIKV replication using in silico and in vitro methods. The four pyrazolone derivatives evaluated (1a, 1b, 1c, and 1d) inhibited over 50% of ZIKV replication with low cytotoxicity. Among them, compound 1b exhibited the most potent activity (EC50 = 4.3 μM) and the highest selectivity (SI = 342). Mechanism of action studies indicated that these compounds act at early stages of virus replication, and compound 1b can also directly inactivate ZIKV particles. Molecular docking studies suggested that these compounds can bind to and block the activity of ZIKV NS5 methyltransferase. Finally, pharmacokinetic and toxicological predictions have reinforced the safety and drug-like profiles of these derivatives. In conclusion, the pyrazolone scaffold proved to be valuable for anti-ZIKV drug development, and the derivatives studied deserve further investigation.展开更多
Hepatitis C virus(HCV) affects 3% of the world population. It represents the main cause of chronic liver disease and is responsible for extra-hepatic complications, such as type 2 diabetes and cardiovascular diseases....Hepatitis C virus(HCV) affects 3% of the world population. It represents the main cause of chronic liver disease and is responsible for extra-hepatic complications, such as type 2 diabetes and cardiovascular diseases. HCV includes 7 genotypes differing in the nucleotide sequence variability, the geographic distribution, the rates of viral clearance, the risk of progression to liver fibrosis and to hepatocellular carcinoma, and the response to therapy. Last years have seen remarkable advances in the field of HCV infection with the approval of direct antiviral agents(DAAs) targeting key viral proteins involved in the HCV replication. Several oral regimens combining DAAs from different families have been developed and these regimens showed increased and sustained virological response rates to above 90% reducing the treatment duration to 12 wk or less. In particular, sofosbuvir, a nucleotide analogue nonstructural(NS)5B polymerase inhibitor, and velpatasvir, a NS5 A inhibitor, have been tested in two phase 3 trials, the ASTRAL-2(against HCV genotype 2) and the ASTRAL-3(against HCV genotype 3), demonstrating to be effective, safe, and well tolerated in patients who were 18 years of age or older and had at least a 6-mo history of HCV infection with a compensated liver disease.展开更多
文摘AIM To assess daclatasvir plus asunaprevir(d UAL) in treatment-na?ve patients from China's Mainland, Russia and South Korea with hepatitis C virus(HCV) genotype 1 b infection. METHODS Patients were randomly assigned(3:1) to receive 24 wk of treatment with d UAL(daclatasvir 60 mg once daily and asunaprevir 100 mg twice daily) beginning on day 1 of the treatment period(immediate treatment arm) or following 12 wk of matching placebo(placebodeferred treatment arm). The primary endpoint was a comparison of sustained virologic response at posttreatment week 12(SVR12) compared with the historical SVR rate for peg-interferon plus ribavirin(70%) among patients in the immediate treatment arm. The first 12 wk of the study were blinded. Safety was assessed in d UAL-treated patients compared with placebo patients during the first 12 wk(doubleblind phase), and during 24 wk of d UAL in both arms combined.RESULTS In total, 207 patients were randomly assigned to immediate(n = 155) or placebo-deferred(n = 52) treatment. Most patients were Asian(86%), female(59%) and aged < 65 years(90%). Among them, 13% had cirrhosis, 32% had IL28 B non-CC genotypes and 53% had baseline HCV RNA levels of ≥ 6 million IU/m L. Among patients in the immediate treatment arm, SVR12 was achieved by 92%(95% confidence interval: 87.2-96.0), which was significantly higher than the historical comparator rate(70%). SVR12 was largely unaffected by cirrhosis(89%), age ≥ 65 years(92%), male sex(90%), baseline HCV RNA ≥ 6 million(89%) or IL28 B non-CC genotypes(96%), although SVR12 was higher among patients without(96%) than among those with(53%) baseline NS5 A resistanceassociated polymorphisms(at L31 or Y93 H). during the double-blind phase, aminotransferase elevations were more common among placebo recipients than among patients receiving d UAL. during 24 wk of d UAL therapy(combined arms), the most common adverse events(≥ 10%) were elevated alanine aminotransferase and upper respiratory tract infection; emergent grade 3-4 laboratory abnormalities were
文摘TRIM22, a tripartite-motif （TRIM） protein, is upregulated upon interferon alpha （IFNa） administration to hepatitis C virus （HCV）-infected patients. However, the physiological role of TRIM22 upregulation remains unclear. Here, we describe a potential antiviral function of TRI M22＇s targeting of the HCV NSSA protein. NS5A is important for HCV replication and for resistance to I FNa therapy. During the first 24 h following the initiation of I FNa treatment, upregulation of TRIM22 in the peripheral blood mononuclear cells （PBMCs） of HCV patients correlated with a decrease in viral titer. This phenomenon was confirmed in the hepatocyte-derived cell line Huh-7, which is highly permissive for HCV infection. TRIM22 over-expression inhibited HCV replication, and Small interfering RNA （siRNA）-mediated knockdown of TRIM22 diminished IFNα-induced anti-HCV function. Furthermore, we determined that TRIM22 ubiquitinates NS5A in a concentration-dependent manner. In summary, our results suggest that TRIM22 upregulation is associated with HCV decline during IFNα treatment and Dlavs an important role in controlling HCV replication in vitro.
基金Supported by a grant from l’Agence National de la Recherche sur le Sida (ANRS grant 2001/011)
文摘AIM: To evaluate the implication of substitutions in the hepatitis C virus (HCV) non-structural 5A (NS5A) protein in the resistance of HCV during mono-interferon (IFN) or combined IFN-ribavirin (IFN-R) therapy. Although NS5A has been reported to interact with the HCV RNA- dependent RNA polymerase, NS5B, as well as with many cellular proteins, the function of NS5A in the life cycle of HCV remains unclear. METHODS: HCV quasispecies were studied by clon- ing and sequencing of sequential isolates from patients infected by HCV genotype 1b. Patients were treated by IFN-α2b for 3 mo followed by IFN-α2b alone or com- bined IFN-R therapy for 9 additional months. Patients were categorized intro two groups based on their re- sponse to the treatments: 7 with sustained virological re- sponse (SVR) (quasispecies = 150) and 3 non-respond- ers (NR) to IFN-R (quasispecies = 106). RESULTS: Prior to treatment, SVR patients displayed a lower complexity of quasispecies than NR patients. Most patients had a decrease in the complexity of quasispe- cies during therapy. Analysis of amino acids substitu- tions showed that the degree of the complexity of the interferon sensitivity-determining region (ISDR) and the V3 domain of NS5A protein was able to discriminate thetwo groups of patients. Moreover, SVR patients displayed more variability in the NS5A region than NR patients. CONCLUSION: These results suggest that detailed mo- lecular analysis of the NS5A region may be important for understanding its function in IFN response during HCV 1b infection.
文摘Present study outlines a comprehensive view of published information about the underlying mechanisms operational for progression of chronic hepatitis C virus(HCV) infection to development of hepatocellular carcinoma(HCC). These reports are based on the results of animal experiments and human based studies. Although, the exact delineated mechanism is not yet established, there are evidences available to emphasize the involvement of HCV induced chronic inflammation, oxidative stress, insulin resistance, endoplasmic reticulum stress, hepato steatosis and liver fibrosis in the progression of HCV chronic disease to HCC. Persistent infection with replicating HCV not only initiates several liver alterations but also creates an environment for development of liver cancer. Various studies have reported that HCV acts both directly as well as indirectly in promoting this process. Whereas HCV related proteins, like HCV core, E1, E2, NS3 and NS5A, modulate signal pathways dysregulating cell cycle and cell metabolism, the chronic infection produces similar changes in an indirect way. HCV is an RNA virus and does not integrate with host genome and therefore, HCV induced hepatocarcinogenesis pursues a totally different mechanism causing imbalance between suppressors and proto-oncogenes and genomic integrity. However, the exact mechanism of HCC inducement still needs a full understanding of various steps involved in this process.
文摘The hepatitis C Virus (HCV) presents a high degree of genetic variability which is explained by the combination of a lack of proof reading by the RNA dependant RNA polymerase and a high level of viral replication. The re- sulting genetic polymorphism defines a classification in clades, genotypes, subtypes, isolates and quasispecies. This diversity is known to reflect the range of responses to Interferon therapy. The genotype is one of the pre- dictive parameters currently used to define the antiviral treatment strategy and the chance of therapeutic suc- cess. Studies have also reported the potential impact of the viral genetic polymorphism in the outcome of antivi- ral therapy in patients infected by the same HCV geno- type. Both structural and non structural genomic regions of HCV have been suggested to be involved in the Inter- feron pathway and the resistance to antiviral therapy. In this review, we first detail the viral basis of HCV diversity. Then, the HCV genetic regions that may be implicated in resistance to therapy are described, with a focus on the structural region encoded by the E2 gene and the non- structural genes NS3, NS5A and NS5B. Both mechanisms of the Interferon resistance and of the new antiviral drugs are described in this review.
文摘Over the last decade, the standard of care for the treat- ment of chronic hepatitis C has been the combination of pegylated-interferon-alfa （PEG-IFN） and ribavirin （RBV） which results in sustained virological response （SVR） rates of 75%-85% in patients with genotypes 2 or 3 but only of 40%-50% in patients with genotype 1. Cur- rently, there are rapid and continuous developments of numerous new agents against hepatitis C virus （HCV）, which are the focus of this review. Boceprevir and tela- previr, two first-generation NS3/4A HCV protease inhibi- tors, have been recently licensed in several countries around the world to be used in combination with PEG- IFN and RBV for the treatment of genotype 1 patients. Boceprevir or telaprevir based triple regimens, com- pared with the PEG-IFN/RBV combination, improve the SVR rates by 25%-31% in treatment-naTve genotype 1 patients, by 40%-64% in prior relapsers, by 33%-45% in prior partial responders and by 24%-28% in prior null responders. At the same time, the application of response-guided treatment algorithms according to the on-treatment virological response results in shortening of the total therapy duration to only 24 wk in 45%-55% of treatment-na＇ive patients. There are, however, several challenges with the use of the new triple combinations in genotype 1 patients, such as the need for immediate results of HCV RNA testing using sensitive quantitative assays, new and more frequent adverse events （anemia and dysgeusia for boceprevir; pruritus, rash and anemia for telaprevir）, new drug interactions and increasing dif- ficulties in compliance. Moreover, the SVR rates are still poor in very difficult to treat subgroups of genotype 1 patients, such as null responders with cirrhosis, while there is no benefit for patients who cannot tolerate PEG- IFN/RBV or who are infected with non-1 HCV genotype. Many newer anti-HCV agents of different classes and numerous combinations are currently under evaluation with encouraging results. Preliminary data suggest that
文摘Full length NS5A gene of the hepatitis C virus was amplified by PCR using plasmid pBAC25 containing HCV nonstructural gene as template. The amplified fragment (about 1.34 kb) was cloned into plasmid pQE32, and the recombinant plasmid pQENS5A was expressed in JM109 strain. The NS5A protein was purified by NiSO 4 metal chelating resin, and characterized by Western blot. Its antigenecity was determined by ELISA. The positive detection rate of anti NS5A was 75% (69/92) in ninety two clinic sera. The positive rate of anti NS5A was 82.5% (33/40) in fourty positive standand sera, and the negative rate of anti NS5A was 100% (40/40) in fourty negative standand sera. The results showed that the Full length NS5A proteinn had the higher sensitivity and specificity in the detection of HCV antibody in sera, we suggested that NS5A protein was a useful antigen for blood screening.
文摘Hepatitis C virus (HCV) infection is a growing public health concern,with 184 million people infected worldwide.During the past decade,interferon has been the backbone of HCV treatment,even though it remains far from ideal.The latest development of the new direct antivirals has drastically changed the treatment approach for chronic hepatitis C (CHC).Inhibitors of the HCV NS5A region have garnered remarkable interest among treating physicians,due to their high potency and favourable safety profile.In particular,treatment with daclatasvir (DCV) has yielded high rates of vriologic response in patients infected with genotype (Gt) 1 and Gt 3,when used in combination with other antivirals of a different class,such as sofosbuvir.Although few data are available for DCV treatment of the other Gts,the results in patients with Gt 2 and Gt 4 infection appear promising,as do those for unique patient populations.NS5A-resistant viral variants can pre-exist or emerge after treatment failure for the HCV NS5A inhibitors.Nonetheless,DCV-resistant viral variants continue to be sensitive to interferon and other classes of antivirals such as NS3/4A and NS5B inhibitors.Herein,we aimed to provide an overview of the current knowledge about DCV in the treatment of CHC.
基金Supported by the National Natural Science Foundation of China,No.3967067
文摘AIM: To evaluate the inhibition effect of HCV NS5A on p53 transactivation on p21 promoter and explore its possible mechanism for influencing p53 function.METHODS: p53 function of transactivation on p21 promoter was studied with a luciferase reporter system in which the luciferase gene is driven by p21 promoter, and the p53-DNA binding ability was observed with the use of electrophoretic mobility-shift assay (ENSA). Lipofectin mediated p53 or HCV NS5A expression vectors were used to transfecthepatoma cell lines to observe whether HCV NS5A could abrogate the binding ability of p53 to its specific DNA sequence and p53 transactivation on p21 promoter.Western blot experiment was used for detection of HCVNS5A and p53 proteins expression.RESULTS: Relative luciferase activity driven by p21 promoter increased significantly in the presence of endogenous p53 protein. Compared to the control group, exogenous p53 protein also stimulated p21 promoter driven luciferase gene expression in a dose-dependent way. HCV NS5Aprotein gradually inhibited both endogenous andexogenous p53 transactivation on p21 promoter withincrease of the dose of HCV NS5A expression plasmid. By the experiment of ErVlSA, we could find p53 binding to its specific DNA sequence and, when co-transfected with increased dose of HCV NS5A expression vector, the p53binding affinity to its DNA gradually decreased and finally disappeared. Between the Huh 7 cells transfected with p53 expression vector alone or co-transfected with HCV NS5A expression vector, there was no difference in thep53 protein expression.CONCLUSION: HCV NS5A inhibits p53 transactivation onp21 promoter through abrogating p53 binding affinity toits specific DNA sequence. It does not affect p53 proteinexpression.
文摘AIM： To study the amino acid substitutions in the carboxy （C）-terminal part of E2 protein and in the interferon （IFN） sensitivity determining region （ISDR） and their correlation with response to IFN and viral load in 85 hepatitis C virus （HCV）-lb-infected patients treated with IFN. METHODS： The C-terminal part of E2 （codons 617-711） including PKR/eIF2α phosphorylation homology domain （PePHD） and ISDR was sequenced in 85 HCV-1b-infected patients treated by IFN monotherapy. RESULTS： The amino acid substitutions in PePHD detected only in 4 of 85 patients were not correlated either with response to iFN or with viral load. The presence of substitutions in a N-terminal variable region （codons 617-641） in the C-terminal part of E2 was significantly correlated with both small viral load （33.9% vs 13.8%, P = 0.0394） and sustained response to iFN （25.0% vs 6.9 %, P = 0.0429）. Four or more substitutions in ISDR were significantly correlated with both small viral load （78.6% vs 16.2%, P 〈 0.0001） and sustained response to iFN （85.7% vs 2.9%, P 〈 0.0001）. In multivariate analysis, ISDR in nonstructural （NS） 5A （OR = 0.39, P 〈 0.0001） and N-terminal variable region （OR = 0.51, P = 0.039） was selected as the independentpredictors for small viral load, and ISDR （OR = 39.0, P 〈 0.0001） was selected as the only independent predictor for sustained response. CONCLUSION： The N-terminal variable region in the C-terminal part of E2 correlates with both response to IFN monotherapy and viral load and is one of the factors independently associated with a small viral load.
文摘Zika virus (ZIKV), a mosquito-borne flavivirus, has been associated with benign infections for decades. However, it has become a public health concern due to its association with severe fetal and neurological complications. Although many efforts have been made to control ZIKV infection, approved vaccines or antiviral drugs are still lacking. Consequently, the development of new effective anti-ZIKV agents is urgently needed. In this context, we investigated the antiviral potential of pyrazolone derivatives against ZIKV replication using in silico and in vitro methods. The four pyrazolone derivatives evaluated (1a, 1b, 1c, and 1d) inhibited over 50% of ZIKV replication with low cytotoxicity. Among them, compound 1b exhibited the most potent activity (EC50 = 4.3 μM) and the highest selectivity (SI = 342). Mechanism of action studies indicated that these compounds act at early stages of virus replication, and compound 1b can also directly inactivate ZIKV particles. Molecular docking studies suggested that these compounds can bind to and block the activity of ZIKV NS5 methyltransferase. Finally, pharmacokinetic and toxicological predictions have reinforced the safety and drug-like profiles of these derivatives. In conclusion, the pyrazolone scaffold proved to be valuable for anti-ZIKV drug development, and the derivatives studied deserve further investigation.
文摘Hepatitis C virus(HCV) affects 3% of the world population. It represents the main cause of chronic liver disease and is responsible for extra-hepatic complications, such as type 2 diabetes and cardiovascular diseases. HCV includes 7 genotypes differing in the nucleotide sequence variability, the geographic distribution, the rates of viral clearance, the risk of progression to liver fibrosis and to hepatocellular carcinoma, and the response to therapy. Last years have seen remarkable advances in the field of HCV infection with the approval of direct antiviral agents(DAAs) targeting key viral proteins involved in the HCV replication. Several oral regimens combining DAAs from different families have been developed and these regimens showed increased and sustained virological response rates to above 90% reducing the treatment duration to 12 wk or less. In particular, sofosbuvir, a nucleotide analogue nonstructural(NS)5B polymerase inhibitor, and velpatasvir, a NS5 A inhibitor, have been tested in two phase 3 trials, the ASTRAL-2(against HCV genotype 2) and the ASTRAL-3(against HCV genotype 3), demonstrating to be effective, safe, and well tolerated in patients who were 18 years of age or older and had at least a 6-mo history of HCV infection with a compensated liver disease.
