Chronic delta hepatitis is the most severe form of viral hepatitis affecting nearly 65 million people worldwide.Individuals with this devastating illness are at higher risk for developing cirrhosis and hepatocellular ...Chronic delta hepatitis is the most severe form of viral hepatitis affecting nearly 65 million people worldwide.Individuals with this devastating illness are at higher risk for developing cirrhosis and hepatocellular carcinoma.Delta virus is a defective RNA virus that requires hepatitis B surface antigen for propagation in humans.Infection can occur in the form of a co-infection with hepatitis B,which can be self-limiting,vs superinfection in a patient with established hepatitis B infection,which often leads to chronicity in majority of cases.Current noninvasive tools to assess for advanced liver disease have limited utility in delta hepatitis.Guidelines recommend treatment with pegylated interferon,but this is limited to patients with compensated disease and is efficacious in about 30%of those treated.Due to limited treatment options,novel agents are being investigated and include entry,assembly and export inhibitors of viral particles in addition to stimulators of the host immune response.Future clinical trials should take into consideration the interaction of hepatitis B and hepatitis D as suppression of one virus can lead to the activation of the other.Also,surrogate markers of treatment efficacy have been proposed.展开更多
Hepatitis D virus(HDV) is the smallest single stranded RNA virus infecting humans. The hepatitis B surface antigen envelope protein protects the HDV nucleocapsidantigen and provides a means for the virus to enter and ...Hepatitis D virus(HDV) is the smallest single stranded RNA virus infecting humans. The hepatitis B surface antigen envelope protein protects the HDV nucleocapsidantigen and provides a means for the virus to enter and exit the hepatocyte. Hepatitis B and D viruses exploit the human sodium taurocholate co-transporting polypeptide(NTCP), a receptor, for their entry into hepatocytes. Prenylation of the large delta antigen is a critical determinant of HDV particle assembly. Treatment with pegylated interferon results in sustained virological response six months post-treatment in one fourth of the patients. Nucleos(t)ide analogs(NAs) have been widely tested in hepatitis delta, but they appear to be ineffective. Combination treatment of NAs with interferon also proved to be disappointing so there is a need for novel therapeutic options. The receptor function of NTCP is blocked by Myrcludex B, a synthetic N-acylated pre S1 lipopeptide that competes with infectious virions for receptor binding. There are already some approved drugs available, including irbesartan, ezetimibe, and ritonavir and cyclosporin A, with documented inhibitory effects on NTCP's metabolic function. These drugs may have a role in HDV treatment. Interference with hostmediated post-translational changes of proteins that are crucial to the HDV life cycle, such as prenylation may become an important tool to control HDV infection and prevent replication. Lonafarnib, a prenylation inhibitor significantly reduces virus levels in hepatitis delta patients. Antisense oligodeoxynucleotides which are complementary to genomic HDV ribozyme self-cleavage site and stem?Ⅰ?regions can inhibit genomic HDV ribozyme activity.展开更多
Hepatitis D virus(HDV) is a defective RNA virus which requires the help of hepatitis B virus(HBV) virus for its replication and assembly of new virions. HDV genome contains only one actively transcribed open reading f...Hepatitis D virus(HDV) is a defective RNA virus which requires the help of hepatitis B virus(HBV) virus for its replication and assembly of new virions. HDV genome contains only one actively transcribed open reading frame which encodes for two isoforms of hepatitis delta antigen. Post-translational modifications of small and large delta antigens(S-HDAg and L-HDAg) involving phosphorylation and isoprenylation respectively con- fer these antigens their specific properties. S-HDAg is required for the initiation of the viral genome replica- tion, whereas L-HDAg serves as a principal inhibitor of replication and is essential for the assembly of new virion particles. Immune mediation has usually been implicated in HDV-associated liver damage. The patho- genesis of HDV mainly involves interferon-α signaling inhibition, HDV-specific T-lymphocyte activation and cytokine responses, and tumor necrosis factor-alpha and nuclear factor kappa B signaling. Due to limited protein coding capacity, HDV makes use of host cel- lular proteins to accomplish their life cycle processes, including transcription, replication, post-transcriptional and translational modifications. This intimate host- pathogen interaction significantly alters cell proteome and is associated with an augmented expression of pro-inflammatory, growth and anti-apoptotic factorswhich explains severe necroinflammation and increased cell survival and an early progression to hepatocellular carcinoma in HDV patients. The understanding of the process of viral replication, HBV-HDV interactions, and etio-pathogenesis of the severe course of HDV infection is helpful in identifying the potential therapeutic targets in the virus life cycle for the prophylaxis and treatment of HDV infection and complications.展开更多
Hepatitis delta virus(HDV) seems to strongly suppress hepatitis B virus(HBV)replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, res...Hepatitis delta virus(HDV) seems to strongly suppress hepatitis B virus(HBV)replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, resulting in viral quasispecies. Next-generation sequencing is a viable approach for analyzing the composition of these mutant spectra. As the regulatory hepatitis B X protein(HBx) is essential for HBV replication, determination of HBV X gene(HBX)quasispecies complexity in HBV/HDV infection compared to HBV monoinfection may provide information on the interactions between these two viruses.AIM To compare HBV quasispecies complexity in the HBX 5' region between chronic hepatitis delta(CHD) and chronic HBV mono-infected patients.METHODS Twenty-four untreated patients were included: 7/24(29.2%) with HBeAgnegative chronic HBV infection(CI, previously termed inactive carriers), 8/24(33.3%) with HBeAg-negative chronic hepatitis B(CHB) and 9/24(37.5%) with CHD. A serum sample from each patient was first tested for HBV DNA levels.The HBX 5' region [nucleotides(nt) 1255-1611] was then PCR-amplified for subsequent next-generation sequencing(MiSeq, Illumina, United States). HBV quasispecies complexity in the region analyzed was evaluated using incidencebased indices(number of haplotypes and number of mutations), abundancebased indices(Hill numbers of order 1 and 2), and functional indices(mutation frequency and nucleotide diversity). We also evaluated the pattern of nucleotide changes to investigate which of them could be the cause of the quasispecies complexity.RESULTS CHB patients showed higher median HBV-DNA levels [5.4 logIU/mL,interquartile range(IQR) 3.5-7.9] than CHD(3.4 logIU/mL, IQR 3-7.6)(P = n.s.)or CI(3.2 logIU/mL, IQR 2.3-3.5)(P < 0.01) patients. The incidence and abundance indices indicated that HBV quasispecies complexity was significantly greater in CI than CHB. A similar trend was observed in CHD patients, although only Hill numbers of order 2 showed statistically significant differences(CHB2.81, I展开更多
Hepatitis delta virus(HDV) is the etiologic agent of the most severe form of virus hepatitis in humans. Sharing some structural and functional properties with plant viroids, the HDV RNA contains a single open reading ...Hepatitis delta virus(HDV) is the etiologic agent of the most severe form of virus hepatitis in humans. Sharing some structural and functional properties with plant viroids, the HDV RNA contains a single open reading frame coding for the only virus protein, the Delta antigen. A number of unique features, including ribozyme activity, RNA editing, rolling-circle RNA replication, and redirection for a RNA template of host DNA-dependent RNA polymerase Ⅱ, make this small pathogen an excellent model to study virus-cell interactions and RNA biology. Treatment options for chronic hepatitis Delta are scarce and ineffective. The disease burden is perhaps largely underestimated making the search for new, specific drugs, targets, and treatment strategies an important public health challenge. In this review we address the main features of virus structure, replication, and interaction with the host. Virus pathogenicity and current treatment options are discussed in the light of recent developments.展开更多
目的了解丁型肝炎病毒（hepatitis delta virus，HDV）感染标志物在乙型肝炎病毒（hepatitis B virus，HBV）感染者中的分布状况并分析其临床意义。方法收集HBV感染者的临床资料和血清样本，通过酶联免疫分析法检测其血清HBV感染五项指...目的了解丁型肝炎病毒（hepatitis delta virus，HDV）感染标志物在乙型肝炎病毒（hepatitis B virus，HBV）感染者中的分布状况并分析其临床意义。方法收集HBV感染者的临床资料和血清样本，通过酶联免疫分析法检测其血清HBV感染五项指标、HDVAg和Anti—HDV，结合临床诊断和生化指标进行分析。结果收集HBV感染者样本462例，其中无症状携带者210例，慢性肝炎175例，急性乙肝35例，肝纤维化42例，检出HDV感染率为4．8％，男性显著高于女性，肝纤维化组的HDV感染率最高，为9．5％，其次为慢性肝炎的6．9％，45—60岁人群的HDV感染率为7．8％，显著高于其他年龄段。结论慢性乙肝和肝纤维化病例的HDV感染显著增高，提示HDV感染与肝病的严重程度相关，建议对肝病患者开展血清HDV感染标志物检查，鉴别是否存在HDV重叠感染。展开更多
Egypt has one of the highest prevalence rates of hepatitis C virus(HCV) in the world,mostly with genotype 4 that is highly associated with severe fibrosis. As a consequence,hepatocellular carcinoma has become the lead...Egypt has one of the highest prevalence rates of hepatitis C virus(HCV) in the world,mostly with genotype 4 that is highly associated with severe fibrosis. As a consequence,hepatocellular carcinoma has become the leading cause of cancer in this country. Mauritania is a highly endemic area for hepatitis B virus(HBV). HBV and HCV could both be iatrogenically transmitted through infected blood products,infected needles,and medical equipment improperly sterilized. Adequate and efficient healthcare and public health measures with good surveillance programs,access for screening,prevention strategies,and successful treatment are needed to halt the spread of these diseases. Herein,we have reviewed the epidemiology,modes of transmission,predisposing factors,and novel treatment modalities of these viruses. We have proposed practices and interventions to decrease the risk of transmission of HCV and HBV in the affected countries,including strict adherence to standard precautions in the healthcare setting,rigorous education and training of patients and healthcare providers,universal screening of blood donors,use of safetyengineered devices,proper sterilization of medical equipment,hepatitis B vaccination,as well as effective direct-acting antiviral agents for the treatment of HCV.展开更多
Hepatitis B virus(HBV),a major cause of human liver disease worldwide,encodes three envelope proteins needed for the attachment and entry of the virus into susceptible host cells.A second virus,hepatitis delta virus,w...Hepatitis B virus(HBV),a major cause of human liver disease worldwide,encodes three envelope proteins needed for the attachment and entry of the virus into susceptible host cells.A second virus,hepatitis delta virus,which is known to enhance liver disease in HBV infected patients,diverts the same HBV envelope proteins to achieve its own assembly and infection.In the lab,lentiviral vectors based on human immunodeficiency virus type 1 can be assembled using the HBV envelope proteins,and will similarly infect susceptible cells.This article provides a partial review and some personal reflections of how these three viruses infect and of how recipient cells become susceptible,along with some consideration of questions that remain to be answered.展开更多
Objective To develop an effective and specific medicine targeting hepatitis B virus(HBV) pregenome. Based on the identified accessible target sites for hammerhead ribozyme in our previous researches, a recombinant hep...Objective To develop an effective and specific medicine targeting hepatitis B virus(HBV) pregenome. Based on the identified accessible target sites for hammerhead ribozyme in our previous researches, a recombinant hepatitis delta virus(HDV) ribozyme was chosen and used to demonstrate the effective cleavage in vitro and in vivo. Methods Three hammerhead ribozymes for potential target sites(S, X and C genes) and co-expression plasmid(pTr-dB, pTdδ-dB, pTrX-dB and pTrC-dB) as well as four HDV-ribozyme chimera constructs with HBV(pTdXX, pTdXC, pTdSX and pTdSC) were severally chosen to validate the inhibition of the replication and expression of HBV. The co-expression plasmids(pTdδ and pTr-Db) in physiological saline were hydrodynamically injected to mice by tail vein. Results Compared with the group injected with pTr-dB in Huh-7 cell, hepatitis B surface antigen(HBsAg) was reduced by 31% in the group injected with pTdδ-dB, by 54%, 26%, 72% and 97% in the group injected with recombinant-ribozymes pTdSX, pTdSC, pTdXC and pTdXX, respectively. The inhibiting effects of endogenous ribozymes RzX and RzC on the HBsAg expression were 66% and 57%, respectively. Compared with the positive control, the amount of HBsAg was decreased in mice injected with pTdXX through tail vein by 88% and 96% on the second day and the third day, respectively. HBsAg was undetectable on the 6th day and could not primitively be detected on the 9th day in the sera from all mice. HBV DNA was not detected in the sera of BALB/c mice injected with pTdXX-dB, pTrX-dB or replicating-defective plasmid pHBV, while HBV DNA replication in control group could be detected on the 6th day. While HBcAg could not be detected in liver tissues of mice injected with plasmid pTdXX-dB on the 3rd day. Conclusions Encoding regions of HBV S, C and X gene were the effective cleavage sites for hammerhead ribozyme in vitro and in vivo, which provides basis for further construction of therapeutic recombinant HDV and the development of targeting antiviral gene therapy.展开更多
文摘Chronic delta hepatitis is the most severe form of viral hepatitis affecting nearly 65 million people worldwide.Individuals with this devastating illness are at higher risk for developing cirrhosis and hepatocellular carcinoma.Delta virus is a defective RNA virus that requires hepatitis B surface antigen for propagation in humans.Infection can occur in the form of a co-infection with hepatitis B,which can be self-limiting,vs superinfection in a patient with established hepatitis B infection,which often leads to chronicity in majority of cases.Current noninvasive tools to assess for advanced liver disease have limited utility in delta hepatitis.Guidelines recommend treatment with pegylated interferon,but this is limited to patients with compensated disease and is efficacious in about 30%of those treated.Due to limited treatment options,novel agents are being investigated and include entry,assembly and export inhibitors of viral particles in addition to stimulators of the host immune response.Future clinical trials should take into consideration the interaction of hepatitis B and hepatitis D as suppression of one virus can lead to the activation of the other.Also,surrogate markers of treatment efficacy have been proposed.
文摘Hepatitis D virus(HDV) is the smallest single stranded RNA virus infecting humans. The hepatitis B surface antigen envelope protein protects the HDV nucleocapsidantigen and provides a means for the virus to enter and exit the hepatocyte. Hepatitis B and D viruses exploit the human sodium taurocholate co-transporting polypeptide(NTCP), a receptor, for their entry into hepatocytes. Prenylation of the large delta antigen is a critical determinant of HDV particle assembly. Treatment with pegylated interferon results in sustained virological response six months post-treatment in one fourth of the patients. Nucleos(t)ide analogs(NAs) have been widely tested in hepatitis delta, but they appear to be ineffective. Combination treatment of NAs with interferon also proved to be disappointing so there is a need for novel therapeutic options. The receptor function of NTCP is blocked by Myrcludex B, a synthetic N-acylated pre S1 lipopeptide that competes with infectious virions for receptor binding. There are already some approved drugs available, including irbesartan, ezetimibe, and ritonavir and cyclosporin A, with documented inhibitory effects on NTCP's metabolic function. These drugs may have a role in HDV treatment. Interference with hostmediated post-translational changes of proteins that are crucial to the HDV life cycle, such as prenylation may become an important tool to control HDV infection and prevent replication. Lonafarnib, a prenylation inhibitor significantly reduces virus levels in hepatitis delta patients. Antisense oligodeoxynucleotides which are complementary to genomic HDV ribozyme self-cleavage site and stem?Ⅰ?regions can inhibit genomic HDV ribozyme activity.
文摘Hepatitis D virus(HDV) is a defective RNA virus which requires the help of hepatitis B virus(HBV) virus for its replication and assembly of new virions. HDV genome contains only one actively transcribed open reading frame which encodes for two isoforms of hepatitis delta antigen. Post-translational modifications of small and large delta antigens(S-HDAg and L-HDAg) involving phosphorylation and isoprenylation respectively con- fer these antigens their specific properties. S-HDAg is required for the initiation of the viral genome replica- tion, whereas L-HDAg serves as a principal inhibitor of replication and is essential for the assembly of new virion particles. Immune mediation has usually been implicated in HDV-associated liver damage. The patho- genesis of HDV mainly involves interferon-α signaling inhibition, HDV-specific T-lymphocyte activation and cytokine responses, and tumor necrosis factor-alpha and nuclear factor kappa B signaling. Due to limited protein coding capacity, HDV makes use of host cel- lular proteins to accomplish their life cycle processes, including transcription, replication, post-transcriptional and translational modifications. This intimate host- pathogen interaction significantly alters cell proteome and is associated with an augmented expression of pro-inflammatory, growth and anti-apoptotic factorswhich explains severe necroinflammation and increased cell survival and an early progression to hepatocellular carcinoma in HDV patients. The understanding of the process of viral replication, HBV-HDV interactions, and etio-pathogenesis of the severe course of HDV infection is helpful in identifying the potential therapeutic targets in the virus life cycle for the prophylaxis and treatment of HDV infection and complications.
基金Supported by the Instituto de Salud Carlos Ⅲ,grants PI15/00856 and PI17/02233co-financed by the European Regional Development Fund(ERDF)
文摘Hepatitis delta virus(HDV) seems to strongly suppress hepatitis B virus(HBV)replication, although little is known about the mechanism of this interaction. Both these viruses show a dynamic distribution of mutants, resulting in viral quasispecies. Next-generation sequencing is a viable approach for analyzing the composition of these mutant spectra. As the regulatory hepatitis B X protein(HBx) is essential for HBV replication, determination of HBV X gene(HBX)quasispecies complexity in HBV/HDV infection compared to HBV monoinfection may provide information on the interactions between these two viruses.AIM To compare HBV quasispecies complexity in the HBX 5' region between chronic hepatitis delta(CHD) and chronic HBV mono-infected patients.METHODS Twenty-four untreated patients were included: 7/24(29.2%) with HBeAgnegative chronic HBV infection(CI, previously termed inactive carriers), 8/24(33.3%) with HBeAg-negative chronic hepatitis B(CHB) and 9/24(37.5%) with CHD. A serum sample from each patient was first tested for HBV DNA levels.The HBX 5' region [nucleotides(nt) 1255-1611] was then PCR-amplified for subsequent next-generation sequencing(MiSeq, Illumina, United States). HBV quasispecies complexity in the region analyzed was evaluated using incidencebased indices(number of haplotypes and number of mutations), abundancebased indices(Hill numbers of order 1 and 2), and functional indices(mutation frequency and nucleotide diversity). We also evaluated the pattern of nucleotide changes to investigate which of them could be the cause of the quasispecies complexity.RESULTS CHB patients showed higher median HBV-DNA levels [5.4 logIU/mL,interquartile range(IQR) 3.5-7.9] than CHD(3.4 logIU/mL, IQR 3-7.6)(P = n.s.)or CI(3.2 logIU/mL, IQR 2.3-3.5)(P < 0.01) patients. The incidence and abundance indices indicated that HBV quasispecies complexity was significantly greater in CI than CHB. A similar trend was observed in CHD patients, although only Hill numbers of order 2 showed statistically significant differences(CHB2.81, I
基金Supported by NIH to Dr.Gudima,Nos.R01CA166213,R21AI097647,and R21AI099696
文摘Hepatitis delta virus(HDV) is the etiologic agent of the most severe form of virus hepatitis in humans. Sharing some structural and functional properties with plant viroids, the HDV RNA contains a single open reading frame coding for the only virus protein, the Delta antigen. A number of unique features, including ribozyme activity, RNA editing, rolling-circle RNA replication, and redirection for a RNA template of host DNA-dependent RNA polymerase Ⅱ, make this small pathogen an excellent model to study virus-cell interactions and RNA biology. Treatment options for chronic hepatitis Delta are scarce and ineffective. The disease burden is perhaps largely underestimated making the search for new, specific drugs, targets, and treatment strategies an important public health challenge. In this review we address the main features of virus structure, replication, and interaction with the host. Virus pathogenicity and current treatment options are discussed in the light of recent developments.
文摘目的了解丁型肝炎病毒（hepatitis delta virus，HDV）感染标志物在乙型肝炎病毒（hepatitis B virus，HBV）感染者中的分布状况并分析其临床意义。方法收集HBV感染者的临床资料和血清样本，通过酶联免疫分析法检测其血清HBV感染五项指标、HDVAg和Anti—HDV，结合临床诊断和生化指标进行分析。结果收集HBV感染者样本462例，其中无症状携带者210例，慢性肝炎175例，急性乙肝35例，肝纤维化42例，检出HDV感染率为4．8％，男性显著高于女性，肝纤维化组的HDV感染率最高，为9．5％，其次为慢性肝炎的6．9％，45—60岁人群的HDV感染率为7．8％，显著高于其他年龄段。结论慢性乙肝和肝纤维化病例的HDV感染显著增高，提示HDV感染与肝病的严重程度相关，建议对肝病患者开展血清HDV感染标志物检查，鉴别是否存在HDV重叠感染。
文摘Egypt has one of the highest prevalence rates of hepatitis C virus(HCV) in the world,mostly with genotype 4 that is highly associated with severe fibrosis. As a consequence,hepatocellular carcinoma has become the leading cause of cancer in this country. Mauritania is a highly endemic area for hepatitis B virus(HBV). HBV and HCV could both be iatrogenically transmitted through infected blood products,infected needles,and medical equipment improperly sterilized. Adequate and efficient healthcare and public health measures with good surveillance programs,access for screening,prevention strategies,and successful treatment are needed to halt the spread of these diseases. Herein,we have reviewed the epidemiology,modes of transmission,predisposing factors,and novel treatment modalities of these viruses. We have proposed practices and interventions to decrease the risk of transmission of HCV and HBV in the affected countries,including strict adherence to standard precautions in the healthcare setting,rigorous education and training of patients and healthcare providers,universal screening of blood donors,use of safetyengineered devices,proper sterilization of medical equipment,hepatitis B vaccination,as well as effective direct-acting antiviral agents for the treatment of HCV.
文摘Hepatitis B virus(HBV),a major cause of human liver disease worldwide,encodes three envelope proteins needed for the attachment and entry of the virus into susceptible host cells.A second virus,hepatitis delta virus,which is known to enhance liver disease in HBV infected patients,diverts the same HBV envelope proteins to achieve its own assembly and infection.In the lab,lentiviral vectors based on human immunodeficiency virus type 1 can be assembled using the HBV envelope proteins,and will similarly infect susceptible cells.This article provides a partial review and some personal reflections of how these three viruses infect and of how recipient cells become susceptible,along with some consideration of questions that remain to be answered.
文摘Objective To develop an effective and specific medicine targeting hepatitis B virus(HBV) pregenome. Based on the identified accessible target sites for hammerhead ribozyme in our previous researches, a recombinant hepatitis delta virus(HDV) ribozyme was chosen and used to demonstrate the effective cleavage in vitro and in vivo. Methods Three hammerhead ribozymes for potential target sites(S, X and C genes) and co-expression plasmid(pTr-dB, pTdδ-dB, pTrX-dB and pTrC-dB) as well as four HDV-ribozyme chimera constructs with HBV(pTdXX, pTdXC, pTdSX and pTdSC) were severally chosen to validate the inhibition of the replication and expression of HBV. The co-expression plasmids(pTdδ and pTr-Db) in physiological saline were hydrodynamically injected to mice by tail vein. Results Compared with the group injected with pTr-dB in Huh-7 cell, hepatitis B surface antigen(HBsAg) was reduced by 31% in the group injected with pTdδ-dB, by 54%, 26%, 72% and 97% in the group injected with recombinant-ribozymes pTdSX, pTdSC, pTdXC and pTdXX, respectively. The inhibiting effects of endogenous ribozymes RzX and RzC on the HBsAg expression were 66% and 57%, respectively. Compared with the positive control, the amount of HBsAg was decreased in mice injected with pTdXX through tail vein by 88% and 96% on the second day and the third day, respectively. HBsAg was undetectable on the 6th day and could not primitively be detected on the 9th day in the sera from all mice. HBV DNA was not detected in the sera of BALB/c mice injected with pTdXX-dB, pTrX-dB or replicating-defective plasmid pHBV, while HBV DNA replication in control group could be detected on the 6th day. While HBcAg could not be detected in liver tissues of mice injected with plasmid pTdXX-dB on the 3rd day. Conclusions Encoding regions of HBV S, C and X gene were the effective cleavage sites for hammerhead ribozyme in vitro and in vivo, which provides basis for further construction of therapeutic recombinant HDV and the development of targeting antiviral gene therapy.
