Chronic hepatitis B infection is caused by hepatitis B virus(HBV) and a total cure is yet to be achieved. The viral covalently closed circular DNA(ccc DNA) is the key to establish a persistent infection within hepatoc...Chronic hepatitis B infection is caused by hepatitis B virus(HBV) and a total cure is yet to be achieved. The viral covalently closed circular DNA(ccc DNA) is the key to establish a persistent infection within hepatocytes. Current antiviral strategies have no effect on the pre-existing ccc DNA reservoir. Therefore, the study of the molecular mechanism of ccc DNA formation is becoming a major focus of HBV research. This review summarizes the current advances in ccc DNA molecular biology and the latest studies on the elimination or inactivation of ccc DNA, including three major areas:(1) epigenetic regulation of ccc DNA by HBV X protein,(2) immune-mediated degradation,and(3) genome-editing nucleases. All these aspects provide clues on how to finally attain a cure for chronic hepatitis B infection.展开更多
Chronic hepatitis B virus infection continues to be a major health burden worldwide.It can cause various degrees of liver damage and is strongly associated with the development of liver cirrhosis and hepatocellular ca...Chronic hepatitis B virus infection continues to be a major health burden worldwide.It can cause various degrees of liver damage and is strongly associated with the development of liver cirrhosis and hepatocellular carcinoma.Covalently closed circular DNA in the nucleus of infected cells cannot be disabled by present therapies which may lead to HBV persistence and relapse.In this review,we summarized the current knowledge on hepatitis B virus covalently closed circular DNA and its potential role as a therapeutic target.展开更多
To develop a fluorescent quantitative PCR assay based on Taq-Man chemistry to detect the covalenfly closed circular DNA （eccDNA） of duck hepatitis B virus （DHBV）, a pair of primers was designed from both sides of ...To develop a fluorescent quantitative PCR assay based on Taq-Man chemistry to detect the covalenfly closed circular DNA （eccDNA） of duck hepatitis B virus （DHBV）, a pair of primers was designed from both sides of the nick in the minus strand of DHBV and a Taq-Man probes between the primers, modified with 6-Fam at 5＇ end and Tamra at its 3＇ end was designed to detect the PCR products during PCR cycles. The DHBV DNA fragment was cloned into vector PUCm-T, and the recombinant plasmid was purified and subsequently qualified as the HBV DNA standard. The experimental conditions and reagents used in PCR assay for amplification were sophisticatedly optimized in order to yield a perfect amplification efficacy and reduce the possibility to produce non-specific amplification. It was demonstrated that the detect limit of assay was 10^3 copies/ml, and a linear standard curve was obtained between 10^5 -10^9 copies/ml [ C1 =-2.8361 ln（x） ＋ 41.45, r =-0.9985]. The coefficient of variation was 0.2%-3.14% and 2.22%-4.43% for intra- and inter-assay respectively. After a dynamic survey on the contents of DHBV DNA in serum of ducks, it was found that its peak value appeared at the second week of birth in ducks. It is evident that this method of Taq-Man fluorescent quantitative PCR assay appears to be simple, sensitive and specific.展开更多
乙型肝炎是感染乙型肝炎病毒(hepatitis B virus,HBV)引起肝脏慢性炎症性改变为主要特征的一类传染病。长期慢性感染将导致肝纤维化、肝硬化、肝癌等终末期肝病的发生,严重危害人民群众的健康。慢性乙型肝炎病毒感染依然是全球公共卫生...乙型肝炎是感染乙型肝炎病毒(hepatitis B virus,HBV)引起肝脏慢性炎症性改变为主要特征的一类传染病。长期慢性感染将导致肝纤维化、肝硬化、肝癌等终末期肝病的发生,严重危害人民群众的健康。慢性乙型肝炎病毒感染依然是全球公共卫生健康问题之一。目前临床上使用的抗病毒治疗方案难以实现对乙型肝炎病毒的彻底清除,其根源在于被感染肝细胞核内持续存在具有稳定结构的共价闭合环状DNA(covalently closed circular DNA,cccDNA)。本文对乙型肝炎病毒共价闭合环状DNA清除的研究进展进行综述,旨在寻找清除cccDNA的途径及办法从而达到乙型肝炎病毒的彻底清除。展开更多
基金supported by the Key Project of Hubei Province Natural Science Foundation(2014CFA075)the National Natural Science Foundation of China(31400153)the Applied Basic Research Program(2015060101010033),Wuhan,China
文摘Chronic hepatitis B infection is caused by hepatitis B virus(HBV) and a total cure is yet to be achieved. The viral covalently closed circular DNA(ccc DNA) is the key to establish a persistent infection within hepatocytes. Current antiviral strategies have no effect on the pre-existing ccc DNA reservoir. Therefore, the study of the molecular mechanism of ccc DNA formation is becoming a major focus of HBV research. This review summarizes the current advances in ccc DNA molecular biology and the latest studies on the elimination or inactivation of ccc DNA, including three major areas:(1) epigenetic regulation of ccc DNA by HBV X protein,(2) immune-mediated degradation,and(3) genome-editing nucleases. All these aspects provide clues on how to finally attain a cure for chronic hepatitis B infection.
文摘Chronic hepatitis B virus infection continues to be a major health burden worldwide.It can cause various degrees of liver damage and is strongly associated with the development of liver cirrhosis and hepatocellular carcinoma.Covalently closed circular DNA in the nucleus of infected cells cannot be disabled by present therapies which may lead to HBV persistence and relapse.In this review,we summarized the current knowledge on hepatitis B virus covalently closed circular DNA and its potential role as a therapeutic target.
文摘To develop a fluorescent quantitative PCR assay based on Taq-Man chemistry to detect the covalenfly closed circular DNA （eccDNA） of duck hepatitis B virus （DHBV）, a pair of primers was designed from both sides of the nick in the minus strand of DHBV and a Taq-Man probes between the primers, modified with 6-Fam at 5＇ end and Tamra at its 3＇ end was designed to detect the PCR products during PCR cycles. The DHBV DNA fragment was cloned into vector PUCm-T, and the recombinant plasmid was purified and subsequently qualified as the HBV DNA standard. The experimental conditions and reagents used in PCR assay for amplification were sophisticatedly optimized in order to yield a perfect amplification efficacy and reduce the possibility to produce non-specific amplification. It was demonstrated that the detect limit of assay was 10^3 copies/ml, and a linear standard curve was obtained between 10^5 -10^9 copies/ml [ C1 =-2.8361 ln（x） ＋ 41.45, r =-0.9985]. The coefficient of variation was 0.2%-3.14% and 2.22%-4.43% for intra- and inter-assay respectively. After a dynamic survey on the contents of DHBV DNA in serum of ducks, it was found that its peak value appeared at the second week of birth in ducks. It is evident that this method of Taq-Man fluorescent quantitative PCR assay appears to be simple, sensitive and specific.
