Global epidemiology and burden of hepatitis C

Despite rapid progress in our knowledge of hepatitis C virology and pathogenesis, little is known about the current and future burden of this infection throughout the world. Prevalence and population-based studies have suggested that complications of the liver disease associated with chronic hepatitis C infection may potentially require substantial health care resources and generate very high costs for medical systems in the United States, Europe and worldwide. Careful understanding and assessment of hepatitis C health and economic burdens are likely to guide better programs for the management of infected individuals and the prevention of complications.     

Hepatitis C virus molecular clones: from cDNA to infectious virus particles in cell culture

There has been major progress in our understanding of hepatitis C virus (HCV) molecular virology in recent years. An essential prerequisite for this progress was the availability of functional molecular HCV clones, that serve as a starting point in order to establish cell culture systems. The first of these was the HCV replicon system, which used self-replicating subgenomic viral RNAs. However, these replicons only recapitulated the intracellular life cycle, and did not support production of infectious virus: this became possible with the identification of an HCV isolate that, for unknown reasons, replicates to very high levels in a human hepatoma cell line. Cells containing this genome release virus particles that are infectious in cell culture and in vivo. Without doubt, this system provides new possibilities for molecular studies of the HCV life cycle and the development of novel antiviral concepts.     

戊型肝炎病毒研究新进展

戊型肝炎病毒(hepatitis E virus,HEV)是引起全球多地区大规模流行和散发病例的急性病毒性肝炎的病原体,发展中国家尤为突出;我国是戊型肝炎(hepatitis E,HE)流行的高发区.HE是一种人畜共患病,猪是人HEV病毒的主要储库,因而HE已成为一个全球性的的公共卫生问题.对HEV的病毒学和基因组特征、临床表征、流行病学、主要抗原表位以及HEV诊断试剂和疫苗研制的进展进行了综述.     

Molecular biology and pathogenesis of hepatitis E virus

The hepatitis E virus (HEV) is a small RNA virus and the etiological agent for hepatitis E, a form of acute viral hepatitis. The virus has a feco-oral transmission cycle and is transmitted through environmental contamination, mainly through drinking water. Recent studies on the isolation of HEV-like viruses from animal species also suggest zoonotic transfer of the virus. The absence of small animal models of infection and efficient cell culture systems has precluded virological studies on the replication cycle and pathogenesis of HEV. A vaccine against HEV has undergone successful clinical testing and diagnostic tests are available. This review describes HEV epidemiology, clinical presentation, pathogenesis, molecular virology and the host response to HEV infection. The focus is on published literature in the past decade. Equal contribution     

RNA viruses: emerging vectors for vaccination and gene therapy

The application of modern molecular techniques has profoundly influenced our understanding of virus function. As a consequence, virus biology is being directly applied to medical research. It is a reflection of the current pace of virology that we are now beginning to think of our ancient foes as useful and beneficial tools.     

《病毒学》课程的教学改革思路与实践探索

分析了《病毒学》课程及病毒学学科的发展特点。在总结病毒学传统教学经验的基础上,结合该学科的快速发展趋势,对该课程在新的历史条件下的教材选择、教学内容的改革与建设、实验配套的硬件与软件建设、实验教学安排等方面进行了讨论和分析,并介绍了武汉大学在病毒学课程建设与教学改革中的一些具体做法和体会。     

Recent contributions of in vitro models to our understanding of hepatitis C virus life cycle

Hepatitis C virus is a human pathogen responsible for liver diseases including acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma. Its high prevalence, the absence of a prophylactic vaccine and the poor efficiency of current therapies are huge medical problems. Since the discovery of the hepatitis C virus, our knowledge of its biology has been largely punctuated by the development of original models of research. At the end of the 1980s, the chimpanzee model led to cloning of the viral genome and the definition of infectious molecular clones. In 1999, a breakthrough was achieved with the development of a robust in vitro replication model named 'replicon'. This system allowed intensive research into replication mechanisms and drug discovery. Later, in 2003, pseudotyped retroviruses harbouring surface proteins of hepatitis C virus were produced to specifically investigate the viral entry process. It was only in 2005 that infectious viruses were produced in vitro, enabling intensive investigations into the entire life cycle of the hepatitis C virus. This review describes the different in vitro models developed to study hepatitis C virus, their contribution to current knowledge of the virus biology and their future research applications.     

从动物模型看乙型病毒性肝炎致病机制的研究进展

乙型肝炎病毒(Hepatitis B virus,HBV)是通过血液和体液传播的嗜肝DNA病毒,尽管有有效的预防疫苗,乙型病毒性肝炎仍是我国乃至全球人类健康的重大威胁。HBV的易感宿主只局限于人以及黑猩猩等灵长类动物,HBV感染性疾病的研究遇到很大困难。多种小动物研究模型的建立,使我们对HBV感染致病机制的认识有了很大进步,包括:分子病毒学特征、在感染细胞中生命周期、机体的抗病毒免疫反应、肝脏病变的免疫病理机制等。但是,由于已有动物模型的种种限制,我们对HBV感染及乙型肝炎发生和发展的认识还远远不够,目前除了抗病毒治疗外,还没有有效地治疗慢性乙肝的方法。建立能够真实反映临床HBV感染、乙肝发生和进展过程的纯系小鼠模型,对于我们全面深入地理解HBV感染的侵入机制、宿主和病毒之间相互作用,以及发展预防和治疗HBV感染的新方法都具有非常重要的意义。     

Fragment molecular orbital calculations for biomolecules

Exploring biomolecule behavior, such as proteins and nucleic acids, using quantum mechanical theory can identify many life science phenomena from first principles. Fragment molecular orbital (FMO) calculations of whole single particles of biomolecules can determine the electronic state of the interior and surface of molecules and explore molecular recognition mechanisms based on intermolecular and intramolecular interactions. In this review, we summarized the current state of FMO calculations in drug discovery, virology, and structural biology, as well as recent developments from data science.     

单纯疱疹病毒基因组的限制性核酸内切酶分析

为了获得单纯疱疹病毒(HSV)基因组的限制性核酸内切酶(RE)分析资料和选择合适的RE去研究HSV感染,用11种常用的RE对HSV两个型别的实验室标准毒株的基因组分别作了分析。比较研究的结果表明,BamHI、HpaI和PstI等RE较适于HSV的研究和分型。本研究所采用的小量提取HSV DNA的方法具有快速、简便和实用的特点,值得在HSV感染的诊断、分型和HSV分子流行病学诸研究中推广使用。     

Members of the NF90/NFAR protein group are involved in the life cycle of a positive-strand RNA virus

A major issue of current virology concerns the characterization of cellular proteins that operate as functional components of the viral multiplication process. Here we describe a group of host factors designated as 'NFAR proteins' that are recruited by the replication machinery of bovine viral diarrhea virus, a close relative of the human pathogen hepatitis C virus. The NFAR proteins associate specifically with both the termini of the viral RNA genome involving regulatory elements in the 5' and 3' non-translated regions. Modification of the protein interaction sites in the 3' non-translated region yielded viral RNAs that were replication deficient. Viral replication was also inhibited by RNAi approaches that reduced the concentration of RNA helicase A, a member of the NFAR group, in the host cell's cytoplasm. Further experimental data suggest that NFAR proteins mediate a circular conformation of the viral genome that may be important for the coordination of translation and replication. Because NFAR proteins are presumed components of the antiviral response, we suspect that viral recruitment may also serve to weaken cellular defense mechanisms.     

Pathogenesis of hepatitis C virus

Hepatitis C virus (HCV) infects approximately 170 million people worldwide including 2 million in Japan and induces serious chronic hepatitis that results in the development of steatosis, cirrhosis and ultimately hepatocellular carcinoma. The current combination therapy using pegylated interferon alpha and a nucleotide analogue ribavirin achieved a sustained virological response in about half population of individuals infected with HCV genotypes la and lb. More than two-thirds of the HCV-positive population has been chronically infected with genotype 1 in Western countries and Japan. Therefore, more effective therapeutics and preventative measures are needed for the treatment of hepatitis C patients who are not responsive to the current chemotherapy. HCV core protein is well known to be the viral capsid protein as well as the pathogenic factor that induces steatosis and hepatocellular carcinoma in the transgenic mice. In this review, we summarize the current status of our knowledge regarding the molecular mechanism by which HCV core protein induces liver steatosis and hepatocellular carcinoma and discuss on a future perspective for the development of novel therapeutics for chronic hepatitis C.     

Harnessed viruses in the age of metagenomics and synthetic biology: an update on infectious clone assembly and biotechnologies of plant viruses

Recent metagenomic studies have provided an unprecedented wealth of data, which are revolutionizing our understanding of virus diversity. A redrawn landscape highlights viruses as active players in the phytobiome, and surveys have uncovered their positive roles in environmental stress tolerance of plants. Viral infectious clones are key tools for functional characterization of known and newly identified viruses. Knowledge of viruses and their components has been instrumental for the development of modern plant molecular biology and biotechnology. In this review, we provide extensive guidelines built on current synthetic biology advances that streamline infectious clone assembly, thus lessening a major technical constraint of plant virology. The focus is on generation of infectious clones in binary T‐DNA vectors, which are delivered efficiently to plants by Agrobacterium. We then summarize recent applications of plant viruses and explore emerging trends in microbiology, bacterial and human virology that, once translated to plant virology, could lead to the development of virus‐based gene therapies for ad hoc engineering of plant traits. The systematic characterization of plant virus roles in the phytobiome and next‐generation virus‐based tools will be indispensable landmarks in the synthetic biology roadmap to better crops.     

Current Concepts of Viral Hepatitis and A Peek into the Future

New information has prompted revision of the conceptual framework for considering the epidemiology and virology of viral hepatitis. The means are now at hand to identify infections due to either Hepatitis A or B, as well as to implicate other etiologic agents in hepatitis. Immunologic evidence of variation in the antigens associated with Hepatitis B, and possibly in Hepatitis A, may explain some well known epidemiologic phenomena and has important implications in immune serum globulin prophylaxis. The ambiguous relationship of antigenemia and viremia in Hepatitis B is explored in relation to the hepatitis hazard of blood products, to trials of immune serum globulin, and to the potential role of the carrier-health worker in hepatitis transmission. The emerging concept of non-parenteral transmission of Hepatitis B is reviewed and future developments in the production of hepatitis vaccines and in experimental viral hepatitis in non-human primates is briefly discussed.     

Restriction fragment length polymorphism analysis and direct sequencing for determination of HBV genotypes in a Turkish population

The aim of this study was to analyze the restriction fragment length polymorphism and direct sequencing results in genotyping of hepatitis B virus from a Turkish population in a clinical virology laboratory. Serum samples of 54 chronic hepatitis B patients attending the Ege University Hospital were studied. Sequences of partial S gene PCR products were analysed and RFLP was performed. Fifty-three isolates could be identified by direct sequencing as genotype D. One sample needed to be cloned and determined as genotype D. Forty-two isolates were genotyped as D with RFLP according to published determinative patterns. Twelve isolates had undefined patterns. Eight of them suggested a mixture of isolates with different patterns and cloning of these samples confirmed the presence of heterogeneous isolates. Four isolates with undefined pattern were determined as genotype D by direct sequencing. All the studied isolates were genotype D. The results of this studied population suggest that RFLP is suitable for HBV genotyping in a routine clinical virology laboratory setting. However sequence analysis and even cloning may be needed to clarify indeterminate results.     

Human enteric viruses in the water environment: a minireview.

Water virology started around half a century ago, with scientists attempting to detect poliovirus in water samples. Since that time, other enteric viruses responsible for gastroenteritis and hepatitis, among a great variety of virus strains, have replaced enteroviruses as the main target for detection in the water environment. Technical molecular developments, polymerase-chain reaction (PCR) amplification being the method of choice, enable the detection of fastidious health-significant viruses. However, shortcomings of molecular procedures include their potential incompatibility with concentration methods, indispensable to reduce the water sample volume to assay for viruses, the inability to discern between infectious and non infectious material. On the other hand, these procedures are restrained to sophisticated laboratories and detection of alternative indicator organisms has been proposed. Bacterial indicators fail to give a reliable clue of the virological quality of water. Selected bacteriophage groups appear as a better choice for their use as virus indicators.     

Assembly of hepatitis C virus particles

Infection with hepatitis C virus (HCV) is a major risk factor for chronic hepatitis, cirrhosis and hepatocellular carcinoma. Once robust cell culture systems for production of recombinant infectious HCV became available, evidence on molecular mechanisms underlying assembly and release of the virus particles began to accumulate. Recent studies have demonstrated that lipid droplets and viral nonstructural proteins play key roles in HCV morphogenesis. This review considers the current knowledge about maturation of HCV structural proteins and production of viral infectious particles.     

肿瘤病毒的发现历程及在肿瘤发生机制中的研究意义

1911年Peyton Rous发现禽肉瘤病毒,从而建立了肿瘤病毒学这一学科领域。20世纪30年代,Richard发现哺乳动物肿瘤病毒,60年代发现第一个人类肿瘤病毒--EB病毒,随后相继鉴定出乙型肝炎病毒(HBV)和乳头状瘤病毒(HPV)。肿瘤病毒的深入研究带动了癌基因概念的确立和抑癌基因功能的发现,促进癌症疫苗的研究,后者可以抑制病毒的传染性并降低肿瘤的发病率。20世纪80-90年代发现了人T细胞白血病Ⅰ型病毒(HTLV-1),丙型肝炎病毒(HVC)及卡波西肉瘤病毒(KSHV)。目前已知6种病毒(EBV、HBV、HPV、HTLV-1、HCV、KSHV)引起世界范围10%-15%的癌症,因此,病毒不仅是许多人类癌症的病原体,还可以作为揭示人类恶性肿瘤发病机制的研究工具。     

Localizing DNA and RNA within nuclei and chromosomes by fluorescence in situ hybridization.

The enormous potential of in situ hybridization derives from the unique ability of this approach to directly couple cytological and molecular information. In recent years, there has been a surge of success in powerful new applications, resulting from methodologic advances that bring the practical capabilities of this technology closer to its theoretical potential. A major advance has been improvements that enable, with a high degree of reproducibility and efficiency, precise visualization of single sequences within individual metaphase and interphase cells. This has implications for gene mapping, the analysis of nuclear organization, clinical cytogenetics, virology, and studies of gene expression. This article discusses the current state of the art of fluorescence in situ hybridization, with emphasis on applications to human genetics, but including brief discussions on studies of nuclear DNA and RNA organization, and on applications to clinical genetics and virology. Although a review of all of the literature in this field is not possible here, many of the major contributions are summarized along with recent work from our laboratory.