Hepatitis B virus transgenic mouse model of chronic liver disease.

A model for hepatitis B virus-associated chronic liver disease has been made using cloned hepatitis B virus DNA as a transgene in a severe combined immunodeficient host. These mice consistently support virus gene expression and replication. After adoptive transfer of unprimed, syngeneic splenocytes, these mice cleared virus from liver and serum, and developed chronic liver disease. This model will permit identification of the host and virus contributions to chronic liver disease in the absence of tolerance.     

利用寡核苷酸微阵列技术对HBV、HCV、HIV、HAV、GBV-C/HGV和B19进行同时监测的初步研究

探讨研制能同时检测HBV、HCV、HIV、HAV、GBV-C/HGV和B19的微阵列监控芯片。根据病毒公开发表序列,序列比对,得出保守区域,设计病毒的特异性检测探针,同时设置阴性、阳性参照探针,制备监控微阵列。利用随机引物PCR方法标记样品中的病毒靶序列,标记产物与微阵列上的探针杂交,清洗、扫描后进行结果分析。通过对质粒或模式分子的检测以及经HBV、HCV、HIV临床标本的验证,发现该微阵列监控芯片具有良好的特异性。其对质粒的检测灵敏度可达102病毒拷贝数,对临床标本的检测灵敏度可达103病毒拷贝数。此外,该微阵列监控芯片可检测出病毒混合感染血清。为微阵列监控芯片应用于此六种血液病毒的检测打下一定的基础。     

Seroprevalence of the Hepatitis B,Hepatitis C,and Human Immunodeficiency Viruses and Treponema pallidum at the Beijing General Hospital from 2010 to 2014: A Cross-Sectional Study

BackgroundThe hepatitis B, hepatitis C, human immunodeficiency viruses and Treponema pallidum are important causes of infectious diseases concern to public health.MethodsBetween 2010 and 2014, we used an automated chemiluminescence microparticle immunoassay to detect the hepatitis B, hepatitis C, and human immunodeficiency viruses as well as Treponema pallidum (the rapid plasma regain test was used in 2010–2011). Positive human immunodeficiency virus tests were confirmed via western blotting.ResultsAmong 416,130 subjects, the seroprevalences for hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and Treponema pallidum were 5.72%, 1.23%, 0.196%, and 0.76%, respectively. Among 671 patients with positive human immunodeficiency virus results, 392 cases were confirmed via western blotting. Hepatitis B and human immunodeficiency virus infections were more frequent in men (7.78% and 0.26%, respectively) than in women (4.45% and 0.021%, respectively). The hepatitis B and C virus seroprevalences decreased from 6.21% and 1.58%, respectively, in 2010, to 5.37% and 0.988%, respectively, in 2014. The human immunodeficiency virus seroprevalence increased from 0.04% in 2010 to 0.17% in 2014, and was elevated in the Infectious Disease (2.65%), Emergency (1.71%), and Dermatology and Sexually Transmitted Diseases (1.12%) departments. The specificity of the human immunodeficiency virus screening was 71.4%. The false positive rates for the Treponema pallidum screening tests increased in patients who were 60–70 years old. The co-infection rates for the hepatitis C and human immunodeficiency viruses were 0.47% in hepatitis C virus-positive patients and 7.33% in human immunodeficiency virus-positive patients.ConclusionsDuring 2010–2014, hepatitis B virus and human immunodeficiency virus infections were more frequent among men at our institution. Although the seroprevalences of hepatitis B and C viruses decreased, the seroprevalence of human immunodeficiency virus infection increased (with higher seroprevalences in high-risk departments). Older patients were more likely to exhibit false positive findings for syphilis.     

乙型肝炎病毒相关性肾炎发病机制研究进展

乙型肝炎病毒相关性肾炎(hepatitis B virus-associated glomerulonephritis,HBV-GN)的发病机制尚未完全清楚,主要包括:①免疫复合物沉积介导的肾损伤是公认的主要发病机制。②乙型肝炎病毒(hepatitis B virus,HBV)直接感染肾脏,可原位表达其HBV抗原(HBAg)及其他产物介导肾损伤。③HBV感染后可导致宿主免疫功能缺陷,病毒不能被清除,体内持续存在的病毒可造成肾脏损伤迁延进展。④HBV基因变异可导致病毒致病力改变,并影响机体清除病毒。⑤遗传因素相关研究表明存在HBV-GN的易感基因。     

Serological relationship of woodchuck hepatitis virus to human hepatitis B virus.

Two antigenic systems of the woodchuck hepatitis virus have been identified. The relationship between viral antigens of the woodchuck hepatitis virus and the human hepatitis B virus was determined by using immunoprecipitation, hemagglutination, and immune electron microscopy techniques. Antigens found on the cores of the two viruses were cross-reactive. Lack of cross-reactivity between the surface antigens of the two viruses in immunodiffusion experiments suggested that the major antigenic determinants of the viral surfaces are different; however, results of passive hemagglutination tests indicated that there are common minor determinants. Nucleic acid homology, as measured by liquid hybridization, was found to be 3 to 5% of the viral genomes. The results of this study provide further evidence that woodchuck hepatitis virus is the second member of a new class of viruses represented by human hepatitis B virus. Since virus-infected woodchucks may acquire chronic hepatitis and hepatocellular carcinoma, these antigens and their respective antibodies will be useful markers for following the course of virus infection in investigations of the oncogenic potential of this class of viruses. The nucleocapsid antigen described may be a class-specific antigen of these viruses and, thus, may be useful in discovering new members of the group.     

Presence of replicating virus in recombinant hepadnavirus stocks results from recombination and can be eliminated by the use of a packaging cell line

Mutant hepatitis B viruses are useful tools to study the viral life cycle and viral pathogenesis. Furthermore, recombinant hepatitis B viruses are candidate vectors for liver-directed gene therapy. Because wild-type viruses present in recombinant or mutant virus stocks may falsify experimental results and are detrimental for a viral vector, we investigated whether and to what extent wild-type virus is present in recombinant virus stocks and where it originates from. We took advantage of the duck model of hepatitis B virus infection which allows very sensitive detection of replication-competent viruses by infection of primary duck hepatocytes or of ducklings in vivo. Recombinant hepatitis B virus stocks contained significant amounts of wild-type viruses, which were most probably generated by homologous recombination between plasmids containing homologous viral sequences. In addition, replication-competent viral genomes were reconstituted from plasmids which contained replication-deficient but redundant viral sequences. Using a stable cell line for packaging of deficient viral genomes, no wild-type virus was detected, neither by infection of primary hepatocytes nor in vivo.     

Virus assembly, allostery and antivirals

Assembly of virus capsids and surface proteins must be regulated to ensure that the resulting complex is an infectious virion. In this review, we examine assembly of virus capsids, focusing on hepatitis B virus and bacteriophage MS2, and formation of glycoproteins in the alphaviruses. These systems are structurally and biochemically well-characterized and are simplest-case paradigms of self-assembly. Published data suggest that capsid and glycoprotein assembly is subject to allosteric regulation, that is regulation at the level of conformational change. The hypothesis that allostery is a common theme in viruses suggests that deregulation of capsid and glycoprotein assembly by small molecule effectors will be an attractive antiviral strategy, as has been demonstrated with hepatitis B virus.     

Hepatitis Viruses and Human Hepatocellular Carcinoma

Two hepatotropic viruses, hepatitis B and C viruses, are known to cause hepatocellular carcinoma in humans. Hepatocarcinogenesis is a complex, stepwise process that evolves over several to many years and precisely how hepatitis viruses contribute to malignant transformation of hepatocytes is uncertain. Hepatitis B vrus is integrated into cellular DNA in the great majority of hepatitis B virus-related hepatocellular carcinomas, whereas replicative intermediates of hepatitis C virus do not insert into chromosomal DNA, making it likely that different pathogenetic mechanisms operate with the two viruses. Indeed, evidence is mounting that both direct and indirect carcinogenic mechanisms, and often the two together, are involved in virus-induced hepatocellular carcinoma. In addition, evidence is now available that hepatitis B and C viruses interact synergistically in the pathogenesis of hepatocellular carcinoma. Animal models, — other members of the Hepadnaviridae family that cause tumors in their respecitve animal hosts, and transgenic mice into which the sequences of hepatitis B virus DNA have been inserted — are proving useful in elucidating putative mechanisms of hepatitis B virus-related hepatocarcinogenesis. Whatever the genesis of hepatitis virus-induced hepatocellular carcinoma, it is clear that hepatitis viruses do not act alone but in conjunction with other environmental carcinogens and a number of host factors.     

Transient expression of hepatitis B virus surface antigen (HBsAg) gene in monkey cells by a SV40-based virus vector

Summary We have constructed a recombinant SV40-based vector carrying the S gene coding for the hepatitis B virus surface antigen (HBsAg). This vector replicates as an episome in monkey COS7 cells, producing high levels of hepatitis B virus surface antigen (HBsAg), which is liberated in the cell medium, probably as a membrane vesicule. The vector also carries the SV40-late genes and produces recombinant viruses. These viruses were used to infect fresh cell culture, with detection of HBsAg in the medium. Thus, this virus vector can efficiently transduce the gene for HBsAg.     

消化道传播病毒性肝炎研究进展

病毒性肝炎是由多种不同肝炎病毒引起的,以肝脏损害为主要表现,具有广泛流行性和严重传染性的一类疾病,严重危害人类健康,是我国目前重大的公共卫生问题之一。迄今鉴定出的具有明确致病性的肝炎病毒主要是甲型肝炎病毒(HAV)、乙型肝炎病毒(HBV)、丙型肝炎病毒(HCV)、丁型肝炎病毒(HDV)和戊型肝炎病毒(HEV),分别引起甲、乙、丙、丁、戊型肝炎。病毒性肝炎按传播途径的不同可以分为两类,一类是经肠道外传播的病毒性肝炎,包括乙、丙、丁型肝炎;另一类是经肠道(即消化道)传播的肝炎病毒,包括甲肝和戊肝,其发病有季节性,可呈暴发流行。本文旨在对经消化道传播的病毒型肝炎(甲肝、戊肝)的病原学、流行病学特征及其影响因素、控制和预防作一综述,以期对其流行和科学防控研究提供参考。     

Surface antigenic determinants of mammalian "hepadnaviruses" defined by group- and class-specific monoclonal antibodies

The hepatitis B-like viruses (human hepatitis B virus, woodchuck hepatitis virus, ground squirrel hepatitis virus, and duck hepatitis B virus) are hepatotropic DNA viruses which have been referred to collectively as "hepadnaviruses." Using a murine monoclonal antibody (101-2) to the surface antigen of woodchuck hepatitis virus, we have shown that the surface antigens of mammalian hepadnaviruses (HBsAg, WHsAg, and GSHsAg) are antigenically related via a common determinant (HV/101). Furthermore, analysis with other monoclonal antibodies to WHsAg revealed that WHsAg and GHsAg are antigenically distinct, although the antigens had more determinants in common with each other than with HBsAg. The hepadnavirus group-specific antibody (101-2) reacted with HBsAg subtypic variants in a group-specific rather than subtype-specific manner. In conjunction with observations with an HBsAg-specific, group-reactive monoclonal antibody (BX259), the present data suggest that there are at least two group-reactive epitopes of HBsAg: one which is virus specific (HBV/259) and one which is common to two other mammalian hepadnaviruses (HV/101).     

The epidemiological aspects of viral hepatitides in Estonia]

The etiological structure of viral hepatitides among the adult population of Tallinn and the occurrence of markers of hepatitis B and hepatitis C virus infections in medical workers, addict introducing drugs intravenously and hemodialysis patients were studied. Changes in the etiological structure of viral hepatitides were established: they took the form of a decrease in the level of hepatitis A morbidity and the considerable growth of the role of hepatitides B and C, as well as the newly detected circulation hepatitis D virus. About one-third in the structure of morbidity in viral hepatitides were hepatitis cases without markers of hepatitis A, B or C viruses (non-A, non-B, non-C). The highest rates of hepatitis B virus infection (78.9%) and hepatitis C virus infection (82.5%) were detected among drug addicts. Their level of HBsAg was 8.8%. In the group of medical workers, 25% of the examinees, i.e. every fourth person, had markers of hepatitis B virus, while antibodies to hepatitis C virus were detected in 5% of cases. Among hemodialysis patients these rates were 21.4% and 10.7% respectively.     

Small rodent models of hepatitis B and C virus replication and pathogenesis

The narrow host range of infection supporting the long-term propagation of hepatitis B and C viruses is a major limitation that has prevented a more thorough understanding of persistent infection and t...     

Physical, chemical and morphologic dimensions of human hepatitis A virus strain CR326 (38578).

CR326 human hepatitis A virus purified by isopycnic banding from infected marmoset sera was shown to consist of 27 nm spherical particles on electron microscopic examination. The particles were identified as hepatitis A virus by tests for infectivity and by specific neutralization of infectivity with convalescent human hepatitis A serum. Also, indentical 27 nm viruses in liver extracts gave specific reactions with hepatitis A antisera when tested by immune electron microscopy. The bouyant density of the virus in CsCl was 1.34 and it was heat (60 degrees), ether and acid stable but was destroyed by heat (100 degrees), formalin (1:4000) and ultraviolet irradiation. Electron microscopic studies of sections of infected marmoset liver showed intracytoplasmic virus particles, usually in vesicles. Presumptive findings for RNA, together with the intracytoplasmic location of the virus, indicated the virus to be of RNA-type. The attributes of the virus indicate it is closely related to the enterovirus family and not to hepatitis B virus.     

Identification and characterization of avihepadnaviruses isolated from exotic anseriformes maintained in captivity

Five new hepadnaviruses were cloned from exotic ducks and geese, including the Chiloe wigeon, mandarin duck, puna teal, Orinoco sheldgoose, and ashy-headed sheldgoose. Sequence comparisons revealed that all but the mandarin duck viruses were closely related to existing isolates of duck hepatitis B virus (DHBV), while mandarin duck virus clones were closely related to Ross goose hepatitis B virus. Nonetheless, the S protein, core protein, and functional domains of the Pol protein were highly conserved in all of the new isolates. The Chiloe wigeon and puna teal hepatitis B viruses, the two new isolates most closely related to DHBV, also lacked an AUG start codon at the beginning of their X open reading frame (ORF). But as previously reported for the heron, Ross goose, and stork hepatitis B viruses, an AUG codon was found near the beginning of the X ORF of the mandarin duck, Orinoco, and ashy-headed sheldgoose viruses. In all of the new isolates, the X ORF ended with a stop codon at the same position. All of the cloned viruses replicated when transfected into the LMH line of chicken hepatoma cells. Significant differences between the new isolates and between these and previously reported isolates were detected in the pre-S domain of the viral envelope protein, which is believed to determine viral host range. Despite this, all of the new isolates were infectious for primary cultures of Pekin duck hepatocytes, and infectivity in young Pekin ducks was demonstrated for all but the ashy-headed sheldgoose isolate.     

Virus of Pekin ducks with structural and biological relatedness to human hepatitis B virus.

A virus found in the sera of Pekin ducks appears to be a new member of the human hepatitis B-like family of viruses. This virus had a diameter of 40 nm and an appearance in the electron microscope similar to that of human hepatitis B virus. The DNA genome of the virus was circular and partially single stranded, and an endogenous DNA polymerase associated with the virus was capable of converting the genome to a double-stranded circle with a size of ca. 3,000 base pairs. An analysis for viral DNA in the organs of infected birds indicated preferential localization in the liver, implicating this organ as the site of virus replication. In all of these aspects, the virus bears a striking resemblance to human hepatitis B virus and appears to be a new member of this family, which also includes ground squirrel hepatitis virus and woodchuck hepatitis virus.     

Virus-associated human tumors: cervical carcinomas and papilloma viruses

The latest experimental data on the role of viruses in the origin of human tumors are discussed. This group of viruses consists of T-cell leukemia virus type 1 (HTLV 1), herpes viruses (HHV 8 and Epstein-Barr virus), hepatitis B virus, and human papilloma viruses. The most typical feature of this group of viruses is a very long latent period from the initial infection to the development of the disease that varies between 10 and 40 years. The mechanism of malignant cell conversion is specific for each viral type but is mainly associated with a disruption of functions of cellular genes participating in the control of cell division and proliferation. It can be a direct inactivation of tumor suppressor genes by their interaction with viral gene products (papilloma viruses), or a trans-activation of cellular genes modulating cell proliferation by viral gene products (hepatitis B virus and HTLV 1). Viruses play an initiative role and additional genetic changes in the genome of infected cells are necessary for complete expression of the oncogenic potential of the viral genes. Only these cells will give rise to a monoclonal cell population with uncontrolled proliferation. New approaches for the creation of vaccines against cancers associated with hepatitis B virus and papilloma viruses (hepatocellular carcinomas and cervical tumors, respectively) are in progress. These vaccines have been found to be effective in prevention of the disease in the experimental models and are now beginning to be used for human vaccination.     

Cyclophilin A and viral infections

Cyclophilin A (CyPA) is a peptidyl-prolyl cis/trans isomerase originally identified as the target of the immunosuppressive drug cyclosporine A. A number of reports have demonstrated that CyPA plays a critical role in the successful replication of viruses such as human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), etc. However, recent studies demonstrated that CyPA also possesses a repressive effect on the replication of some viruses like Influenza A virus and rotavirus. Moreover, CyPA could also regulate host IFN-I response to viral infections. Together, these evidences showed diverse roles of CyPA in viral infection.     

Inhibition of virus replication by RNA interference

RNA interference (RNAi) is a sequence-specific gene-silencing mechanism in eukaryotes, which is believed to function as a defence against viruses and transposons. Since its discovery, RNAi has been developed into a widely used technique for generating genetic knock-outs and for studying gene function by reverse genetics. Additionally, inhibition of virus replication by means of induced RNAi has now been reported for numerous viruses, including several important human pathogens such as human immunodeficiency virus type 1, hepatitis C virus, hepatitis B virus, dengue virus, poliovirus and influenza virus A. In this review, we will summarize the current data on RNAi-mediated inhibition of virus replication and discuss the possibilities for the development of RNAi-based antiviral therapeutics.