肝炎病毒与EB病毒重叠感染

为探讨肝炎病毒（ＨＶ）与ＥＢ病毒（ＥＢＶ）重叠感染的状况和后果,我们用免疫酶法对１５４例各型病毒性肝炎患者作了ＥＢＶＩｇＡ抗体检测。结果发现,急性肝炎、慢性轻度肝炎、慢性中度肝炎、肝炎肝硬化、慢性重型肝炎和原发性肝癌ＶＧＡ－ＩｇＡ抗体的阳性率分别为２４．０％、３０．０％、５３．３％、６３．３％、４０．０％和７２．７％,与健康人（５．３％）比较,有非常显著升高（Ｐ＜０．０１）;原发性肝癌又较急性肝炎和慢性轻度肝炎高,并有非常显著意义差异（Ｐ＜０．０１）。ＨＢＶ和ＨＡＶ＋ＨＢＶ感染者比较,前者又较后者低（Ｐ＜０．０１）。重叠感染者的临床表现均为“肝炎型”,未见咽炎、腺热、胃肠、肺炎、肾炎、神经等类型。重叠感染者的ＣＤ＋３及ＣＤ＋４Ｔ细胞下降,ＣＤ＋８Ｔ细胞及ＩｇＧ,ＩｇＭ升高,与健康人比较差异非常显著意义（Ｐ＜０．０１）。结果提示：ＨＶ感染,不仅因免疫失调易感ＥＢＶ,又可因重叠感染而进一步使免疫功能失调;对病毒性肝炎的处理应强调免疫调节治疗。     

Virus Replication in Enucleate Cells: Vesicular Stomatitis Virus and Influenza Virus

The requirement of the presence of a nucleus for the replication of vesicular stomatitis virus and influenza virus has been examined by following the growth and development of these viruses in enucleate BS-C-1 cells. Vesicular stomatitis virus replicates normally in enucleate cells with the rate of production of infectious virus, the amount of virus-specific protein synthesis, and the type of proteins produced being essentially the same in nucleate and enucleate cells. Influenza virus does not replicate in enucleate cells, no virus gene products can be detected, and there is no inhibition of cellular protein synthesis.     

Infectious Rous Sarcoma Virus and Reticuloendotheliosis Virus DNAs

An efficient and quantitative assay for infectious Rous sarcoma virus and reticuloendotheliosis virus DNAs is described. The specific infectivities of viral DNA corresponded to one infectious unit per 10(5) to 10(6) viral DNA molecules. Infection with viral DNA followed one-hit kinetics. The minimal size of infectious Rous sarcoma virus DNA was approximately 6 million daltons, whereas the minimal size of infectious reticuloendotheliosis virus DNA was larger, 10 to 20 million daltons.     

Nucleocapsid Protein Subunits of Simian Virus 5, Newcastle Disease Virus, and Sendai Virus

Helical nucleocapsids of each of the paramyxoviruses simian virus 5 (SV5), Newcastle disease virus (NDV), and Sendai virus have been isolated in two different forms. One form contains larger protein subunits and is obtained from mature virions or infected cells dispersed by ethylenediaminetetraacetic acid. The other form possesses smaller subunits and is obtained from infected cells dispersed by trypsin. The estimated molecular weights of the larger subunits in the three viruses are similar: SV5, 61,000; Sendai virus, 60,000; NDV, 56,000. The smaller nucleocapsid subunits are also very similar: SV5, 43,000; Sendai virus, 46,000; NDV, 47,000. The helical nucleocapsid composed of the smaller subunit appears to be less flexible and more stable than that formed by the larger subunit. There is suggestive evidence that conversion of the larger subunit to the smaller by proteolytic cleavage may occur intracellularly. The possibility that such a mechanism could be involved in the accumulation of nucleocapsid in cells persistently infected with paramyxoviruses is discussed.     

Hepatitis C Virus: Assembly and Release of Virus Particles

Hepatitis C virus is a blood-borne virus that typically establishes a chronic infection in the liver, which often results in cirrhosis and hepatocellular carcinoma. Progress in understanding the complete virus life cycle has been greatly enhanced by the recent availability of a tissue culture system that produces infectious virus progeny. Thus, it is now possible to gain insight into the roles played by viral components in assembly and egress and the cellular pathways that contribute to virion formation. This minireview describes the key determining viral and host factors that are needed to produce infectious virus.     

Efficiency of Cell-Free and Cell-Associated Virus in Mucosal Transmission of Human Immunodeficiency Virus Type 1 and Simian Immunodeficiency Virus

Effective strategies are needed to block mucosal transmission of human immunodeficiency virus type 1 (HIV-1). Here, we address a crucial question in HIV-1 pathogenesis: whether infected donor mononuclear cells or cell-free virus plays the more important role in initiating mucosal infection by HIV-1. This distinction is critical, as effective strategies for blocking cell-free and cell-associated virus transmission may be different. We describe a novel ex vivo model system that utilizes sealed human colonic mucosa explants and demonstrate in both the ex vivo model and in vivo using the rectal challenge model in rhesus monkeys that HIV-1-infected lymphocytes can transmit infection across the mucosa more efficiently than cell-free virus. These findings may have significant implications for our understanding of the pathogenesis of mucosal transmission of HIV-1 and for the development of strategies to prevent HIV-1 transmission.     

Continuous-Flow Ultracentrifugation of Canine Distemper Virus and Infectious Canine Hepatitis Virus

The use of a Spinco L-4 zonal centrifuge with the B-XVI continuous-flow rotor for the purification of canine distemper and infectious canine hepatitis viruses is described. Up to 68 liters of virus was processed at one time. Infectious canine hepatitis virus was found to band at 39% sucrose and canine distemper virus banded between 32 and 48% sucrose. The virus was concentrated 10-fold, and the purity of the virus, as measured by protein concentration, was increased by 99%.     

鸡马立克氏病毒和网状内皮增生病毒感染肉鸡时的相互作用

为了研究鸡马立克氏病病毒(MDV)和网状内皮增生病病毒(REV)共感染时的相互作用,分别在REV母源抗体阳性(REV-Ab+)和阴性(REV-Ab-)及经MDV疫苗CVI988株免疫和不免疫的商品代肉鸡,比较了二种病毒在病毒血症水平和特异抗体效价上的相互影响.结果表明,在未经CVI988株免疫鸡,REV病毒血症对MDV强毒接种后的病毒血症水平及抗体效价无明显影响,但REV病毒血症显著抑制了CVI988疫苗免疫为鸡提供的抵抗力和抗体效价,因而提高了强毒MDV感染后的病毒血症的程度.另一方面,MDV感染会显著减弱REV-Ab+鸡对REV感染的抵抗力,提高REV-Ab+鸡在感染REV后的病毒血症水平并抑制对它的抗体效价.分析表明,MDV和REV共感染主要通过抑制鸡体的免疫功能来影响另一种病毒的复制及其致病作用.     

糖基化与病毒

糖类作为一类重要的生物分子其功能多种多样。而病毒这类微生物的感染大多数是由糖链介导的。以HIV、SARS、HBV、流感病毒为实例,介绍了糖基化在病毒蛋白的折叠运输、病毒的感染中的作用。     

GBV-C与艾滋病毒的相互作用及其机制

GBV-C（GB Virus C)是20世纪90年代中期发现的一种单股正链RNA病毒,属黄病毒科Pegivirus属,全基因组长约9.4 kb,编码约2 900个氨基酸序列.早期认为,该病毒与肝炎有关,但随后的研究发现,该病毒对人类无致病作用.最近的研究表明,GBV-C与艾滋病毒（人类免疫缺陷病毒,human immunodeficiency virus,HIV）共感染情况下可抑制HIV的增殖、提高机体免疫、延缓HIV 患者疾病进程.进一步研究GBV-C与HIV的相互作用及其机制可能会为艾滋病（acquired immune deficiency syndrome,AIDS）治疗提供新思路. 本文就GBV-C与HIV-1相互作用的两种主要类型--间接和直接的作用以及其机制进行了综述.     

Proteins and Glycoproteins of Paramyxoviruses: a Comparison of Simian Virus 5, Newcastle Disease Virus, and Sendai Virus

The polypeptides of three paramyxoviruses (simian virus 5, Newcastle disease virus, and Sendai virus) were separated by polyacrylamide gel electrophoresis. Glycoproteins were identified by the use of radioactive glucosamine as a carbohydrate precursor. The protein patterns reveal similarities among the three viruses. Each virus contains at least five or six proteins, two of which are glycoproteins. Four of the proteins found in each virus share common features with corresponding proteins in the other two viruses, including similar molecular weights. These four proteins are the nucleocapsid protein (molecular weight 56,000 to 61,000), a larger glycoprotein (molecular weight 65,000 to 74,000), a smaller glycoprotein (molecular weight 53,000 to 56,000), and a major protein which is the smallest protein in each virion (molecular weight 38,000 to 41,000).     

Innovative Toolbox for the Quantification of Drosophila C Virus,Drosophila A Virus,and Nora Virus

Quantification of viral replication underlies investigations into host-virus interactions. In Drosophila melanogaster, persistent infections with Drosophila C virus, Drosophila A virus, and Nora virus are commonly observed in nature and in laboratory fly stocks. However, traditional endpoint dilution assays to quantify infectious titers are not compatible with persistently infecting isolates of these viruses that do not cause cytopathic effects in cell culture. Here we present a novel assay based on immunological detection of Drosophila C virus infection that allows quantification of infectious titers for a wider range of Drosophila C virus isolates. We also describe strand specific RT-qPCR assays for quantification of viral negative strand RNA produced during Drosophila C virus, Drosophila A virus, and Nora virus infection. Finally, we demonstrate the utility of these assays for quantification of viral replication during oral infections and persistent infections with each virus.     

Electrophoretic Distribution of the Proteins and Glycoproteins of Influenza Virus and Sendai Virus

The proteins of influenza (WSN) and Sendai virus have been separated by polyacrylamide gel electrophoresis into five components. In both cases, three of these components were shown to be glycoproteins containing fucose, galactose, and glucosamine. Two protein components of each virus were probably free from these sugar residues, including the structural unit of the viral ribonucleoprotein (molecular weight of about 60,000 daltons).     

Comparison of Membrane Protein Glycopeptides of Sindbis Virus and Vesicular Stomatitis Virus

A comparison has been made of the membrane glycoproteins and glycopeptides from two enveloped viruses, Sindbis virus and vesicular stomatitis virus (VSV). Glycopeptides isolated from Sindbis virus and VSV grown in the same host appear to differ principally in the number of sialic acid residues per glycopeptide; when sialic acid is removed by mild acid treatment, the glycopeptides of the two viral proteins are indistinguishable by exclusion chromatography. Preliminary evidence argues that the carbohydrate moiety covalently bound to different virus-specified membrane proteins may be specified principally by the host.     

应用免疫电镜技术快速检测菜豆黄花叶病毒、马铃薯M病毒和燕麦花叶病毒

应用免疫吸附电流技术(ISEM)可有效地检测腐汁液中的菜豆黄花叶病毒(BYMV)、马铃薯M病毒(PVM)和燕麦花叶病毒(OMV)。BYMV,PVM和OMV三种抗血清的适宜工作浓度和对铜网的适宜包被时间均为1000倍和1小时,对同源病毒的适宜捕获时间分别为4℃下2、2和8小时。PVM和OMV的病汁液检测灵敏度均为稀释4000倍,而BYMV病汁液稀释16000倍时还能检测到少量病毒料子。ISEM捕获法和修饰法的结果表明,这三种病毒之间无血清学交叉反应。