The Nucleocytoplasmic Transport of Viral Proteins

Molecules can enter the nucleus by passive diffusion or active transport mechanisms, depending on their size. Small molecules up to size of 50-60 kDa or less than 10 nm in diameter can diffuse passively through the nuclear pore complex (NPC), while most proteins are transported by energy driven transport mechanisms. Active transport of viral proteins is mediated by nuclear localization signals (NLS), which were first identified in Simian Virus 40 large T antigen and had subsequently been identified in a lar...     

Oxymatrine Inhibits Bocavirus MVC Replication,Reduces Viral Gene Expression and Decreases Apoptosis Induced by Viral Infection

Oxymatrine(OMT), as the main active component of Sophoraflavescens, exhibits a variety of pharmacological properties,including anti-oxidative, anti-inflammatory, anti-tumor, and anti-viral activities, and currently is extensively employed to treat viral hepatitis; however, its effects on parvovirus infection have yet to be reported. In the present study, we investigated the effects of OMT on cell viability, virus DNA replication, viral gene expression, cell cycle, and apoptosis in Walter Reed canine cells/3873 D infected with minute virus of canines(MVC). OMT, at concentrations below 4 mmol/L(no cellular toxicity), was found to inhibit MVC DNA replication and reduce viral gene expression at both mRNA and protein levels, which was associated with the inhibition of cell cycle S-phase arrest in early-stage of MVC infection.Furthermore, OMT significantly increased cell viability, decreased MVC-infected cell apoptosis, and reduced the expression of activated caspase 3. Our results suggest that OMT has potential application in combating parvovirus infection.     

Viral Detection: Past,Present, and Future

Viruses are essentially composed of a nucleic acid (segmented or not, DNA, or RNA) and a protein coat. Despite their simplicity, these small pathogens are responsible for significant economic and humanitarian losses that have had dramatic consequences in the course of human history. Since their discovery, scientists have developed different strategies to efficiently detect viruses, using all possible viral features. Viruses shape, proteins, and nucleic acid are used in viral detection. In this review, the development of these techniques, especially for plant and mammalian viruses, their strengths and weaknesses as well as the latest cutting‐edge technologies that may be playing important roles in the years to come are described.     

EBV编码miRNAs在病毒感染和肿瘤发生中的功能和意义

EB病毒(Epstein-Barr virus,EBV)是一种172 kb大小的线性双链DNA病毒,与鼻咽癌、淋巴瘤、胃癌等恶性肿瘤的发生密切相关. EBV编码的微小RNAs (miRNAs)可以调节病毒和宿主细胞基因的表达,并且在癌症发生发展中起着多种作用.本文综述了EBV编码的miRNAs (EBV-encoded miRNA,EBV miRNAs)在病毒感染和肿瘤发生、侵袭转移、抗凋亡、信号通路等方面的生物学功能,以及对于EBV相关肿瘤诊断标志物的潜在意义. EB病毒编码的miRNAs也可能成为进一步研究EBV相关肿瘤治疗的一个候选靶点.     

Native Immunogold Labeling of Cell Surface Proteins and Viral Glycoproteins for Cryo-Electron Microscopy and Cryo-Electron Tomography Applications

Numerous methods have been developed for immunogold labeling of thick, cryo-preserved biological specimens. However, most of the methods are permutations of chemical fixation and sample sectioning, which select and isolate the immunolabeled region of interest. We describe a method for combining immunogold labeling with cryo-electron microscopy (cryo-EM) and cryo-electron tomography (cryo-ET) of the surface proteins of intact mammalian cells or the surface glycoproteins of assembling and budding viruses in the context of virus-infected mammalian cells cultured on EM grids. In this method, the cells were maintained in culture media at physiologically relevant temperatures while sequentially incubated with the primary and secondary antibodies. Subsequently, the immunogold-labeled specimens were vitrified and observed under cryo-conditions in the transmission electron microscope. Cryo-EM and cryo-ET examination of the immunogold-labeled cells revealed the association of immunogold particles with the target antigens. Additionally, the cellular structure was unaltered by pre-immunolabeling chemical fixation and retained well-preserved plasma membranes, cytoskeletal elements, and macromolecular complexes. We think this technique will be of interest to cell biologists for cryo-EM and conventional studies of native cells and pathogen-infected cells.     

重组腺伴随病毒载体表达人白细胞介素12的研究

白细胞介素12(IL-12)具有广谱抗肿瘤、抗感染的作用,是由两个亚单位40kD(p40)和35kD(p35)通过二硫键构成的杂合体,有可能通过分别表达亚单位的方式来表达有功能活性的IL-12.该实验尝试利用重组腺伴随病毒(rAAV)载体进行人IL-12(hIL-12)双亚基共表达,将hIL-12的两个亚基分别克隆到AAV载体质粒pSNAV中,构建成pSNAV-IL12-p35和pSNAV-IL12-p40质粒,经转染、G418筛选后建立了rAAV载体细胞株.采用先前建立的rAAV的生产方法,获得了rAAV-IL12-p35和rAAV-IL12-p40,在体外将两种rAAV共同感染BHK-21细胞,48h后收集细胞培养上清进行免疫学和生物学活性检测.经ELISA检测,产生的hIL-12 p70的含量为10.185pg/ml;在体外促进IFN-γ分泌实验中,加入hIL-12的PBMC分泌的IFN-γ含量为37.2mg/ml.实验结果说明:采用两个AAV载体分别表达亚单位的方法可以表达具有功能活性的hIL-12,为IL-12的基因治疗提供了一条新的途径.     

Development of Improved Mumps Vaccine Candidates by Mutating Viral mRNA Cap Methyltransferase Sites in the Large Polymerase Protein

Virologica Sinica - Although a live attenuated vaccine is available for controlling mumps virus (MuV), mumps still outbreaks frequently worldwide. The attenuated MuV vaccine strain S79 is widely...     

江苏泰州地区HIV感染人群的血浆病毒群落研究

为探讨人类免疫缺陷病毒(Human immunodeficiency virus,HIV)感染人群血浆病毒群落组成,分析HIV感染人群血浆病毒群落的特点,研究病毒载量对HIV感染人群血浆病毒群落的影响,本研究通过Miseq高通量测序,对江苏泰州地区203份HIV感染人群的血浆样本进行了病毒宏基因组学分析。结果显示,高通量测序共得到243824条注释为病毒的序列,可注释到至少17个不同的病毒科(包括未分类病毒),包括12种哺乳动物类病毒(占99.87%),2种昆虫病毒(占0.05%),1种植物病毒(占不到0.01%),2种其他病毒(占0.02%)及未分类病毒;检出HIV病毒载量组的病毒群落中占据主导地位的是细小病毒科,其次是黄病毒科和指环病毒科,未检出病毒载量组中的主要病毒为黄病毒科,其次为指环病毒科和细小病毒科;系统进化分析显示,注释为细小病毒的序列与已知病毒的同源性较高,而注释为指环病毒和人佩吉病毒的序列中有部分序列与已知病毒同源性较高,另有部分序列与已知病毒的差异较大,疑似有新型病毒的存在;应用PCR扩增对部分病毒序列进行验证,将验证后的部分序列与原始序列进行比对,一致性达到近99%。     

SARS-CoV 基因组编码蛋白研究进展

严重急性呼吸综合征(severe acute respiratory syndrome,SARS)2002年底暴发于中国广东,后蔓延至全球的传染性疾病．其病原体为一种新型的未知冠状病毒,基因组长度约30 kb,预测具有14个开放读码框．至今为止,对 SARS 冠状病毒(SARS-COV)基因组编码蛋白质的研究已取得显著进展,其研究主要集中在复制酶 1a/1b、结构蛋白及“附属”蛋白(SARS-CoV 特异性蛋白)结构与功能的研究．以 SARS-CoV 的蛋白组成及功能研究为主要内容,系统介绍了 SARS-CoV 蛋白质研究进展．     

牛泡沫病毒长末端重复序列在大肠杆菌中的启动子功能

泡沫病毒具有复杂的基因组结构,包含典型反转录病毒共有的长末端重复序列(long terminal repeat,LTR)启动子,负责起始结构基因gag、pol、env的表达,并在env基因内部存在独有的内部启动子(internal promoter,IP)[13],用以起始下游反式作用因子Tas(在BFV中称Borf-1)的表达.有报道劳斯肉瘤病毒(rous sarcoma virus,RSV)和人免疫缺陷病毒(human immunodeficiency virus,HIV)LTR可在E.coli中起始基因表达[4,7].泡沫病毒至今未见报道.     

天津市致病毒性脑炎柯萨奇病毒B组5型全基因组序列分析

肠道病毒是我国病毒性脑炎(Viral encephalitis,VE)的主要病原体。本文研究对4株引起VE的天津柯萨奇病毒B组5型(Coxsackievirus B5,CV-B5)分离株进行Illumina MiniSeq高通量测序,并对其全基因组特征、进化及重组特点进行分析。结果提示,4株CV-B5天津分离株的全基因组核苷酸和氨基酸序列同源性分别为84.5%~100.0%和98.1%~100.0%,与国内流行株的全基因组核苷酸序列同源性为83.2%~96.5%,氨基酸序列同源性为96.4%~99.4%。基于全基因组的系统进化分析将CV-B5流行株分为A-D四个基因型,其中天津与国内流行株均属于C基因型。C基因型进一步分为3个进化分支,而天津分离株处在两个不同的分支上。基于基因组各区段序列的系统进化与SimPlot重组分析结果显示,天津分离株15-39N、15-41N与埃可病毒30型(Echovirus 30,E-30)原型株在P3区3B、3C、3D区域均检测到重组信号。本研究有助于了解CV-B5的全基因组特点和重组规律,为相关疾病的防控提供依据。     

MicroRNA-324-3p Plays A Protective Role Against Coxsackievirus B3-Induced Viral Myocarditis

Virologica Sinica - Viral myocarditis (VM) is an inflammatory disease of the myocardium associated with heart failure, which is caused by common viral infections. A majority of the infections are...     

A Molecular Basis for the Interplay between T Cells,Viral Mutants,and Human Leukocyte Antigen Micropolymorphism

Mutations within T cell epitopes represent a common mechanism of viral escape from the host protective immune response. The diverse T cell repertoire and the extensive human leukocyte antigen (HLA) polymorphism across populations is the evolutionary response to viral mutation. However, the molecular basis underpinning the interplay between HLA polymorphism, the T cell repertoire, and viral escape is unclear. Here we investigate the T cell response to a HLA-B*35:01- and HLA-B*35:08-restricted ⁴⁰⁷HPVGEADYFEY⁴¹⁷ epitope from Epstein-Barr virus and naturally occurring variants at positions 4 and 5 thereof. Each viral variant differently impacted on the epitope''s flexibility and conformation when bound to HLA-B*35:08 or HLA-B*35:01. We provide a molecular basis for understanding how the single residue polymorphism that discriminates between HLA-B*35:01/08 profoundly impacts on T cell receptor recognition. Surprisingly, one viral variant (P5-Glu to P5-Asp) effectively changed restriction preference from HLA-B*35:01 to HLA-B*35:08. Collectively, our study portrays the interplay between the T cell response, viral escape, and HLA polymorphism, whereby HLA polymorphism enables altered presentation of epitopes from different strains of Epstein-Barr virus.     

The DEAD-Box RNA Helicase DDX1 Interacts with the Viral Protein 3D and Inhibits Foot-and-Mouth Disease Virus Replication

Foot-and-mouth disease virus(FMDV) can infect domestic and wild cloven-hoofed animals. The non-structural protein 3 D plays an important role in FMDV replication and pathogenesis. However, the interaction partners of 3 D, and the effects of those interactions on FMDV replication, remain incompletely elucidated. In the present study, using the yeast two-hybrid system, we identified a porcine cell protein, DEAD-box RNA helicase 1(DDX1), which interacted with FMDV 3 D. The DDX1-3 D interaction was further confirmed by co-immunoprecipitation experiments and an indirect immunofluorescence assay(IFA) in porcine kidney 15(PK-15) cells. DDX1 was reported to either inhibit or facilitate viral replication and regulate host innate immune responses. However, the roles of DDX1 during FMDV infection remain unclear. Our results revealed that DDX1 inhibited FMDV replication in an ATPase/helicase activity-dependent manner. In addition, DDX1 stimulated IFN-b activation in FMDV-infected cells. Together, our results expand the body of knowledge regarding the role of DDX1 in FMDV infection.     

乙肝病毒载量与血清标志物及ALT相关性研究

探讨了乙型肝炎病毒核酸(HBV-DNA)水平与乙型肝炎免疫标志物(HBVM)和丙氨酸氨基转移酶(ALT)的关系。分别采用实时荧光定量聚合酶链反应(FQ-PCR),酶联免疫法和连续监测法检测了345例血清标本HBV-DNA含量,HBVM(HBsAg、HBsAb、HBeAg、HBeAb、抗HBcIgM)表达及ALT水平。HBsAg、HBeAg(和抗HBcIgM)阳性患者HBV DNA阳性率要明显高于HBsAg、HBeAb(和抗HBcIgM)阳性患者、仅HBsAg阳性患者及HBsAb、HBeAb阳性患者(P<0.01)。血清HBeAg阳性标本HBV-DNA阳性率为98.7%,明显高于HBeAg阴性标本的61.6%(P<0.01),并且血清HBeAg阳性标本HBV-DNA含量(log值,7.42±1.43)也明显高于HBeAg阴性标本(4.36±1.73)(P<0.01);在HBV-DNA含量小于107copy/mL的标本中,ALT与HBV-DNA含量呈正相关(P<0.01)。血清中HBV DNA含量与乙型肝炎免疫标志物以及肝细胞损伤三者之间存在密切的关系,在临床工作中应对血清HBVM、ALT和HBV-DNA含量联合检测,这样才能更准确地判断患者病情、预后及指导抗病毒药物的应用。