Early Inhibition of Acetylcholinesterase and Choline Acetyltransferase Activity in Herpes simplex Virus Type 1 Infection of PC12 Cells

Abstract: Early in the course of productive Herpes simplex virus type 1 (HSV-1) infection of PC12 cells, activities of both acetylcholinesterase (AChE) and choline acetyltransferase (CAT) fell. Studies using metabolic inhibitors and a temperature-sensitive mutant of the virus suggested that the decline in activities of both enzymes was associated with events occurring early in the replicative cycle related to expression of the immediate-early (α) group of viral polypeptides. HSV-1 gene products thus may alter specialized cell functions well before the production of viral progeny and initiation of cell lysis. The early clinical manifestations of nervous system viral infection may reflect focal metabolic disturbance rather than, or in addition to, simple cell death.     

A recombinant foot-and-mouth disease virus antigen inhibits DNA replication and triggers the SOS response in Escherichia coli

Abstract The 3D gene of foot-and-mouth disease virus encodes the viral RNA dependent RNA polymerase, also called virus infection associated (VIA) antigen, which is the most important serological marker of virus infection. This 3D gene from a serotype Cl virus has been cloned and overexpressed in Escherichia coli under the control of the strong lambda lytic promoters. The resulting 51 kDa recombinant protein has been shown to be immunoreactive with sera from infected animals. After induction of gene expression, an immediate and dramatic arrest of cell DNA synthesis occurs, similar to that produced by genotoxic doses of the drug mitomycin C. This effect does not occur during the production of either a truncated VIA antigen or other related and non-related viral proteins. The inhibition of DNA replication results in a subsequent induction of the host SOS DNA-repair response and in an increase of the mutation frequency in the surviving cells.     

Synthesis of the herpes simplex virus type 1 trans-activator Vmw65 in insect cells using a baculovirus vector

Vmw65, the Herpes Simplex Virus trans-activator of immediate-early genes, was expressed in insect cells using a recombinant baculovirus expression vector and partially purified. Insect cell-derived Vmw65 was shown to be indistinguishable from authentic Vmw65 present in purified HSV-1 virions based on electrophoretic mobility, immunoreactivity with a monoclonal antibody, and ability to interact with cellular factors to form a protein/DNA complex with oligonucleotides containing a TAATGARAT element.Abbreviations AcNPV Autographica californica nuclear polyhedrosis virus - HSV Herpes Simplex Virus - IE Immediate Early - moi multiplicity of infection - Sf9 Spodoptera frugiperda cells     

The cis-acting DNA sequences required in vivo for bacteriophage Mu helper-mediated transposition and packaging

The 37,000 bp double-stranded DNA genome of bacteriophage Mu behaves as a plaque-forming transposable element of Escherichia coli. We have defined the cis-acting DNA sequences required in vivo for transposition and packaging of the viral genome by monitoring the transposition and maturation of Mu DNA-containing pSC101 and pBR322 plasmids with an induced helper Mu prophage to provide the trans-acting functions. We found that nucleotides 1 to 54 of the Mu left end define an essential domain for transposition, and that sequences between nucleotides 126 and 203, and between 203 and 1,699, define two auxiliary domains that stimulate transposition in vivo. At the right extremity, the essential sequences for transposition require not more than the first 62 base pairs (bp), although the presence of sequences between 63 and 117 bp from the right end increases the transposition frequency about 15-fold in our system. Finally, we have delineated the pac recognition site for DNA maturation to nucleotides 32 to 54 of the Mu left end which reside inside of the first transposase binding site (L1) located between nucleotides 1–30. Thus, the transposase binding site and packaging domains of bacteriophage Mu DNA can be separated into two well-defined regions which do not appear to overlap.Abbreviations attL attachment site left - attR attachment site right - bp base pairs - Kb kilobase pair - nt nucleotide - Pu Purine - Py pyrimidine - Tn transposable element State University of New York, Downstate Medical Center, Brooklyn, NY 11204 USA     

Agroinfection and nucleotide sequence of cloned wheat dwarf virus DNA

Cloned DNA of the geminivirus wheat dwarf virus (WDV) was successfully used to infect seedling wheat plants. The clone was derived from circular double-stranded viral DNA isolated from naturally infected tissue. The initiation of infection was mediated by Agrobacterium tumefaciens using cloned dimeric WDV genomes in a binary Agrobacterium vector. The WDV DNA which comprised the infectious clone was sequenced and is compared with the published sequence of a Swedish isolate of the same virus. The results confirm that the single WDV genome component of 2.75 kb carries all the information necessary for production of viral symptoms, virus particles and viral double- and single-stranded DNA forms.     

不同动物制备的抗血清对病毒抗原免疫反应的差异

血清学技术是病毒诊断、鉴定、分类及亲缘关系分析的重要手段。一般常用以制备抗病毒血清的动物是家兔,但也有采用其它动物的,如蛙、羊、豚鼠、鸡及小鼠等。本文比较了Balb/c小鼠、昆明种小鼠和新西兰大白兔对长叶车前花叶病毒上海分离株(RMVsh)和烟草花叶病毒普通株(TMVc)的免疫反应特征。     

在大肠杆菌中人腺病毒5型及昆虫核多角体病毒晚期启动子表达CAT基因

本文证明,含有人5型腺病毒及苜蓿丫纹夜蛾核型多角体病毒(AutograPha californica Nuclear Polyhedrosis Virus, AcNPV)启动子的DNA片段,可在大肠杆菌中起始氯霉素乙酰基转移酶(Chloramphenicol Acetyltransferase,CAT)基因的转录和表达,使转化宿主菌表现为氯霉素抗性型。这说明,除痘苗病毒启动子外,其它人类病毒及昆虫病毒的启动子也能有效地在大肠杆菌中工作。     

纸坊病病毒病因的研究

1985年4～10月与1986年6～8月,在贵州省沿河县的纸坊村和崔家坨村先后发生了病因不明的传染病。纸坊村约有1/5的村民发病,病死率为12％,崔家坨村有1/10的村民发病,病死率高达30％。发病波及各年龄组,以青壮年为多,有家庭集聚现象。 本病起病急,轻症者只有头晕、乏力、肌痛、多汗、心悸伴以低热,有的初期有短暂的腹泻。重症者有高热(40℃以上)、大汗、心悸、游走性肌肉痉挛伴有明显疼痛和触痛,以腰骶部及四肢肌肉为好发部位。病人烦燥不安,2～5天内死亡。经实验室检查,排除了食物中毒、农药中毒、钩端螺旋体病和弓形体感染。从病人和接触者的粪便中分离到9株病毒,性状一致,为RNA型25nm的球形颗粒,耐酸,耐乙醚,能凝集人“O”型血球。经血清学鉴定为ECHO3型病毒。16份病人双份血清的检测结果表明,恢复期血清对该病毒中和抗体有4倍以上升高者共8例(纸坊村和崔家坨各4例)。病人单份血清也都有较高的抗体。有理由认为两年中先后在两个村庄发生的传染病与ECHO3型病毒有密切关系。查阅文献,尚未见有关ECHO3型病毒引起以肌痛、游走性肌痉挛为特征的疾病的报道。     

用核酸斑点杂交法比较油桐尺蠖核型多角体病毒与某些昆虫杆状病毒的同源性

有关核型多角体病毒基因同源性的研究报道不多,结果也不甚一致。目前,国内外普遍用SDS-PAGE法分析昆虫杆状病毒结构多肽,以限制性内切酶谱法测定基因组大小,借此区分来自不同宿主的病毒株,和基因组密切相关