Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.2.1.23 (beta-galactosidase)
14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A herpes simplex virus (HSV) vector in which the mammalian promoter for neuron-specific enolase (NSE) controls expression of a marker gene was analyzed for its ability to drive expression of this foreign gene in culture and in vivo. In cultured cells, the vector appeared to give neuron-specific expression. Introduction of 10(6) pfu of the virus into the adult rat caudate nucleus by stereotactic injection was not toxic to the animals and yielded beta-galactosidase (beta-gal)-positive neurons for at least 30 days after viral inoculation. This recombinant herpes virus vector is the first described to use a mammalian promoter to yield extended expression of a foreign gene product in the adult mammalian central nervous system (CNS).
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PMID:Gene transfer into mammalian central nervous system using herpes virus vectors: extended expression of bacterial lacZ in neurons using the neuron-specific enolase promoter. 132 93

Marek's disease virus (MDV), a herpesvirus of avian origin, is being examined for suitability as a vector for expressing foreign genes. We observed that plasmids encoding the LacZ gene of E. coli under the control of either the herpes simplex virus alpha 4 immediate-early promoter or the cytomegalovirus major immediate-early promoter inhibited MDV plaque formation. Plaque numbers were decreased by one-third, and transient expression of the beta-galactosidase reporter gene was increased by up to 6-fold, when the plasmids were linearized. Sequences associated with the heterologous promoter were identified as being responsible for inhibiting MDV replication.
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PMID:Plasmid-associated effects on test gene expression and Marek's disease virus plaque formation during recombination trials. 133 74

Among the potential uses of defective herpes simplex virus (HSV-1) vectors are to study neuronal physiology, neuronal gene regulation, and to perform gene therapy of neuronal diseases. The prototype HSV-1 vector, pHSVlac, stably expresses Escherichia coli beta-galactosidase from the HSV-1 immediate early (IE) 4/5 promoter in cultured rat peripheral and CNS neurons, and in neurons in the adult rat brain. The LacZ gene and the IE 4/5 promoter in pHSVlac can be replaced with genes which affect neuronal physiology or cellular promoters, respectively. A system is required to characterize these HSV-1 vectors; cultured neurons, a mixture of different kinds of neurons and glia, cannot be used. In contrast, neural cell lines represent a homogenous population of neural cells available in virtually unlimited quantities. A system, using neural cell lines, to characterize HSV-1 vectors carrying other genes or promoters is now reported: First, 4 assays are described to detect HSV-1 vector DNA, RNA transcribed from the vector, and to quantitate beta-galactosidase expression. Second, 8 cell lines derived from rodents, primates, and humans were infected with pHSVlac virus and shown to express beta-galactosidase. The cell lines tested included adrenergic and cholinergic mouse neuroblastoma cells, rat pheochromocytoma cells, rodent pituicytes, and human neuroblastoma cells. Infection of these cell lines should prove useful for characterizing HSV-1 vectors with molecular and biochemical assays. Third, differentiated rat pheochromocytoma and mouse neuroblastoma cells, which resemble neurons, were infected with pHSVlac virus and shown to stably express beta-galactosidase. Infection of these cells should be useful for determining the effect of various HSV-1 vectors on neuronal physiology. Thus, HSV-1 vectors containing various genes or promoters can be characterized using the system described in this study.
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PMID:A system, using neural cell lines, to characterize HSV-1 vectors containing genes which affect neuronal physiology, or neuronal promoters. 164 53

Defective herpes simplex virus type 1 (HSV-1) vectors can deliver genes into both mitotic and postmitotic cells, including neurons and these vectors, therefore, have great potential use. pHSVlac, the prototype HSV-1 vector, expresses the E. coli Lac Z gene from the HSV-1 immediate early 4/5 promoter. pHSVlac can stably express beta-galactosidase in a range of mammalian cell lines and in neurons from throughout the nervous system, both in culture and in the adult rat brain. Thus, HSV-1 vectors may be useful for studying HSV-1 latency, neuronal physiology, and performing gene therapy for neurological conditions. A virus stock of pHSVlac consists of identical HSV-1 particles containing either pHSVlac DNA or the HSV-1 helper virus DNA. Thus, a cell can be infected with the pHSVlac virus, the helper virus, or both; consequently, it is important to determine if the helper virus influences the behavior of pHSVlac. The effect of the helper virus on expression of beta-galactosidase from pHSVlac was investigated: it was demonstrated first, that pHSVlac can be efficiently packaged into HSV-1 virus particles using each of five HSV-1 temperature sensitive (ts) mutants as helper virus. Second, pHSVlac grown with each of the five HSV-1 ts mutants expressed high levels of beta-galactosidase. Third, pHSVlac grown with HSV-1 strain 17 ts K as helper virus expresses the same amount of beta-galactosidase in the absence or presence of ts K. Thus, pHSVlac can efficiently express a gene independent of the HSV-1 helper virus.
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PMID:Influence of the helper virus on expression of beta-galactosidase from a defective HSV-1 vector, pHSVlac. 165 Jul 84

We present data which show that ribonucleotide (RR)-negative herpes simplex virus type-1 (HSV-1) is a useful vector for gene delivery into neuronal cells. For these studies we used hrR3, a genetically engineered HSV-1 mutant which has an in-frame insertion of the bacterial lacZ gene into the HSV gene that encodes the large subunit (ICP6) of RR. After infection of rat primary sympathetic neuronal cultures with hrR3, the ICP6::lacZ chimeric gene was expressed, as shown by blue staining of the cells upon exposure to X-Gal, a chromogenic beta-galactosidase substrate. When the infection was performed in the presence of acyclovir, hrR3 appeared to become "latent"; neither infectious virus nor beta-galactosidase activity was detectable in these neuronal cultures at 3 weeks after the acyclovir was removed. However, beta-galactosidase activity was inducible in the "latent" cultures by superinfection with ICP6 delta (a RR-negative deletion mutant) without resulting in the "reactivation" of hrR3 and without apparent cytopathic effects. In contrast, superinfection with ICP6 delta + 3.1, a virus derived by marker rescue of ICP6 delta, resulted in the expression of lacZ, the release of hrR3 into the culture medium, and cytopathic effects. The introduction of a foreign gene into neuronal cells by a RR-negative herpes simplex virus, and the subsequent induction of gene expression by another noncomplementing virus, may constitute a prototype gene delivery/recall system for neurons.
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PMID:A gene delivery/recall system for neurons which utilizes ribonucleotide reductase-negative herpes simplex viruses. 165 96

To investigate the cis-acting sequence elements that are involved in the regulation of herpes simplex virus type 1 late gene expression, linker-scanning mutations were constructed in the promoters of the glycoprotein C and glycoprotein H genes. Each promoter mutation was inserted upstream of the Escherichia coli lacZ gene in a recombinant virus, and the relative activities of beta-galactosidase expressed from individual recombinant viruses were compared. This analysis identified three sequence elements in each promoter: a TATA element, an element that overlapped the start of transcription, and an element downstream from the start of transcription. Primer extension analysis confirmed these results and showed that mutations in either the TATA element or the initiation sequence could eliminate normal transcription initiation. Analysis of expression from hybrid promoters revealed that the TATA and the initiation elements were interchangeable, at least when correctly aligned, and that the initiation element plays a pivotal role in determining the actual site of transcription initiation.
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PMID:Mutational analysis of two herpes simplex virus type 1 late promoters. 165 54

Several neurological diseases which affect the corpus striatum are candidates for gene therapy. We have developed a defective Herpes Simplex Virus (HSV-1) vector system to introduce genes into postmitotic cells, such as neurons. The prototype vector, pHSVlac, contains a transcription unit which places the E. coli Lac Z gene under the control of the HSV-1 immediate early (IE) 4/5 promoter, a constitutive promoter. We now demonstrate that a HSV-1 vector can deliver a gene into striatal neurons. Infection of cultured rat striatal neurons with pHSVlac virus resulted in stable expression of beta-galactosidase for at least two weeks, without cell death. The potential to replace the Lac Z gene with other genes of interest, such as the gene responsible for Huntington's Disease, once it is isolated, may lead to insights about the pathogenesis of this genetic neurodegenerative disease, and may provide a method for performing gene therapy on this disease. Similarly, introduction of the tyrosine hydroxylase gene, which encodes the rate-limiting enzyme in the conversion of tyrosine to dopamine, into striatal neurons might provide a novel gene therapy approach towards treating Parkinson's Disease.
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PMID:Infection of cultured striatal neurons with a defective HSV-1 vector: implications for gene therapy. 166 13

A genetically engineered herpes simplex virus type 1 (HSV-1, strain RH116) that expresses beta-galactosidase (beta-gal) was used as a marker to trace the route of interocular spread of HSV-1 after anterior chamber (AC) inoculation into BALB/c mice. Because RH116 is thymidine kinase deficient (TK-), the wild-type TK+ KOS strain of HSV-1 was used as a helper virus to complement RH116 during in vivo infection. After coinfection of BALB/c mice with RH116 and KOS in the AC of one eye, beta-gal expression by RH116 was detected in both the eyes and in the central nervous system (CNS). Our results suggest that after AC inoculation into BALB/c mice: (1) virus spreads from the injected eye to the CNS through parasympathetic fibers of the oculomotor nerve that supply the iris and ciliary body; (2) virus spread in the CNS is limited primarily to nuclei of the visual system and the suprachiasmatic area of the hypothalamus; and (3) virus is transmitted from the CNS to the retina of the contralateral eye by retrograde axonal transport through the optic nerve along the endocrine-optic pathway between the retina and the suprachiasmatic nucleus of the hypothalamus.
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PMID:Neural spread of herpes simplex virus after anterior chamber inoculation. 171 27

In-frame codon insertion and deletion mutants were constructed in a plasmid containing the sequence that encodes ICP0, a transcriptional activator of herpes simplex virus type 1 (HSV-1). The effect of these mutations was analyzed in a transient expression assay using the promoters for, the IE-0 gene (an immediate early (alpha) gene), the thymidine kinase gene (an early (beta) gene), and the glycoprotein C gene (a late (gamma) gene) fused to reporter cassettes that encoded either beta-galactosidase or chloramphenicol acetyl transferase. Assays were performed in the presence or absence of a plasmid encoding ICP4, the major regulatory protein of HSV-1. Our results demonstrate that ICP0-mediated transactivation varied depending on the position of the insertion in the gene. One region of this protein was consistently shown to be required for full activation of each promoter examined either in the presence or in the absence of ICP4. This region overlaps with a cysteine-rich region and coincides with a transactivator domain identified in another extensive mutational analysis of this sequence. Analysis of the deletion mutants generated in this study demonstrated that the carboxy-terminal regions were required for activation in certain circumstances and that this varied depending on the promoter being assayed and the cell type in which the analysis was performed.
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PMID:Mutational analysis of the sequence encoding ICP0 from herpes simplex virus type 1. 184 23

The genome of pseudorabies virus (PrV) encodes at least seven glycoproteins. The glycoprotein complex gII consists of three related polypeptides, two of them derived by proteolytic cleavage from a common precursor and linked via disulfide bonds. It is homologous to herpes simplex virus (HSV) gB and is therefore thought to be essential for PrV replication, as is gB for HSV replication. To isolate PrV mutants deficient in gII expression, we established cell lines that stably carry the PrV gII gene. Line N7, of Vero cell origin, contains the gII gene under its own promoter and expresses gII after transactivation by herpesviral functions after infection. MDBK-derived line MT3 contains the gII gene under control of the mouse metallothionein promoter. However, it has essentially lost inducibility and constitutively produces high amounts of correctly processed glycoprotein gII. We used a beta-galactosidase expression cassette inserted into a partially deleted cloned copy of the gII gene for cotransfection with PrV DNA. gII- PrV mutants were isolated from viral progeny by taking advantage of their blue-plaque phenotype when incubated under an agarose overlay containing a chromogenic substrate. Analysis of these mutants proved that gII is indeed essential for PrV replication, since the gII- mutants grew normally on gII-complementing cells but were unable to produce plaques on noncomplementing cells. Surprisingly the PrV gII- mutants were also able to grow on a cell line constitutively expressing the gB-homologous glycoprotein gI from bovine herpesvirus 1 (BHV-1) to the same extent as on cells expressing PrV gII. gII- PrV propagated on cells expressing BHV-1 gI became susceptible to neutralization by anti-BHV-1 gI monoclonal antibodies. We also found that BHV-1 gI is present in the envelope of purified gII- pseudorabies virions grown on cells expressing BHV-1 gI, as judged by radioimmunoprecipitation and immunoelectron microscopy. These results prove that BHV-1 gI is integrated into the PrV envelope and can functionally replace glycoprotein gII of PrV.
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PMID:Pseudorabies virus mutants lacking the essential glycoprotein gII can be complemented by glycoprotein gI of bovine herpesvirus 1. 184 88


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