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

---

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

Ligand-mediated approaches to gene transfer offer an alternative to viral vectors for both in vivo and in vitro applications. Although a significant percentage of the plasmid-based DNA complex is lost to lysosomal degradation following receptor-mediated endocytosis, simultaneous infection with adenovirus has been shown to increase the level of transgene expression [Curiel, Agarwal, Wagner and Cotten (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 8850-8854; Wagner, Zatloukal, Cotten, Kirlappos, Mechtler, Curiel and Birnstiel (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 6099-6103]. In this study we describe an adenovirus-based ligand complex where the plasmid DNA, polycation-ligand conjugate and adenovirus are contained within a single particle structure. At the core of the transfection particle is a replication-defective recombinant adenovirus encoding a cDNA minigene for human placenta alkaline phosphatase that was chemically modified with poly(L-lysine) (Ad-pLys). Electron microscopy of an adenovirus-based ligand complex formed by successively adding plasmid DNA and an asialo-orosomucoid-poly(L-lysine) conjugate to Ad-pLys revealed structures that appeared as intact viral particles coated with a dense biomolecular layer. Adenovirus-based ligand complexes containing either a luciferase or beta-galactosidase reporter plasmid were shown to efficiently deliver the plasmid transgene to cells that express the hepatic asialoglycoprotein receptor. Furthermore, the poly(L-lysine) modification greatly reduced the infectivity potential of the virus without causing a concomitant loss of augmented gene transfer. As an alternative to infectious virions, incomplete products of viral assembly were also considered as a source for endosomalytic activity. However, these defective virions were unable to significantly enhance plasmid transgene delivery.
...
PMID:Biochemical and functional analysis of an adenovirus-based ligand complex for gene transfer. 816 59

Previous studies have established that gene transfer into myocardial cells in vivo is detectable after direct injection of plasmid DNA. Recently, adenovirus vectors have been shown to provide an efficient method for gene transfer into a wide range of tissues. Therefore, this study sought to assess the efficiency and stability of adenovirus-mediated gene transfer into myocardium and to compare this method with that using plasmid-based gene transfer techniques. Adult rats underwent myocardial injection via a subdiaphragmatic approach. Gene transfer efficiency was compared using direct injection of an adenovirus vector encoding for the marker gene beta-galactosidase (beta-gal), a control adenovirus vector encoding for the cystic fibrosis transmembrane conductance regulator gene, a plasmid encoding for beta-gal, or a control plasmid. Hearts infected with an adenovirus vector containing the beta-gal gene showed significantly increased beta-gal enzymatic activity compared with hearts injected with beta-gal plasmid. Histological examination revealed that cardiac myocytes were the target of adenovirus-mediated gene transfer. A time course of gene expression showed that beta-gal enzymatic activity peaked during the first week following injection. Adenovirus vectors provide an efficient but transient method for in vivo gene expression in myocardium.
...
PMID:Efficient gene transfer into myocardium by direct injection of adenovirus vectors. 822 91

A chimeric protein capable of binding and neutralizing tumor necrosis factor (TNF) and lymphotoxin was expressed in mice transduced with a replication-incompetent adenoviral vector into which a TNF inhibitor gene had been engineered. Within 3 days following the injection of 10(9) infectious particles, the TNF inhibitor concentration exceeded 1 mg/ml of plasma; this level of expression was maintained for at least 4 weeks, and detectable TNF inhibitory activity was measured 6 weeks after injection of the recombinant virus. Introduction of the artificial gene produced a phenotypic effect comparable to homozygous deletion of the 55-kDa TNF receptor, in that animals were rendered highly susceptible to infection by Listeria monocytogenes, whereas control animals receiving a replication-incompetent virus coding for beta-galactosidase were capable of resisting Listeria challenge. Adenovirus-mediated transfer of a gene encoding a TNF inhibitor offers a practical means of imposing effective, long-term blockade of TNF activity in vivo for investigational and therapeutic purposes.
...
PMID:Prolonged and effective blockade of tumor necrosis factor activity through adenovirus-mediated gene transfer. 827 68

A variety of pulmonary disorders, including cystic fibrosis, are potentially amenable to treatment in which a therapeutic gene is directly transferred to the bronchial epithelium. This is difficult to accomplish because the majority of airway epithelial cells replicate slowly and/or are terminally differentiated. Adenovirus vectors may circumvent this problem, since they do not require target cell proliferation to express exogenous genes. To evaluate the diversity of airway epithelial cell targets for in vivo adenovirus-directed gene transfer, a replication deficient recombinant adenovirus containing the Escherichia coli lacZ (beta-galactosidase [beta-gal]) gene (Ad.RSV beta gal) was used to infect lungs of cotton rats. In contrast to uninfected animals, intratracheal Ad.RSV beta gal administration resulted in beta-gal activity in lung lysate and cytochemical staining in all cell types forming the airway epithelium. The expression of the exogenous gene was dose-dependent, and the distribution of the beta-gal positive airway epithelial cells in Ad.RSV beta gal-infected animals was similar to the normal cell differential of the control animals. Thus, a replication deficient recombinant adenovirus can transfer an exogenous gene to all major categories of airway epithelial cells in vivo, suggesting that adenovirus vectors may be an efficient strategy for in vivo gene transfer in airway disorders such as cystic fibrosis.
...
PMID:Diversity of airway epithelial cell targets for in vivo recombinant adenovirus-mediated gene transfer. 842 21

This study introduces a model for intracoronary gene transfer in murine cardiac isografts using adenovirus vectors. This approach may offer an opportunity to modulate alloreactivity after cardiac transplantation. Donor hearts were infected via the coronary arteries with a volume of 10(9) plaque-forming units per milliliter of a recombinant adenovirus containing the beta-galactosidase-encoding gene (Ad.CMVLacZ). In a control group, 200 microliters of normal saline solution was infused. The grafts were stored in 4 degrees C cold saline solution for 15 minutes, then transplanted heterotopically into syngeneic hosts (B10.BR). The grafts were harvested at 3, 7, 15, or 30 days (n = 5 for each group) after transplantation, and beta-galactosidase activity was assessed by histochemical staining (X-gal). All grafts were functioning when harvested. X-gal staining pattern was nonuniform with positive staining appearing in epicardial, myocardial, and endocardial cells, as well as in the vessel walls. The cells permissive to infection consisted predominantly of myocardial cells. The mean total numbers of beta-gal-positive staining cells per slice were 68.7 +/- 27.3 in the 3-day group, 330.4 +/- 53.8 in the 7-day group, 151.3 +/- 48.0 in the 15-day group, and 39.9 +/- 10.8 in the 30-day group, thus peaking in the 7-day group (p < 0.05). Control isografts (n = 5), retrieved at day 30, revealed no staining activity. In conclusion, our model demonstrates that intracoronary gene transfer to the transplanted murine cardiac grafts is feasible at the time of harvest. Adenovirus-mediated gene transfer produces widespread gene expression which, though perhaps transient, does not adversely affect myocardial structure or function. This technology may allow modification of graft immunogenicity in the future through the production of therapeutic proteins sufficient to modulate local immune responses.
...
PMID:Cardiac gene transfer by intracoronary infusion of adenovirus vector-mediated reporter gene in the transplanted mouse heart. 855 72

Adenovirus-mediated gene transfer to muscle is a promising technology for gene therapy of Duchenne muscular dystrophy (DMD). However, currently available recombinant adenovirus vectors have several limitations, including a limited cloning capacity of approximately 8.5 kb, and the induction of a host immune response that leads to transient gene expression of 3-4 weeks in immunocompetent animals. Gene therapy for DMD could benefit from the development of adenoviral vectors with an increased cloning capacity to accommodate a full-length (approximately 14 kb) dystrophin cDNA. This increased capacity should also accommodate gene regulatory elements to achieve expression of transduced genes in a tissue-specific manner. Additional vector modifications that eliminate adenoviral genes, expression of which is associated with development of a host immune response, might greatly increase long-term expression of virally delivered genes in vivo. We have constructed encapsidated adenovirus minichromosomes theoretically capable of delivering up to 35 kb of non-viral exogenous DNA. These minichromosomes are derived from bacterial plasmids containing two fused inverted adenovirus origins of replication embedded in a circular genome, the adenovirus packaging signals, a beta-galactosidase reporter gene and a full-length dystrophin cDNA regulated by a muscle-specific enhancer/promoter. The encapsidated minichromosomes are propagated in vitro by trans-complementation with a replication-defective (E1 + E3 deleted) helper virus. We show that the minichromosomes can be propagated to high titer (> 10(8)/ml) and purified on CsCl gradients due to their buoyancy difference relative to helper virus. These vectors are able to transduce myogenic cell cultures and express dystrophin in myotubes. These results suggest that encapsidated adenovirus minichromosomes may be useful for gene transfer to muscle and other tissues.
...
PMID:Encapsidated adenovirus minichromosomes allow delivery and expression of a 14 kb dystrophin cDNA to muscle cells. 881 25

Genetic manipulation offers great potential for studying the molecular and cellular processes which control or regulate the complex developmental properties of neurons. Gene transfer into neurons, however, is notoriously difficult. In this study we have used a replication-defective adenovirus (Adv/RSV beta gal), expressing beta-galactosidase (beta-gal) as a reporter gene, to infect dissociated cultures of rat hippocampal neurons and hippocampal slice cultures. Because future studies will require either long-term (e.g., developmental) or short-term (e.g., electrophysiological) expression of recombinant genes in neuronal cultures, we have optimized infection conditions for each situation. The Adv/RSV beta gal construct infects neurons and glial cells equally well, with no apparent alterations in cellular morphology. In slice cultures, the same efficiency and temporal control of beta-gal expression following Adv/RSV beta gal infection was achieved. Focal application of the adenoviruses, by microinjection, permitted infection of discrete subregions within the hippocampal explants. Whole cell recordings of dissociated hippocampal neurons and field recordings from the explant cultures, infected with Adv/RSV beta gal at low multiplicities of infection, indicated no significant alteration in the electrophysiological profiles of neurons in these cultures. The results demonstrate the utility of adenoviruses as gene transfer vectors for primary cultures of neurons. Adenovirus-mediated gene transfer into slice cultures also provides an opportunity to study development or plasticity in an environment where the circuitry and cytoarchitecture of the tissue are preserved and the areas of genetic manipulation can be spatially isolated.
...
PMID:Adenovirus-mediated gene transfer into dissociated and explant cultures of rat hippocampal neurons. 882 Sep 64

Single injections of recombinant cytokines/chemokines into tissue have provided insights into their possible roles during the inflammatory response. Adenoviral technology may allow us to mimic the in vivo situation more closely, with protein generated in a continuous but transient fashion. Replication-deficient human type 5 adenovirus containing a rat macrophage inflammatory protein-2 (MIP-2) gene insertion and cytomegalovirus promoter was injected into the mouse brain to investigate the inflammatory response to continuous overproduction of MIP-2. Adenovirus with a LacZ gene insertion expressing beta-galactosidase was used as a control. At doses of 10(4) to 10(7) plaque-forming units, a minimal inflammatory response was detected to the LacZ virus, with leukocyte recruitment that was restricted to the injection site. A dose of 10(7) plaque-forming units of both the LacZ and the MIP-2 vector produced extensive transgene product expression that persisted for at least 7 days. Astrocytes, recognized by their morphology, were the predominant cell type expressing MIP-2 and beta-galactosidase. A dose of 10(7) plaque-forming units of MIP-2 vector caused dramatic polymorphonuclear leukocyte (PMN) recruitment to the brain parenchyma after 2 days. PMN recruitment was still observed after 4 and 7 days, but had become more localized to the injection site and was associated with numerous foam-like macrophages. At both 2 and 7 days the blood-brain barrier was breached in the region of leukocyte recruitment. Despite the extent of leukocyte recruitment there were no overt signs of neuronal degeneration or demyelination. Our findings demonstrate that continuous production of MIP-2 in the CNS results in persistent PMN recruitment to the brain parenchyma with no evidence of tachyphylaxis. The lack of PMN recruitment to the brain parenchyma following CNS injury may be a result of deficient production of PMN chemoattractants.
...
PMID:Recombinant human adenovirus with rat MIP-2 gene insertion causes prolonged PMN recruitment to the murine brain. 892 Dec 71

Gene transfer as a therapeutic modality for the treatment of myocardial ischemia and/or infarction has been proposed as a revolutionary approach to improve collateral circulation, enhance myocardial viability and amplify healing. Our study was undertaken to assess the feasibility, efficiency, anatomic distribution, timing and localization of adenovirus-mediated gene transfer into the vicinity of infarcted myocardium in the adult mammalian heart. We induced myocardial infarction by subjecting rats to 60 min of coronary artery occlusion followed by sustained reperfusion. Gene transfer into the infarction area was performed using direct injection of a replication-defective adenovirus vector encoding the bacterial reporter gene, beta-galactosidase. A total of 5.0 x 10(9) plaque-forming units of virus was delivered into the left ventricular myocardium either immediately (n = 7) or at 7 (n = 6), 22 (n = 5) or 30 days (n = 5) after reperfusion of rat hearts. Control rats received either 50 microliters of saline 13 days after myocardial infarction (n = 2) or were not subjected to infarction and received Adenovirus carrying the beta-galactosidase gene as described above (n = 4). All rats were killed at 7 days after cardiac injection. Hearts were harvested, frozen and sectioned and stained for beta-galactosidase activity and with hematoxylin and eosin. Sections were evaluated by light microscopy. Relative beta-galactosidase activity was measured by digital planimetry and expressed as the ratio of the maximal area of beta-galactosidase staining relative to the total area of the section examined (% +/- S.E.M.). beta-galactosidase gene expression was limited mainly to viable myocytes at the border of the myocardial infarction. The area of transgene expression in the non-infarcted hearts (28 +/- 7%) was significantly higher (P = 0.02) than at any time point studied in infarcted tissues (3.4 +/- 1.2%, 1.4 +/- 1.0%, 2.8 +/- 0.8% and 3.4 +/- 0.9% at reperfusion and at 7, 22 and 30 days after myocardial infarction, respectively). Hearts injected 7 days after infarction had significantly less transgene activity (P = 0.03) with three of five samples displaying no macroscopically visible beta-gal activity. Following viral injection, an inflammatory response consisting of mononuclear cell infiltration was much less intense seven days following injection in non-infarcted control rat hearts than at any of the time points examined for infarcted hearts. Gene transfer into infarcted myocardium, while feasible, was limited by low transfection efficiency when compared to non-infarcted normal myocardium. Transgene expression in the infarcted myocardium appears restricted to residual cardiomyocytes in the periphery. Nevertheless, the ability to introduce genes into these viable peripheral cells might be a useful therapeutic strategy for enhancing neovascularization, collateral flow and healing.
...
PMID:Adenovirus-mediated gene transfer into infarcted myocardium: feasibility, timing, and location of expression. 893 Aug 2

Adenovirus vectors have several features that make them attractive for potential use in gene therapy, including a broad tissue tropism and an ability to infect quiescent or postmitotic cells. In light of this, we examined whether recombinant adenovirus vectors could transfer genes into neoplastic cells of patients with chronic lymphocytic leukemia (CLL), a leukemia of "resting" B cells. Using high-titer recombinant adenovirus vectors, we found we could transfer genes encoding beta-galactosidase or murine CD80 (B7-1) into the CLL B cells of all patients tested (n = 10). The efficiency of gene transduction into CLL B cells was approximately 100 to 1,000-fold lower than into HeLa cells at any given multiplicity of infection (MOI). At a MOI of 500, 10% to 70% of the CLL B cells from different patients were made to express the transgene, as assessed by multiparameter flow cytometric analysis. Sustained levels of expression with little loss in the percentage of infected cells were maintained for up to 9 days, at which point the analysis was stopped. We found that CLL B cells have markedly lower expression levels of integrins that facilitate internalization of adenovirus particles into target cells, perhaps accounting, in part, for the reduced efficiency of adenovirus-mediated gene transfer compared with that in HeLa cells. Although HeLa cells express high levels of alpha(v)beta5, and detectable amounts of alpha(v)beta3, we find CLL cells from all patients tested express only low amounts of alpha(v)beta3, and no detectable alpha(v)beta5. Activation of CLL cells via CD40 cross-linking enhances expression of alpha(v)beta3, and induces expression of alpha(v)beta5. This phenotypic change is associated with a fivefold increase in the efficiency of adenovirus-mediated gene transfer into such activated CLL B cells. This study demonstrates that adenovirus vectors can transduce genes into CLL B cells and that the efficiency of gene transduction is enhanced by activation via CD40 cross-linking. This is the first demonstration that high proportions of CLL B cells can be made to express a selected transgene, suggesting that such gene transfer methods may become useful for the study of the pathogenesis and/or treatment of this disease.
...
PMID:Adenovirus vector infection of chronic lymphocytic leukemia B cells. 897 61


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---