Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lactobacillus strains possess properties that make them attractive candidates as vehicles for oral administration of therapeutics. In this report we describe the construction and analysis of recombinant Lactobacillus casei applicable in oral vaccination against an infectious disease (tetanus) and in oral tolerance induction for intervention in an autoimmune disease, multiple sclerosis. Recombinant L. casei which express surface-anchored tetanus toxin fragment C (TTFC) were generated. Quantitative analysis by flow cytometry demonstrated a high level of cell wall-bound expression of TTFC and immunogenicity was demonstrated by parenteral immunization with whole cell extracts of the recombinants. A series of expression vectors was constructed to secrete human myelin basic protein (hMBP) or hMBP as a fusion protein with beta-glucuronidase from Escherichia coli. These heterologous products produced by L. casei were detected in the growth medium and parenteral immunization with this medium evoked antibodies against hMBP, confirming that secretion indeed had occurred. Based on the different localization of the heterologous proteins, lactobacilli expressing surface-anchored TTFC are ideally suited for the induction of antibody responses, whereas lactobacilli that secrete myelin proteins can be used for the induction of peripheral T-cell tolerance. In conclusion, the specific technology described here allows the construction of a wide array of safe live recombinant lactobacilli which may prove to be useful in oral intervention strategies for the prevention of infectious diseases or treatment of autoimmune diseases.
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PMID:Instruments for oral disease-intervention strategies: recombinant Lactobacillus casei expressing tetanus toxin fragment C for vaccination or myelin proteins for oral tolerance induction in multiple sclerosis. 1036 44

The potential of lactic acid bacteria as live vehicles for the production and delivery of therapeutic molecules is being actively investigated today. For future applications it is essential to be able to establish dose-response curves for the targeted biological effect and thus to control the production of a heterologous biopeptide by a live lactobacillus. We therefore implemented in Lactobacillus plantarum NCIMB8826 the powerful nisin-controlled expression (NICE) system based on the autoregulatory properties of the bacteriocin nisin, which is produced by Lactococcus lactis. The original two-plasmid NICE system turned out to be poorly suited to L. plantarum. In order to obtain a stable and reproducible nisin dose-dependent synthesis of a reporter protein (beta-glucuronidase) or a model antigen (the C subunit of the tetanus toxin, TTFC), the lactococcal nisRK regulatory genes were integrated into the chromosome of L. plantarum NCIMB8826. Moreover, recombinant L. plantarum producing increasing amounts of TTFC was used to establish a dose-response curve after subcutaneous administration to mice. The induced serum immunoglobulin G response was correlated with the dose of antigen delivered by the live lactobacilli.
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PMID:Adaptation of the nisin-controlled expression system in Lactobacillus plantarum: a tool to study in vivo biological effects. 1101 Aug 94

The neurotropic atoxic fragment of tetanus toxin has been used as a carrier for transporting macromolecules into neurons but all studies to date have tested cytosolic proteins. In this study we investigated the effect of a genetic addition of the tetanus toxin C fragment sequence to a lysosomal enzyme which contains a signal sequence for insertion into the membrane-bound compartment and must be extensively modified in the endoplasmic reticulum (ER) and Golgi to attain functionality. In-frame fusion constructs between the atoxic C fragment and beta-glucuronidase were compared with the wild-type enzyme for: (i) enzymatic activity; (ii) heat stability; (iii) pH dependence; (iv) specific activity; (v) apparent molecular mass and (vi) receptor-mediated uptake by fibroblasts and neurons. The modified proteins had biochemical properties similar to wild-type enzyme but exhibited different enzyme secretion profiles. Addition of the secreted fusion enzyme to cultures of primary neurons showed significantly increased neuronal uptake of the modified protein compared with the wild-type, demonstrating the bifunctionality of the chimeric molecule.
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PMID:A genetic fusion construct between the tetanus toxin C fragment and the lysosomal acid hydrolase beta-glucuronidase expresses a bifunctional protein with enhanced secretion and neuronal uptake. 1593 52

We have developed a plant virus-mediated transgene activation (VMTA) system that utilizes a viral expression vector to present the inducer. The concept was tested using two well characterized components: (i) an artificial promoter based on the yeast GAL4 upstream activating sequence and the minimal TATA element of Cauliflower Mosaic Virus 35S RNA promoter, and (ii) a transcriptional activator (TA) consisting of a fusion between the GAL4 DNA binding domain and the Herpes simplex virus VP16 activation domain. The TA was expressed under the control of the subgenomic promoter of a Tobacco Mosaic Virus-based expression vector. The VMTA system was functional in transient Agroinfiltration assays with the reporter gene beta-glucuronidase, the intracellular domain of the diabetes associated autoimmune antigen, IA-2ic, and with the anti-tetanus antibody 9F12. Transgenic lines harboring the reporter gene were also examined. The VMTA system displayed tight transcriptional control in both transient assays and in transgenic Nicotiana benthamiana plants carrying the TA-inducible reporter.
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PMID:Inducible expression in plants by virus-mediated transgene activation. 1620 7