Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The targeted introduction of therapeutic genes into malignant cells based on receptor mediated endocytosis of ligand-DNA conjugates recently was established as a transfection system and provides a promising strategy for cancer therapy. Antiidiotype antibodies could be of particular interest for this approach because their immunoglobulin receptor idiotypes represent highly specific tumor markers. Their safe and specific applicability in vivo, alone or as immunotoxins, has been proven in clinical trials for passive immunotherapy and vaccination strategies. For these reasons we have explored the utility of antiidiotype antibodies for gene delivery systems using the reporter genes beta-galactosidase and luciferase. Two monoclonal antibodies, SIC5 and 5D10, specific for B-lymphoma cell lines, which represent models for murine plasmacytoma (38C13) and human non-Hodgkin's lymphoma (SU-DHL-4) have been covalently linked to polylysine via the heterobifunctional cross-linker SPDP. Highly efficient uptake and internalization of the immunoconjugates have been shown by fluorescence microscopy and fluorescence-activated cell sorting (FACS) analysis. Successful transfections have been shown at the RNA and the reporter gene level (beta-galactosidase, luciferase) using different promoter/enhancer systems. Beta-galactosidase activity was detected by flow cytometry (FACS-gal) analysis for both cell lines, and SU-DHL-4 cells showed significant luciferase activity.
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PMID:Antibody-mediated gene delivery for B-cell lymphoma in vitro. 898 39

Lymphotoxin-beta is a newly recognized member of the tumor necrosis factor ligand family. Recent studies have suggested a role for this cytokine in delayed-type hypersensitivity responses. To determine whether lymphotoxin-beta contributes to the development of contact sensitivity, we utilized an inhibitor protein that can effectively block binding of lymphotoxin-beta to its receptor. An adenoviral vector was created that encodes for a lymphotoxin-beta inhibitor protein consisting of the extracellular domain of the lymphotoxin-beta receptor fused to IgG heavy chain. Intravenous injection of the recombinant virus into BALB/c mice yielded plasma levels of inhibitor protein > 500 micrograms that persisted for 1 week. Mice treated in this manner were compared with control animals injected with adenovirus encoding beta-galactosidase, with respect to their ability to mount contact sensitivity responses to epicutaneously applied dinitro-fluorobenzene. Mice transduced with the lymphotoxin-beta inhibitor prior to the induction of contact sensitivity showed significantly suppressed ear swelling responses. By contrast, mice treated with the lymphotoxin-beta inhibitor prior to the elicitation of contact sensitivity showed no change in ear swelling responses in comparison to controls. These findings indicate that lymphotoxin-beta plays an important role in the afferent phase of the contact sensitivity response.
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PMID:Adenovirus-mediated blockade of lymphotoxin-beta inhibits the induction of contact sensitivity in mice. 929 89

Tumor cells, such as lymphoma cells, are possible targets for gene therapy. In general, gene therapeutic approaches require efficient gene transfer to host cells and sufficient transgene expression. However, lymphoma cells previously have been demonstrated to be resistant to most of the currently available gene transfer methods. The aim of this study was to analyze various methods for transfection of lymphoma cells and to improve the efficiency of gene delivery. In accordance with previously published reports, lymphoma cells were demonstrated to be resistant to lipofection and electroporation. In contrast, we present an improved adenoviral protocol leading to highly efficient gene transfer to lymphoma cell lines derived from B cells as well as primary lymphoma cells being achieved with an adenoviral vector system encoding the beta-galactosidase protein. At a multiplicity of infection of 200, up to 100% of Daudi cells and Raji cells and 70% of OCI-Ly8-LAM53 cells could be transfected. Even at high adenoviral concentrations, no marked toxicity was observed, and the growth characteristics of the lymphoma cell lines were not impaired. The transfection rates in primary cells derived from six patients with non-Hodgkin's lymphoma were 30-65%, respectively. Transfection efficiency could be further increased by addition of cationic liposomes to adenoviral gene transfer. Furthermore, we examined the expression of the Coxsackie-adenoviral receptor (CAR) and the integrin receptors on the lymphoma cell surface. Flow cytometric analysis showed that 88% of Daudi cells, 69% of Raji cells, and 6% of OCI-Ly8-LAM53 cells expressed CAR on the cell surface. According to our data, adenoviral infection of lymphoma cells seems to be mediated by CAR. In contrast, integrin receptors are unlikely to play a major role, because lymphoma cells were negative for alphavbeta3-integrins and negative for alphavbeta5-integrins. In conclusion, this study demonstrates that B-lymphoma cell lines and primary lymphoma cells can be efficiently transfected using an adenoviral vector system. By adding cationic liposomes, the efficiency of adenoviral gene transfer to primary tumor cells could be further improved. This protocol may have an impact on the use of lymphoma cells in cancer gene therapy.
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PMID:Efficient gene transfer into lymphoma cells using adenoviral vectors combined with lipofection. 1097 75

Hec-6st is a highly specific high endothelial venule (HEV) gene that is crucial for regulating lymphocyte homing to lymph nodes (LN). The enzyme is also expressed in HEV-like vessels in tertiary lymphoid organs that form in chronic inflammation in autoimmunity, graft rejection, and microbial infection. Understanding the molecular nature of Hec-6st regulation is crucial for elucidating its function in development and disease. However, studies of HEV are limited because of the difficulties in isolating and maintaining the unique characteristics of these vessels in vitro. The novel pClasper yeast homologous recombination technique was used to isolate from a BAC clone a 60-kb DNA fragment that included the Hec-6st (Chst4) gene with flanking sequences. Transgenic mice were generated with the beta-galactosidase (LacZ) reporter gene inserted in-frame in the exon II of Hec-6st within the isolated BAC DNA fragment. LacZ was expressed specifically on HEV in LN, as indicated by its colocalization with peripheral node vascular addressin. LacZ was increased in nasal-associated lymphoid tissue during development and was reduced in LN and nasal-associated lymphoid tissue by LTbetaR-Ig (lymphotoxin-beta receptor human Ig fusion protein) treatment in a manner identical to the endogenous gene. The transgene was expressed at high levels in lymphoid accumulations with characteristics of tertiary lymphoid organs in the salivary glands of aged mice. Thus, the Hec-6s-LacZ construct faithfully reproduces Hec-6st tissue-specific expression and can be used in further studies to drive expression of reporter or effector genes, which could visualize or inhibit HEV in autoimmunity.
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PMID:Transgenic LacZ under control of Hec-6st regulatory sequences recapitulates endogenous gene expression on high endothelial venules. 1736 May 66