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)

Endo-beta-galactosidase treatment of glycopeptides derived from the trypsinate and membranes of PC12 pheochromocytoma cells and cultured sympathetic neurons demonstrated the presence of poly(N-acetyllactosaminyl) units on tri- and tetraantennary oligosaccharides, some of which have a core fucose residue and a 2,6-substituted alpha-linked mannose residue. Nerve growth factor induced differentiation of the PC12 cells led to a small but significant decrease in the proportion of these oligosaccharides. Poly(N-acetyllactosaminyl) oligosaccharides were also identified in a major 230 000-Da cell-surface glycoprotein (the nerve growth factor inducible large external, or NILE, glycoprotein) of PC12 cells and appear to account for much or all of the difference in size between this glycoprotein as compared to the immunochemically cross-reactive 205 000-Da species present in postnatal brain. Glycoproteins containing poly(N-acetyllactosaminyl) oligosaccharides were selectively labeled by treatment of PC12 cells with endo-beta-galactosidase to expose N-acetylglucosamine residues, followed by incubation with galactosyltransferase and UDP-[14C]galactose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography revealed the presence of a number of distinct PC12 cell glycoproteins that contain these oligosaccharides and have apparent molecular weights in the range of 25 000-250 000. Treatment of PC12 cells with nerve growth factor (NGF) altered the relative labeling of several of the glycoprotein bands, with a time course similar to the effects of NGF on neurite outgrowth.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Poly(N-acetyllactosaminyl) oligosaccharides in glycoproteins of PC12 pheochromocytoma cells and sympathetic neurons. 375 58

Gene therapy approaches for the treatment of malignant tumors will require high-level expression of therapeutic genes in tumors compared with normal tissues. This may be achieved either by targeted gene delivery to tumor cells or by the use of tumor-specific promoters. Here, we describe the use of a novel conjugate consisting of a tumor-reactive monoclonal antibody (mAb), designated AF-20, coupled to a DNA-binding cationic amphiphile, cholesteryl-spermine, for gene delivery to hepatocellular carcinoma (HCC) cells. The high-affinity mAb, AF-20, recognizes a rapidly internalized 180-kd cell-surface glycoprotein that is abundantly expressed on HCC and other human tumors. The AF-20 mAb and an isotype-matched control antibody (C7-57) were covalently coupled to cholesteryl-spermine. Binding and internalization of AF-20-cholesteryl-spermine was confirmed by fluorescence microscopy using fluorescein isothiocyanate (FITC)-labeled anti-mouse IgG antibody. Following transfection of FITC-labeled oligonucleotides and ethidium monoazide-labeled plasmid DNA, cellular uptake and intracellular localization of nucleic acids were examined by laser scanning confocal microscopy. Transfection of luciferase or beta-galactosidase reporter genes complexed to AF-20-cholesteryl-spermine resulted in high levels of gene expression in AF-20 antigen-positive tumor cells. Very low levels of gene expression were observed using the control compound (C7-57-cholesteryl-spermine), which does not recognize the AF-20 tumor antigen or when AF-20 antigen-negative NIH 3T3 cells were transfected with AF-20-cholesteryl-spermine. Thus, covalent coupling of the AF-20 mAb to cholesteryl-spermine generated a highly specific and efficient nonviral vector system for targeted gene delivery to AF-20 antigen-positive HCC cells.
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PMID:Targeted gene transfer to hepatocellular carcinoma cells in vitro using a novel monoclonal antibody-based gene delivery system. 986 54

The therapeutic use of dendritic cells (DC) in antigen-specific anti-tumor vaccines, requires sufficient numbers of functional DC, the preparation of which should comply with the code of Good Manufacturing Practice. In addition, the expression of tumor specific antigen should be possible in these DC. As a preclinical step, the method reported here was developed in healthy volunteers. Monocytes (Mo) were isolated by leukapheresis from 12 donors, purified by elutriation and then cultured for 6 days in sealed bags in AIM-V serum free medium with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-13 (IL-13). Between 6x10(8) and 1x10(9) immature DC (iDC) could be differentiated from one leukapheresis. Cells displayed a characteristic iDC phenotype (CD1a(+), CD14(-), CD80(+), CD86(+), HLA DR(+), CD83(-)), and had potent allogeneic and antigen dependent autologous T cell-stimulatory capacity. Moreover, iDC could be further differentiated into mature DC by CD40 ligation as assessed by CD83 expression and the upregulation of HLA-DR and costimulatory molecules. After infection with a recombinant adenovirus encoding for beta-galactosidase (betaGal), 50% to 80% of iDC expressed betaGal without toxicity. Adenovirus infection increased the expression of both costimulatory molecules and CD83, and also increased allogeneic stimulatory capacity. Thus, the method developed here allows us to use large numbers of functional iDC as will be required for therapeutic uses in man. These DC can express a transgenic protein.
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PMID:Adenoviral transduction of human 'clinical grade' immature dendritic cells enhances costimulatory molecule expression and T-cell stimulatory capacity. 1091 50

Dendritic cells (DC) are potent antigen-presenting cells (APC). Ongoing preclinical and clinical studies exploit this capacity for the immunotherapy of tumors. We tested vaccinia virus (VV) as a vector to transduce human DC. Immature and mature DC were prepared from blood monocytes and infected with (1) recombinant VV expressing GFP to analyze infection rates, virus replication in DC and the effect of infection on DC phenotype and (2) recombinant VV expressing beta-galactosidase (betaGAL) under the control of viral early, intermediate and late promoters to analyze the poxvirusdriven gene expression. While the infection rate in DC was comparable to a permissive fibroblast cell line, viral betaGAL gene expression was limited to early promoters. Genes under the control of virus late promoters were not expressed by VV in DC, indicating an abortive infection. VV infection selectively reduced the surface expression of the costimulatory molecule CD80 and the DC maturation marker CD83 on mature DC while other surface molecules including CD86 and MHC remained unchanged. In line with this finding, there was a pronounced reduction in the capacity of VV-infected DC to stimulate allogeneic or autologous T cells in mixed lymphocyte reactions. Furthermore, VV infection inhibited the maturation of immature DC after exposure to proinflammatory cytokines. These results indicate that VV-derived vectors may have complex effects on their target cells. In the case of DC used for immunotherapy, this may be detrimental to their function as potent APC and particularly their capacity to activate T helper cells.
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PMID:Poxvirus as a vector to transduce human dendritic cells for immunotherapy: abortive infection but reduced APC function. 1102 96

Colony-stimulating factor 1 (CSF-1) regulates the survival, proliferation, and differentiation of mononuclear phagocytes. It is expressed as a secreted glycoprotein or proteoglycan found in the circulation or as a biologically active cell-surface glycoprotein. To investigate tissue CSF-1 regulation, CSF-1-null Csf1(op)/Csf1(op) mice expressing transgenes encoding the full-length membrane-spanning CSF-1 precursor driven by 3.13 kilobases of the mouse CSF-1 promoter and first intron were characterized. Transgene expression corrected the gross osteopetrotic, neurologic, weight, tooth, and reproductive defects of Csf1(op)/Csf1(op) mice. Detailed analysis of one transgenic line revealed that circulating CSF-1, tissue macrophage numbers, hematopoietic tissue cellularity, and hematopoietic parameters were normalized. Tissue CSF-1 levels were normal except for elevations in 4 secretory tissues. Skin fibroblasts from the transgenic mice secreted normal amounts of CSF-1 but also expressed some cell-surface CSF-1. Also, lacZ driven by the same promoter/first intron revealed beta-galactosidase expression in hematopoietic, reproductive, and other tissue locations proximal to CSF-1 cellular targets, consistent with local regulation by CSF-1 at these sites. These studies indicate that the 3.13-kilobase promoter/first intron confers essentially normal CSF-1 expression. They also pinpoint new cellular sites of CSF-1 expression, including ovarian granulosa cells, mammary ductal epithelium, testicular Leydig cells, serous acinar cells of salivary gland, Paneth cells of the small intestine, as well as local sites in several other tissues.
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PMID:Rescue of the colony-stimulating factor 1 (CSF-1)-nullizygous mouse (Csf1(op)/Csf1(op)) phenotype with a CSF-1 transgene and identification of sites of local CSF-1 synthesis. 1141 65