title: New aspects in the synthesis and secretion of lysozyme by cultured human monocyte cell lines.
abstract: The main purpose of this study was to investigate lysozyme synthesis and secretion in three human monocyte cell lines: U-937, HL-60, and THP-1, using sensitive fluorescence-based assay of lysozyme activity. PMA and hIFN-gamma were evaluated for inducing lysozyme activity. Using well-defined cell lines from the cell culture collection, no lysozyme activity could be detected in the cultured U-937 cells either with or without addition of the inducing factors. These data suggested, contrary to previous reports, that U-937 cell line cannot synthesize or secrete active lysozyme. THP-1 and HL-60 cells were proved to produce enzymatically active lysozyme in increasing amounts with the time course. PMA and hIFN-gamma had no significant inducing effect on the production or the release of active lysozyme in THP-1 and HL-60 cells. We showed inhibiting effect of PMA and hIFN-gamma on the lysozyme activity, particularly in HL-60 cell line.
authors.affiliation: Department of Pharrmaceutical Biology, Institute of Pharmacy, Free University of Berlin, Königin-Luise-Str. 2+4, 14195, Berlin, Germany.
authors.forename: Racha
authors.initials: R
authors.lastname: Helal
authors.forename: Matthias F
authors.initials: MF
authors.lastname: Melzig
mesh_terms: D002454:Cell Differentiation; D002460:Cell Line; D018922:HL-60 Cells; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D009113:Muramidase / Q000096:biosynthesis*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D007371:Interferon-gamma; D009113:Muramidase; D013755:Tetradecanoylphorbol Acetate