title: Reversible expression of tryptases in continuous L138.8A mast cells.
abstract: It has been established that mast cells can alter their expression of granule chymases and tryptases in vivo. In vitro, a reversible cytokine regulation has so far only been demonstrated for chymases. We now show a reversible and cytokine-regulated expression of the tryptases MMCP-6 and MMCP-7 and of the chymases MMCP-1, MMCP-2 and MMCP-4 in the continuous murine mast cell line L138.8A. The L138.8A mast cells lacked expression of mRNA for mast cell-specific proteases when cultured in IL-3, and only 49% and 41% of the cells were c-kit+ and FcepsilonRI+, respectively, by flow cytometry. Kit-ligand/stem cell factor induced synthesis of the chymase MMCP-4 and the tryptases MMCP-6 and MMCP-7 and increased the fraction of c-kit+ and FcepsilonRI+ L138.8A cells to >70%. Kit-ligand-induced tryptase expression was suppressed in the presence of IL-3 or IL-9, and reversed after withdrawal of kit-ligand. IL-9 or IL-3/IL-10 promoted the formation of Alcian blue+ granules and increased the fraction of c-kit+ and FcepsilonRI+ L138.8A cells to >90%. IL-9 further induced the expression of the chymases MMCP-1, MMCP-2 and MMCP-4. Thus, the immature mast cell line L138.8A has the capacity to modulate both tryptase and chymase expression and represents the first model system to analyze the molecular regulation of tryptase expression in vitro.
authors.affiliation: Institut für Allgemeine Pathologie und Pathologische Anatomie der Technischen Universität, München, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Rupp
authors.forename: M
authors.initials: M
authors.lastname: Löhning
authors.forename: A K
authors.initials: AK
authors.lastname: Werenskiold
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D053818:Chymases; D003594:Cytoplasmic Granules / Q000201:enzymology; D004790:Enzyme Induction / Q000187:drug effects; D053804:Granzymes; D016298:Hematopoietic Cell Growth Factors / Q000494:pharmacology*; D016753:Interleukin-10 / Q000494:pharmacology; D007377:Interleukin-3 / Q000494:pharmacology; D016906:Interleukin-9 / Q000494:pharmacology; D008407:Mast Cells / Q000187:drug effects / Q000201:enzymology*; D051379:Mice; D008807:Mice, Inbred BALB C; D019009:Proto-Oncogene Proteins c-kit / Q000187:drug effects / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D017455:Receptors, IgE / Q000502:physiology; D011994:Recombinant Proteins / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000096:biosynthesis* / Q000235:genetics; D019089:Stem Cell Factor / Q000494:pharmacology; D053802:Tryptases
chemical_list: D016298:Hematopoietic Cell Growth Factors; D007377:Interleukin-3; D016906:Interleukin-9; D012333:RNA, Messenger; D017455:Receptors, IgE; D011994:Recombinant Proteins; D019089:Stem Cell Factor; C509190:Tpsb2 protein, mouse; D016753:Interleukin-10; D019009:Proto-Oncogene Proteins c-kit; D053804:Granzymes; C509214:Gzmb protein, mouse; D012697:Serine Endopeptidases; C083294:chymase 2; C066932:mast cell protease 4; D053818:Chymases; C509229:Cma2 protein, mouse; C509222:Tpsab1 protein, mouse; D053802:Tryptases