Rupp B, Löhning M, Werenskiold A K
Institut für Allgemeine Pathologie und Pathologische Anatomie der Technischen Universität, München, Germany.
Eur J Immunol. 2000 Oct;30(10):2954-61. doi: 10.1002/1521-4141(200010)30:10<2954::AID-IMMU2954>3.0.CO;2-S.
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.
业已证实，肥大细胞可在体内改变其颗粒糜蛋白酶和组织蛋白酶的表达。在体外，迄今为止仅证实糜蛋白酶存在可逆的细胞因子调节作用。我们现在展示了在连续的小鼠肥大细胞系L138.8A中，组织蛋白酶MMCP - 6和MMCP - 7以及糜蛋白酶MMCP - 1、MMCP - 2和MMCP - 4存在可逆的细胞因子调节表达。当在白细胞介素 - 3中培养时，L138.8A肥大细胞缺乏肥大细胞特异性蛋白酶的mRNA表达，通过流式细胞术检测，分别仅有49%和41%的细胞为c - kit +和FcepsilonRI +。干细胞因子诱导糜蛋白酶MMCP - 4以及组织蛋白酶MMCP - 6和MMCP - 7的合成，并使c - kit +和FcepsilonRI +的L138.8A细胞比例增加至>70%。在白细胞介素 - 3或白细胞介素 - 9存在的情况下，干细胞因子诱导的组织蛋白酶表达受到抑制，在去除干细胞因子后则逆转。白细胞介素 - 9或白细胞介素 - 3/白细胞介素 - 10促进阿尔新蓝阳性颗粒的形成，并使c - kit +和FcepsilonRI +的L138.8A细胞比例增加至>90%。白细胞介素 - 9进一步诱导糜蛋白酶MMCP - 1、MMCP - 2和MMCP - 4的表达。因此，未成熟的肥大细胞系L138.8A具有调节组织蛋白酶和糜蛋白酶表达的能力，并且代表了第一个在体外分析组织蛋白酶表达分子调节的模型系统。
