STUDY ON THE IMMUNOMODURATORY ACTION OF BILE ACIDS

胆汁酸的免疫调节作用主要涉及：1)调节MHC I类和II类基因表达，2)糖皮质激素受体与胆汁酸的相互作用，3)胆汁酸对T细胞信号传导的影响。1)胆汁酸可上调MHC I类基因的表达，其机制可能是激活蛋白激酶C。目前，胆汁酸相关蛋白激酶C的异构体分析正在进行中。关于MHC II类基因的表达，胆酸熊去氧胆酸抑制ifn - γ的上调作用，这种抑制被证明是由熊去氧胆酸介导的不依赖配体的糖皮质激素受体激活。2)胆汁酸熊去氧胆酸在缺乏配体的情况下可激活胞质内潜伏的糖皮质激素受体进入功能物种。其分子机制尚不清楚。3)我们已经获得了初步的数据，表明胆汁酸对抗原活化T细胞内信号事件的影响。

The immunomodulatory action of bile acids was studied with special reference to1) regulation of MHC class I & II gene expression,2) interplay between the glucocorticoid receptor and bile acids,3) effects of bile acids on T cell signaling.1) Bile acids were shown to upregulate gene expression of MHC class I,the mechanism for which is suggested to be activation of protein kinase C.Currently, isoform analysis of bile acidrelated protein kinase C is ongoing. Concerning MHC class II gene expression, bile acid ursodeoxycholic acid represses upregulatory effect of IFN-gamma, and this repression is shown to be mediated ligand-independent activation of the glucocorticoid receptor by ursodeoxycholic acid.2) bile acid ursodeoxycholic acid is shown to activated cytosolic latent glucocorticoid receptor into functional species in the absence of ligands. The molecular mechanism is unknown.3) Already we have obtained preliminary data suggesting influence of bile acids on the intracellular signaling events in antigen-activated T cells.