黄芩苷抑制沙眼衣原体宿主细胞MHCⅠ、CD1d下调的机制

Baicalin inhibits downregulation of MHCⅠand CD1d expression in Chlamydia trachomatisinfected cells

目的:研究黄芩苷对沙眼衣原体体外生长的影响,并探究其对感染细胞MHC分子表达影响的可能机制。方法:用HeLa细胞培养沙眼衣原体Ct,选取不同的时间点及不同浓度的黄芩苷干预,免疫荧光检测包涵体数目及大小;Western blot检测空白组、对照组及不同黄芩苷浓度干预组CPAF、RFX5和USF-1蛋白表达水平;流式细胞术分别检测各组细胞表面MHCⅠ类分子(HeLa细胞)及CD1d分子(PURL原代细胞)表达情况。结果:黄芩苷明显抑制包涵体形成的数目及大小,降低活化的CPAF含量及抑制RFX5、USF-1的降解,抑制感染细胞表面MHCⅠ、CD1d表达下调。结论:黄芩苷能抑制沙眼衣原体体外生长,而CPAF很可能是黄芩苷抑制感染细胞表面MHC分子及CD1d分子下调的干预靶点。

OBJECTIVE To investigate the effect of baicalin on Chlamydia trachomatis （Ct） growth in vitro potentinal mechanism of regulation of MHC expression level in infected cells treated with baicalin. METHODS and explore the Ct were propa- gated in HeLa cells and treated with baicalin at various time points or different concentration prior to observing inclusions using microscope. The expression level of CPAF, RFX and USF proteins, from mock-infected or Ct-infected cells treated with differ ent concentration of baicalin, were detected with Western blot. MHC I in HeLa cells and CDld in penile urethral cells were an alyzed with Flow cytometry respectively. RESULTS The number and size of inclusions were markedly reduced when cultures were treated with baicalin. The expression of active-CPAF and the degration of both RFX and USF were suppressed distinctlyin baiealin-treated groups. Downregulation of MHC and CDld expression in cell surface was disrupted by co incubation with baicalin. CONCLUSION Baicalin can inhibit the growth of Chlamydia trachomatis in vitro ; the CPAF is the probable inter- fering target of baicalin to inhibit downregulation of MHC and CD1 d expression.