沙眼衣原体感染活化NOD1信号通路的研究

目的:探索沙眼衣原体(Chlamydia trachomatis,Ct)持续感染状态下,NOD1、IL-6及STAT3分子的表达情况和相互关系。方法:利用HeLa229细胞或STAT3基因沉默的HeLa229细胞,分别建立沙眼衣原体的急性感染和持续感染模型;应用Western Blot及ELISA等方法检测不同感染状态下STAT3及NOD1蛋白表达水平以及细胞因子IL-6的分泌水平。结果:HeLa229细胞在Ct感染状态下,STAT3和NOD1以及IL-6表达水平均升高,且于持续感染状态下的升高较急性感染状态下的升高更明显;沉默STAT3基因后,Ct感染的细胞NOD1及IL-6的表达水平下降明显。结论:HeLa229细胞在Ct持续感染状态下,STAT3能上调NOD1及IL-6表达水平,上述分子间存在NOD1-IL-6-STAT3正反馈信号通路。

A Study on the Activation of NOD1 Signaling Pathway Induced by Chlamydia trachomatis Infection

Objective:To study the expression level of NOD1,IL-6 and STAT3 in the model of Chlamydia trachomatis (Ct) persistent infection,and explore the connection and effects between those molecules.Methods:We established the acute infection model and the persistent infection model by using the HeLa229 or stable STAT3 knockdown HeLa229 cell line.Western Bolt and ELISA were performed respectively to detect the expression levels of STAT3 and NOD1 and the secretion of inflammatory cytokines IL-6 in the different infection states.Results:We found that the expression levels of STAT3,NOD1 and IL-6 were up regulated in the acute and persistent infection models,and there was even higher expression level in the persistent infection model.Our study suggested that the levels of IL-6 and NOD1 declined significantly in the persistent infection model when the gene of STAT3 was silenced.Conclusions:The signal transduction pathway of STAT3-NOD1-IL-6 was activated in the persistent Ct infection model.STAT3 up-regulated the expression of NOD1 and promoted the secretion of IL-6 to intensify the intracellular inflammation.