NOD2在巨噬细胞对金黄葡萄球菌的炎性反应中的作用研究

NOD2 plays an important role in the inflammatory responses of macrophages to Staphylococcus aureus

目的 通过观察对比巨噬细胞NOD2基因沉默前后对金黄葡萄球菌感染的免疫应答,了解NOD2基因在金黄葡萄球菌感染巨噬细胞过程中所起的作用.方法 采用real-time RT-PCR的方法检测巨噬细胞NOD2基因在金黄葡萄球菌感染时的表达情况,合成针对NOD2的siRNA并干扰巨噬细胞.采用ELISA、流式细胞术等方法观察NOD2基因沉默对其在金黄葡萄球菌感染时的吞噬能力、细胞因子分泌水平、核转录因子（NF-κB）活化水平、细胞凋亡的影响.结果 金黄葡萄球菌感染巨噬细胞可引起细胞内NOD2表达增高.巨噬细胞NOD2基因沉默可导致其吞噬金黄葡萄球菌的能力降低,分泌细胞因子水平降低,NF-κB激活不足.金黄葡萄球菌可以引起巨噬细胞发生凋亡,凋亡率随时间延长而升高.结论 在金黄葡萄球菌感染巨噬细胞的过程中,位于细胞内的模式识别受体NOD2在病原体识别、信号转导、NF-κB激活中发挥关键作用.

Objective To investigate the effects of NOD2 on inflammatory responses of macrophages to Staphylococcus aureus. Methods Real-time RT-PCR detected NOD2 gene expression of macrophages infected by S. aureus. Synthesis of siRNA against NOD2 and interfere with macrophages, observed the effects of NOD2 gene silencing to phagocytosis of 5. aureus, cytokine secretion, activation of nuclear transcription factors, cell apoptosis of the macrophages infected by S. aureus using F.I .IS A, flow cytometry etc. Results S. aureus infection of macrophages can cause increased expression of intracellular NOD2. NOD2 gene silencing of macrophage lead to the decreased ability of phagocytosis with S. aureus, the lower levels of cytokines secretion, deficiencies of NF-κB activation. S. aureus can cause macrophage apoptosis, with the apoptosis rate increased with time. Conclusion The intracellular pattern recognition receptor NOD2 play a key role in pathogen recognition, signal transduction, activation of nuclear transcription factors in the process of macrophages infected by S. aureus.