NOD2信号对人肺泡巨噬细胞抗结核分枝杆菌活性的影响及机制研究

NOD2 stimulation enhances the innate immunity against Mycobacterium tuberculosis in human alveolar macrophages

目的研究核苷酸结合寡聚化结构域2(NOD2)信号在天然抗结核免疫中的作用。方法平板计数法评价NOD2信号对人肺泡巨噬细胞杀结核分枝杆菌效应的影响;流式细胞术和聚合酶链反应(PCR)检测NOD2的表达;实时荧光定量PCR检测一氧化氮合成酶(iNOS)和DEF4B mRNA的表达水平;还原型二氯荧光素(DFCH)探针法测定活性氧(ROS)水平。结果NOD2信号增强了人肺泡巨噬细胞对结核分枝杆菌H37RV的杀灭。NOD2信号刺激后,人肺泡巨噬细胞中一氧化氮(NO)的分泌和DEF4B的表达均有所增加,但ROS水平变化不明显。结论 NOD2可能通过诱导NO和抗菌肽DEF4B的产生参与了早期的抗结核感染免疫。

Objective To evaluate the role of nucleotide‐binding oligomerization domain 2（NOD2） stimulation in innate immuni‐ty against M ycobacterium tuberculosis .Methods Plate counting as used to evaluate the effect of resisting M ycobacterium tubercu‐losis in human alveolar macrophages .Intracellular NOD2 expression were detected by flow cytometry .Quantitative real‐time PCR was performed to determine the NOD2 ,inducible nitric oxide synthase（iNOS） ,and DEF4B mRNA expression levels using the com‐parative threshold cycle method of relative quantitation .Reactive oxygen species（ROS） were detected by the DFCH probe .Results NOD2 stimulation enhanced the control of intracellular mycobacterial growth in human alveolar macrophages .Although ROS con‐centration did not changed ,the secretion of Nitro Oxygen and the expression of cathelicidin DEFB4 were significantly increased fol‐lowing NOD2 stimulation in human alveolar macrophages .Conclusion NOD2 stimulation may be involved in the early innate con‐trol of Mycobacterium tuberculosis primary infections inducing the generation of Nitro Oxygen and the peptides cathelicidin DEFB4 .