枯草芽孢杆菌刺激小鼠肠上皮细胞分泌的IL-33在活化树突状细胞中发挥重要作用

The important role of IL-33 secreted from Bacillus subtilis-stimulated intestinal epithelial cells in mouse dendritic cell activation

【目的】枯草芽孢杆菌能有效诱导肠道黏膜免疫应答,但活化黏膜下树突状细胞(DC)的具体机制不完全清楚。【方法】本研究首先用不同浓度枯草芽孢杆菌刺激小鼠肠上皮CMT93细胞,用荧光定量PCR和ELISA检测细胞因子表达水平,然后将枯草芽孢杆菌刺激细胞的培养上清与小鼠骨髓源树突状细胞(BMDC)进行共孵育,用流式细胞术检测BMDC活化标志,最后用RNA干扰技术证明IL-33在活化BMDC中的作用。【结果】枯草芽孢杆菌能显著刺激CMT93细胞分泌IL-6、IL-33和IFN-g等细胞因子,对刺激IL-33表达呈现剂量依赖性;枯草芽孢杆菌刺激CMT93细胞产生的细胞因子能活化BMDC,在RNA干扰IL-33基因表达和枯草芽孢杆菌刺激后,CMT93细胞培养上清活化BMDC的能力显著降低。【结论】本研究结果表明枯草芽孢杆菌刺激肠上皮细胞产生的IL-33在BMDC活化中具有重要作用。

[Objective]Bacillus subtilis can induce efficient intestinal mucosal immune responses,but the detailed mechanism for dendritic cell activation remains to be defined.[Methods]Mouse intestinal epithelial CMT93 cells were stimulated with different concentra amyloliquefaciens tions of Bacillus subtilis and the cytokine expression was measure by quantitative RT-PCR and ELISA.After incubation with the cytokine-containing cell culture medium,activation of mouse bone marrow-derived dendrites(BMDC)was analyzed by flow cytometry and the role of IL-33 in BMDC activation was confirmed by RNA interference.[Results]Bacillus subtilis could significantly stimulate CMT93 cells to secret IL-6,IL-33 and IFN-g,and induce the IL-33 selection in a dose-dependent manner.The cytokine-containing cell medium could significantly activate BMDC.After interfering IL-33 gene expression and stimulation with Bacillus subtilis,however,the ability of CMT93 cell medium for BMDC activation was significantly reduced.[Conclusion]These data suggest that IL-33 from Bacillus subtilis-stimulated mouse intestinal epithelial cells plays an important role in the dendritic cell activation.