ProbioticEscherichia coliNissle 1917-derived outer membrane vesicles enhance immunomodulation and antimicrobial activity in RAW264.7 macrophages
ProbioticEscherichia coliNissle 1917-derived outer membrane vesicles enhance immunomodulation and antimicrobial activity in RAW264.7 macrophages
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益生菌大肠杆菌 Nissle 1917 衍生的外膜囊泡增强 RAW264.7 巨噬细胞的免疫调节和抗菌活性
DOI：
10.1186/s12866-020-01953-x
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发表时间：
2020-08-27
期刊：
影响因子：
4.2
通讯作者：
Yang, Mingming
中科院分区：
文献类型：
--
作者：
Hu, Rujiu;Lin, Hua;Yang, Mingming
益生菌大肠杆菌1917 （EcN）已被广泛研究用于治疗肠道炎症性疾病和感染性腹泻，但它们与宿主沟通的机制尚不清楚。外膜囊泡（Outer membrane vesicles, OMVs）是由革兰氏阴性菌产生并将微生物分子传递到宿主体内遥远的靶细胞的物质，在介导细菌与宿主的通讯中起着非常重要的作用。在这里，我们的目的是研究ecn衍生的omv （ecn_omv）是否可以介导巨噬细胞的免疫调节。结果本研究通过电镜、纳米颗粒跟踪和蛋白质组学分析对ecn_omv进行了表征，并通过共聚焦荧光显微镜证实了ecn_omv可以被RAW 264.7巨噬细胞内化。适当浓度的ecn_omv刺激可促进RAW264.7细胞的增殖、免疫相关酶活性和吞噬功能。此外，在体外实验中，EcN_OMVs诱导的抗炎反应（IL-10）比促炎反应（IL-6和tnf - α）更多，并调节th1极化细胞因子（IL-12）和th2极化细胞因子（IL-4）的产生。EcN_OMVs有效提高了RAW 264.7巨噬细胞的抗菌活性。结论ecn_omv可以调节宿主免疫细胞的功能，这将丰富现有的EVs作为益生菌与宿主沟通的重要机制的知识体系。
Background ProbioticEscherichia coliNissle 1917 (EcN) has been widely studied for the treatment of intestinal inflammatory diseases and infectious diarrhea, but the mechanisms by which they communicate with the host are not well-known. Outer membrane vesicles (OMVs) are produced by Gram-negative bacteria and deliver microbial molecules to distant target cells in the host, which play a very important role in mediating bacteria-host communication. Here, we aimed to investigate whether EcN-derived OMVs (EcN_OMVs) could mediate immune regulation in macrophages. Results In this study, after the characterization of EcN_OMVs using electron microscopy, nanoparticle tracking and proteomic analyses, we demonstrated by confocal fluorescence microscopy that EcN_OMVs could be internalized by RAW 264.7 macrophages. Stimulation with EcN_OMVs at appropriate concentrations promoted proliferation, immune-related enzymatic activities and phagocytic functions of RAW264.7 cells. Moreover, EcN_OMVs induced more anti-inflammatory responses (IL-10) than pro-inflammatory responses (IL-6 and TNF-alpha) in vitro, and also modulated the production of Th1-polarizing cytokine (IL-12) and Th2-polarizing cytokine (IL-4). Treatments with EcN_OMVs effectively improved the antibacterial activity of RAW 264.7 macrophages. Conclusions These findings indicated that EcN_OMVs could modulate the functions of the host immune cells, which will enrich the existing body of knowledge of EVs as an important mechanism for the communication of probiotics with their hosts.