microRNA-27a对树突状细胞表型及功能的影响

microRNA-27a regulates maturation process and cytokine in LPS-stimulated dendritic cells

目的:研究microRNA-27a(miR-27a)对脂多糖(Lipopolysaccharide,LPS)刺激的小鼠树突状细胞(Dendritic cell,DC)的成熟和细胞因子分泌的影响。方法:小鼠骨髓来源的未成熟树突状细胞(immature dendritic cell,im DC)转染miR-27a的模拟物(miR-27a mimics)后,用LPS刺激24 h,采用流式细胞仪检测其表面共刺激分子CD80、CD86及MHCⅡ表达,ELISA方法检测其上清中的IL-12p70及IL-10蛋白水平,RT-PCR方法检测其细胞内IL-12p40及IL-10 mRNA水平,混合淋巴细胞反应(MLR)检测其刺激T细胞增殖能力。结果:与未处理的im DC比较,LPS刺激24 h后的DC表面的共刺激分子CD80、CD86及MHCⅡ表达均显著增高(均P<0.001);LPS刺激24 h后,与对照组比较,转染miR-27a mimics细胞的共刺激分子CD80、CD86及MHCⅡ表达均显著降低(均P<0.001),且显著抑制IL-12分泌(P<0.01)、促进IL-10分泌(P<0.05),并显著减弱LPS刺激的DC促CD4+T细胞增殖的能力(P<0.01)。结论:miR-27a影响小鼠树突状细胞的成熟以及细胞因子的分泌。

Objective： To explore the effects of miR-27 a on the phenotype and cytokine secretion in LPS-stimulated dendritic cells. Methods： Murine bone marrow-derived dendritic cells were transfected with miR-27 a mimics and negative control mimics,and then stimulated by LPS for 24 hours. Dendritic cells exposed to LPS were collected for analysis of the DC immunophenotype by flow cytometry and supernatants were collected to determine cytokine lever. Moreover,the capability of stimulating allogeneic CD4＋T cell proliferation was measured by MLR（ mixed lymphocyte reaction）. Results： The levels of MHCⅡ,CD80,and CD86 were significantly increased in LPS-stimulated dendritic cells when compared with im DC（ P 〈0. 001）. Transfection with miR-27 a mimics resulted in significantly lower expression levels in levels of MHCⅡ,CD80,and CD86（ P 〈0. 001）. For cytokine secretion,transfection with miR-27 a mimics enhanced IL-10 production（ P 〈0. 01） and reduced the production of IL-12（ P 〈0. 05）. For MLR,transfection with miR-27 a mimics suppressed allogeneic CD4＋T cell proliferation. Conclusion： MiR-27 a may play critical roles in regulating the maturation process and cytokine secretion in LPS-stimulated dendritic cells.