TLRs信号通路在青藤碱诱导大鼠imDC中的作用

Preliminary study on the role of TLRs signaling pathway on sinomenine-induced imDCs in rats

目的探讨青藤碱(SIN)在诱导大鼠来源树突状细胞(DCs)中发挥免疫抑制作用的可能机制。方法体外培养Wistar大鼠骨髓来源前体细胞,显微镜下观察青藤碱处理DCs(青藤碱修饰组,SIN组)与常规诱导DCs(常规诱导组,对照组)的形态学差异,利用流式细胞术检测DCs的CD表型特点。以脂多糖(LPS)刺激诱导DCs成熟,采用流式细胞术检测青藤碱对LPS诱导的树突状细胞表面Toll样受体(TLR)2、TLR3、TLR4表达的影响。结果常规诱导组可见细胞呈葡萄串样的细胞集落或悬浮生长,细胞表面颗粒感明显;而青藤碱诱导组细胞集落在一起,细胞体积、形态无明显变化。常规诱导组中DCs表面CD80、CD86的相对表达量为70.7%、71.3%,而SIN组中DCs表面CD80、CD86的相对表达量为51.7%、49.4%。SIN+LPS组DCs表面TLRs相对表达量TLR2(51.2±0.34)%、TLR3(50.3±0.14)%、TLR4(52.1±0.16)%,较单纯LPS组DCs表面相应TLRs相对表达量[(94.35±0.16)%、(97.55±0.16)%、(94.6±0.12)%]明显降低。结论SIN可能可以通过抑制TLRs信号通路抑制DCs成熟,从而诱导免疫耐受。

Objective To investigate the mechanism of sinomenine(SIN)in inducing the immunosuppressive effects of rat-derived dendritic cells(DCs).Methods The bone marrow-derived precursor cells from Wistar rats were cultured in vitro.The morphological differences between sinomenine treated DCs(sinomenine modified group,SIN group)and conventional induced DCs(conventional induced group,control group)were observed under microscope.The CD phenotype of DCs was detected by flow cytometry.DCs were induced maturation by lipopolysaccharides(LPS)stimulation.The impact of SIN on the expressions of Toll-like receptor(TLR)2,TLR3 and TLR4 on the DCs surface were detected by flow cytometry.Results In the conventional induction group,the cells showed clusters or suspension growth,with obvious granular sense on the cell surface;while in the sinomenine induction group,the cells were clustered together,with no significant change in cell volume and morphology.The relative expressions of CD80 and CD86 were 70.7%and 71.3%in the conventional induction group,while 51.7%and 49.4%in the SIN group.The relative expression of TLRs on DCs in SIN+LPS group was TLR2(51.2±0.34)%,TLR3(50.3±0.14)%,TLR4(52.1±0.16)%,which were significantly lower than those in LPS group[(94.35±0.16)%,(97.55±0.16)%,(94.6±0.12)%].Conclusions SIN may induce immune tolerance by inhibiting the maturation of DCs via inhibiting the TLRs signaling pathways.