【摘要】 目的分析载脂蛋白E基因(APOE)对RAW264.7细胞内的TLR信号通路的调节作用。方法克隆鼠APOE基因并建立表达APOE的RAW264.7稳定细胞系,使用各种Toll样受体(Toll-like receptors,TLR)配体进行刺激,用报告基因化学发光检测转录因子活性,流式细胞仪检测细胞表面免疫分子。结果在LPS刺激下,APOE基因抑制NF-κB的活性(P<0.05),但对AP-1活性有促进作用(P<0.05);在PolyI:C刺激下,APOE促进NF-κB和AP-1两者的活性(P<0.05)。在PGN刺激时,APOE明显上调B7-H1的表达,但对CD86、PD-1、CD11c及Gr-1的表达有抑制作用。结论APOE基因可以调节TLR信号通路中NF-κB的活性,也可调节多个具有免疫调节功能的表面分子的表达,这样APOE可能具有免疫调节功能。更多还原

【Abstract】 Objective To determine the effects of APOE on intracellular signal pathways mediated by different kinds of TLR.Methods We first cloned APOE gene,set up APOE tranfected stable cell line;and then detected the activity of both NF-κB and AP-1 transcription factors with chemiluminescence method.Using flow cytometric analysis,we investigated the expression of surface molecules in the APOE transfected RAW264.7 upon exposing to LPS,PolyI:C,PGN and BDNA.Results APOE not only affected the activity of NF-κB and AP-1 but also regulated the expression of costimulatory molecules induced by different kinds of TLR ligands.Indeed,APOE transfected RAW264.7 showed higher activity of NF-κB and AP-1 upon exposure to LPS and polyI: C as compared with the control(P<0.05) though NF-κB activity was little inhibited upon exposing to LPS(P<0.05).While APOE transfected RAW264.6 were stimulated by PGN,PolyI:C,LPS and BDNA respectively,APOE remarkably promoted the expression of B7-H1 induced by PGN;whereas the expression of CD86,PD-1,CD11c and Gr1 were lower in these APOE transfected stable cells.However,APOE did not effectively affect the expression of these costimulatory molecules induced by LPS,BDNA and PolyI:C.ConclusionAPOE affects specifically the expression of costimulatory molecules mediated by PGN and regulates the activity of NF-κB and AP-1,implying that APOE might beinvolved in the regulation of TLR-mediated immune responses.更多还原