【摘要】 为研究活化诱导的凋亡淋巴细胞来源的DNA(凋亡DNA)对小鼠巨噬细胞的体外活化作用,用ConA活化小鼠脾脏淋巴细胞并诱导其凋亡,将AnnexinV+凋亡细胞来源的DNA定义为凋亡DNA,而正常淋巴细胞来源的DNA定义为正常DNA,分别与小鼠巨噬细胞株RAW264.7体外孵育48 h,然后用碘化丙啶(PI)染色方法观察细胞吞噬的DNA平均荧光强度(MFI),流式细胞仪测定细胞表面分子的表达,ELISA检测II型干扰素(IFN-γ)、白细胞介素12(IL-12)和肿瘤坏死因子(TNF-α)的分泌情况。结果显示:凋亡DNA和正常DNA都能被RAW264.7有效地吞噬;然而,凋亡DNA较正常DNA能显著上调RAW264.7细胞表面MHC II类分子以及协同刺激分子CD40、CD80、CD86的表达,同时能够诱导细胞分泌高水平的IFN-γ、IL-12和TNF-α。表明正常DNA对巨噬细胞无活化作用,而凋亡DNA对巨噬细胞有很强的活化作用,可上调巨噬细胞的APC功能并促使其分泌多种细胞因子。提示凋亡的自身DNA作为免疫原,可有效活化巨噬细胞。更多还原

【Abstract】 To observe the activation effect of DNA derived from apoptotic lymphocytes on murine macrophage in vitro,splenocytes of BALB/ c mice activated by ConA were induced apoptosis and the DNA derived from Annexin-V+ apoptotic cells was defined as apoptotic DNA.Macrophage cell line RAW264.7 was incubated for 48 hours with apoptotic DNA and normal splenocytes derived DNA(normal DNA) respectively.The levels of DNA uptake by RAW264.7 represented as the mean fluorescence intensity(MFI) were assayed with PI staining,and the cell surface expression of MHC class II and costimulatory molecules CD40,CD80,CD86 was analyzed by FACS.The production of IFN-γ,IL-12 and TNF-α by RAW264.7 was assessed by ELISA.It was showed that apoptotic DNA and normal DNA could be uptaken by RAW264.7 cells,and the MFI level of both was higher than that of control.However,apoptotic DNA could more evidently upregulate MHC class II and costimulatory molecules on RAW264.7 cells and stimulate higher secretory level of IFN-γ,IL-12 and TNF-α,compared to normal DNA.These results suggest that apoptotic DNA can efficiently activate murine macrophage,enhance the APC function of macrophage and the secretion of cytokines.It indicates that apoptotic DNA is an important immunogen to activate macrophage.更多还原