Mac-1在小鼠巨噬细胞识别白念珠菌中的作用

摘要

目的 探讨Mac-1在小鼠巨噬细胞识别白念珠菌中的作用.方法 以小鼠巨噬细胞系RAW264.7为靶细胞,与白念珠菌灭活酵母、活酵母细胞共培养,RT-PCR检测Mac-1 mRNA表达,western blot检测Mac-1蛋白表达,FITC包被白念珠菌后流式细胞技术检测巨噬细胞对其吞噬率,ELISA检测共培养上清细胞因子水平；siRNA靶向下调巨噬细胞Mac-1表达,检测共培养后吞噬率及细胞因子水平.结果 RAW264.7细胞与活酵母细胞、灭活酵母细胞共培养后,Mac-1 mRNA、蛋白表达无差异(P＞0.05),巨噬细胞的吞噬率分别为85.28％和84.90％,无明显差异性(P＞0.05)；共培养后,IL-2、IFN-γ等Th1型,IL-4、IL-10等Th2型均呈不同程度升高,但二组之间也无明显差异(P＞0.05).siRNA靶向下调RAW264.7细胞的Mac-1后,与白念珠菌共培养,巨噬细胞对白念珠菌的吞噬率下降为28.60％ (P＜0.05)；同时,巨噬细胞分泌细胞因子的水平下降.结论 在先天性免疫早期阶段,Mac-1为巨噬细胞识别、介导吞噬白念珠菌的模式识别受体之一；IL-2、IFN-γ等Th1型,IL-4、IL-10等Th2型细胞因子均参与巨噬细胞抗白念珠菌感染免疫.%The purpose was to evaluate the role of Mac-1 on murine macrophage in recognition of Candida albicans.The model for phagocytosis of Candida albicans inactivated yeast cells and live yeast cells by mouse macrophage cell line RAW 264.7 was established,the Mac-1 mRNA expression was detected by RT-PCR,Mac-1 protein expression was detected by western blot,phagocytosis rate was detected by flow cytometry,and the culture cytokine levels was detected by ELISA.The siRNAs interfered with Mac-1 on macrophage,targeting down the expression of Mac-1,phagocytosis rate and cytokine levels,were detected.It was found that the Mac-1 mRNA and protein expression and cytokine secretion was no significant difference after RAW264.7 cells co-cultured with inactivated yeast cells and live yeast cells (P＞ 0.05),with phagocytosis rates of 85.28 ％ and 84.90 ％,respectively (P＞0.05).After co-culture,IL-2,IFN-γ and other Th1-type crtokines,and IL-4,IL-10and other Th2-type cytokines showed different degrees of rise.Mac-1 on RAW264.7 cells was interfered by siRNA,and then co-cultured with Candida albicans.The phagocytic rate decreased to 28.60％ (P＜0.05).Meanwhile,the macrophages se crete cytokines decreased.Results indicate that in early stage of innate immunity,Mac 1 on macrophage is one of the pattern recognition receptors that participated in recognition and mediated phagocytosis of Candida albicans.Th1-type cytokines of IL2 and IFN-gamma,and Th2-type cytokines of IL-4 and IL-10 are involved in anti-infection immunity of macrophage resistance to Candida albicans.