Mac-1在小鼠巨噬细胞识别白念珠菌中的作用

Role of Mac-1on murine macrophage in recognition of Candida albicans

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-1mRNA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-1mRNA、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。

ABSTRCT： In order to evaluate the role of Mac-1 on murine macrophage in recognition of Candida albicans. The model for the phagocytosis of Candida albicans inactivated yeast cells and live yeast cells by mouse macrophage cell line RAW264.7 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, culture cytokine levels was detected by ELISA. The siRNAs targeting interfere 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）, the phagocytosis rate was 85.28% and 84.90% （P〉0.05）. After co-culture, IL-2, IFN-γ and other Th1-type crtokines, IL-4, IL-10 and other Th2-type cytokines showed different degrees of rise. Mac-1 on RAW264.7 cells was interferenced by siRNA, then co-cultured with Candida albicans, phagocytic rate decreased to 28.60% （P〈0.05）. Meanwhile, the macrophages secrete cytokines decreased. The results indicate that in early stage of innate immunity, Mac-1 on macrophage is one of the pattern recognition receptors that participated recognition and mediated phagocytosis of Candida albicans. Th1-type cytokines of IL-2, IFN-gamma, Th2-type cytokines of IL-4, IL-10 are involved in anti-infection immunity of macrophage resistance to Candida albicans.