自噬对巨噬细胞吞噬金黄色葡萄球菌的影响  

The effect of autophay on the Staphylococcus aureus phagocytosized by macrophages

作　　者：吕允相 吴惠梅[1] 方磊[1] 刘荣玉[1] 

机构地区：[1]安徽医科大学第一附属医院老年呼吸内科,合肥230022

出　　处：《安徽医科大学学报》2014年第6期706-710,共5页Acta Universitatis Medicinalis Anhui

基　　金：国家自然科学基金面上项目(编号:81270082;81170030);教育部高等学校博士学科点专项科研基金(编号:20113420110006);安徽省科技攻关项目(编号:12010402135);重点实验室计划项目(编号:1206c0805028)

摘　　要：目的探讨金黄色葡萄球菌(简称金葡菌)对巨噬细胞自噬的影响,并研究其在巨噬细胞吞噬病原微生物中的作用。方法以小鼠单核巨噬细胞系RAW264.7为研究对象,以磷脂酰肌醇3激酶(PI3K)抑制剂3-甲基腺嘌呤(3-MA)为干预药物,空白处理作为对照组,金葡菌感染作为实验组,3-MA干预作为抑制组。金葡菌感染细胞后,Western blot检测自噬蛋白Beclin1、LC3以及吞噬相关蛋白Rac1的表达,激光共聚焦显微镜观察自噬、吞噬现象。结果金葡菌感染RAW264.7 1 h后,实验组LC3Ⅱ和PI3K蛋白表达最强(P<0.05),抑制组Beclin1和LC3Ⅱ表达显著降低(P<0.05),自噬颗粒聚集显著减少(P<0.05),Rac1表达显著降低(P<0.05),同时,RAW264.7吞噬金葡菌数目显著减少(P<0.05)。结论金葡菌诱导的自噬增强了巨噬细胞吞噬能力,自噬抑制剂3-MA抑制PI3K活性的同时,减弱了巨噬细胞自噬吞噬金葡菌的能力。Objective To study the effect of Staphylococcus aureus on autophagy in macrophages and the role of au-tophagy in the pathogens phagocytosis by macrophages. Methods Mouse monocyte-macrophage cell line RAW264. 7 was used, before infecting by Staphylococcus aureus, RAW264. 7 cells were pretreated by phosphati-dylinositol3-kinase （PI3K） inhibitor, 3-MA. Blank treatment was served as control group, infected by Staphylococ-cus aureus was served as experimental group and pretreated by 3-MA was served as inhibited group. The protein ex-pression levels of LC3, Beclin1 and Rac1 were measured by Western blot, the process of autophagy and phagocyto-sis were viewed by Confocal Scanning Laser Microscope. Results The protein expression levels of LC3Ⅱ and PI3 K were increased after infected by Staphylococcus aureus for 1 h （ P〈0. 05 ） . Compared to that in experimental group, the protein expression levels of LC3Ⅱ and Beclin1（P〈0. 05）, the aggregation of autophagy puncta were significantly decreased in inhibited group （ P 〈0. 05 ） . Similarly, the protein level of Rac1 （ P 〈0. 05 ） and the phagocytosis of Staphylococcus aureus in RAW264 . 7 were significantly reduced in inhibited group （ P 〈0. 05 ） . Conclusion Autophagy induced by Staphylococcus aureus strengthens the phagocytosis of macrophages, and auto-phagy and phagocytosis in macrophages are down-regulated via inhibiting PI3K activity by 3-MA.

关 键 词：吞噬 自噬 巨噬细胞 磷脂酰肌醇3激酶 金黄色葡萄球菌 

分 类 号：R378.1[医药卫生—病原生物学]