Pseudomonas aeruginosa promotes autophagy to suppress macrophage-mediated bacterial eradication
Pseudomonas aeruginosa promotes autophagy to suppress macrophage-mediated bacterial eradication
复制标题
铜绿假单胞菌促进自噬抑制巨噬细胞介导的细菌根除
DOI：
10.1016/j.intimp.2016.04.044
复制
发表时间：
2016-09-01
影响因子：
5.6
通讯作者：
Wu, Minhao
中科院分区：
文献类型：
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作者：
Wu, Yongjian;Li, Dandan;Wu, Minhao
目的：探讨自噬在巨噬细胞介导的吞噬和胞内杀伤铜绿假单胞菌（PA）中的作用。PA是一种常见的细胞外细菌，常引起各种机会性感染。方法：用PA感染巨噬细胞或用酶酶生物颗粒刺激巨噬细胞。采用荧光显微镜和Western blot检测LC3的自噬情况。采用平板计数法、流式细胞术和免疫荧光染色法检测细胞吞噬和杀伤效果。分别用PCR、流式细胞术和Griess反应检测吞噬受体表达、ROS生成和NO生成。结果：PA感染诱导小鼠和人巨噬细胞自噬激活。雷帕霉素或饥饿诱导的自噬通过下调吞噬受体表达显著抑制PA内化，并通过减少巨噬细胞中ROS和NO的产生抑制PA的胞内杀伤。而自噬分子ATG7或Beclin1的敲低则增强了巨噬细胞介导的吞噬作用和细胞内PA的杀伤。此外，共聚焦显微镜数据显示，自噬诱导减少了巨噬细胞中吞噬体和吞噬溶酶体的数量。结论：我们的研究表明，PA促进自噬抑制巨噬细胞介导的细菌吞噬和细胞内杀伤。这些发现证明了PA采用的一种新的免疫逃避机制，可能为PA感染性疾病的治疗提供潜在的策略。(C) 2016 Elsevier B.V.版权所有
Objectives: To explore the role of autophagy on macrophage-mediated phagocytosis and intracellular killing of Pseudomonas aeruginosa (PA), a common extracellular bacterium which often causes various opportunistic infections.Methods: Macrophages were infected with PA or stimulated with zymosan bioparticles. Autophagy was tested by fluorescent microscopy and Western blot for LC3. Phagocytosis and killing efficiency were assessed by plate count assay, flow cytometry or immunofluorescent staining. Phagocytic receptor expression, ROS generation and NO production were examined by PCR, flow cytometry and Griess reaction, respectively.Results: PA infection induced autophagy activation in both mouse and human macrophages. Induction of autophagy by rapamycin or starvation significantly inhibited PA internalization by downregulating phagocytosis receptor expression, and suppressed intracellular killing of PA via reducing ROS and NO production in macrophages. While knockdown of autophagy molecules ATG7 or Beclin1 enhanced macrophage-mediated phagocytosis and intracellular killing of PA. Additionally, confocal microscopy data showed that induction of autophagy reduced the number of phagosomes and phagolysosomes in macrophages after stimulation With zymosan bioparticles.Conclusions: Our study suggested that PA promotes autophagy to suppress macrophage-mediated bacterial phagocytosis and intracellular killing. These insights demonstrated a novel immune evasion mechanism employed by PA, which may provide potential therapeutic strategies of PA infectious diseases. (C) 2016 Elsevier B.V. All rights reserved.