Stimulator of Interferon Genes Promotes Host Resistance Against Pseudomonas aeruginosa Keratitis.
Stimulator of Interferon Genes Promotes Host Resistance Against Pseudomonas aeruginosa Keratitis.
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干扰素基因刺激剂促进宿主对铜绿假单胞菌角膜炎的抵抗力
DOI：
10.3389/fimmu.2018.01225
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发表时间：
2018
影响因子：
7.3
通讯作者：
Wu M
中科院分区：
文献类型：
--
作者：
Chen K;Fu Q;Liang S;Liu Y;Qu W;Wu Y;Wu X;Wei L;Wang Y;Xiong Y;Wang W;Wu M
铜绿假单胞菌（PA）是细菌性角膜炎的主要原因，尤其是在那些戴接触透镜和免疫功能低下的人中。一旦入侵的病原体被表达在先天免疫细胞上的模式识别受体识别，先天免疫反应被激发，发挥宿主防御功能，这是对抗PA感染的第一道防线。干扰素基因刺激因子（stimulator of interferon genes，STING）作为细胞质DNA正义信号的汇聚点，参与了宿主与病原菌的相互作用。然而，STING在调节PA诱导的角膜炎症和细菌清除中的作用仍然未知。我们的数据表明STING在PA角膜炎小鼠模型和体外培养的巨噬细胞中被激活，通过Western印迹、免疫染色和流式细胞术指示。为了探讨STING在PA角膜炎中的作用，我们在体内和体外实验中分别用siRNA沉默STING和2′，3 ′-cGAMP激活STING，体内实验发现STING促进宿主抵抗PA感染。为探讨STING对PA角膜炎具有保护作用的原因，分别采用实时荧光定量PCR和细菌平板计数法检测了STING对PA角膜炎炎症细胞因子分泌和细菌载量的影响。我们的数据表明，STING抑制炎症细胞因子的产生，并增强PA角膜炎小鼠模型和PA感染的巨噬细胞中的细菌清除。为进一步研究其杀菌机制，分别采用Western blot、免疫荧光和实时荧光PCR检测丝裂原活化蛋白激酶（MAPK）磷酸化、核因子-κB（NF-κB）核转位和杀菌机制。我们的数据表明STING通过抑制NF-κB活性和增强诱导型NO合酶表达来抑制炎性细胞因子表达，这是一种氧依赖性杀菌机制。总之，本研究表明STING通过抑制角膜炎症和增强细菌杀灭，促进宿主对PA角膜炎的抵抗，并在PA感染的角膜疾病中发挥保护作用。
Pseudomonas aeruginosa (PA) is the leading cause of bacterial keratitis, especially in those who wear contact lens and who are immunocompromised. Once the invading pathogens are recognized by pattern recognition receptors expressed on the innate immune cells, the innate immune response is stimulated to exert host defense function, which is the first line to fight against PA infection. As a converging point of cytosolic DNA sense signaling, stimulator of interferon genes (STING) was reported to participate in host–pathogen interaction. However, the role of STING in regulating PA-induced corneal inflammation and bacterial clearance remains unknown. Our data demonstrated that STING was activated in murine model of PA keratitis and in in vitro-cultured macrophages, indicated by Western blot, immunostaining, and flow cytometry. To explore the role of STING in PA keratitis, we used siRNA to silence STING and 2′,3′-cGAMP to activate STING in vivo and in vitro, and the in vivo data found out that STING promoted host resistance against PA infection. To investigate the reason why STING played a protective role in PA keratitis, the inflammatory cytokine secretion and bacterial load were measured by using real-time PCR and bacterial plate count, respectively. Our data demonstrated that STING suppressed the production of inflammatory cytokines and enhanced bacterial elimination in murine model of PA keratitis and in PA-infected macrophages. To further investigate the mechanism beneath, the phosphorylation of mitogen-activated protein kinase, the nuclear translocation of nuclear factor-κB (NF-κB) and the bactericidal mechanism were measured by western-blot, immunofluorescence, and real-time PCR, respectively. Our data indicated that STING suppressed inflammatory cytokine expressing via restraining NF-κB activity and enhanced inducible NO synthase expression, an oxygen-dependent bactericidal mechanism. In conclusion, this study demonstrated that STING promoted host resistance against PA keratitis and played a protective role in PA-infected corneal disease, via inhibiting corneal inflammation and enhancing bacterial killing.