轻型链球菌缓解铜绿假单胞菌感染小鼠模型的炎症反应及机制的初步探讨  

A preliminary study for the mechanism of Streptococcus mitis in mouse model of Pseudomonas aeruginosa infection

作　　者：侯婷 余加林[1] 艾青[1] 贺雨[1] 肖洒[1] 谭琪[1] 王利[1] 胡坤 李秋平 尹一兵[2] 宋超 Hou Tin;Yu Jialin;Ai Qing;He Yu;Xiao Sa;Tan Qi;Wang Li;Hu Kun;Li Qiuping;Yin Yibing;Song Chao(Department of Neonatology,the Children's Hospital of Chongqing Medical University ,Ministry of Education Key Laboratory of Child Development and Disorders ,Key Laboratory of Pediatrics in Chongqing,Chongqing International Science and Technology Cooperation Base of Child Development and Critical Disorders;Key Laboratory of Laboratory Medical Diagnosis of Education Ministry,Department of Laboratory Medicine,Chongqing Medical University;The Children's Hospital of Zhejiang University School of Medicine)

机构地区：[1]重庆医科大学附属儿童医院新生儿中心儿童发育疾病研究教育部重点实验室儿科学重庆重点实验室儿童发育重大疾病国家国际科技合作基地,重庆410014 [2]重庆医科大学检验医学院临床检验诊断学教育部重点实验室,重庆400014 [3]浙江大学医学院附属儿童医院,杭州310003

出　　处：《重庆医科大学学报》2018年第11期1443-1448,共6页Journal of Chongqing Medical University

基　　金：国家自然科学基金资助项目(编号:81571483);国家临床重点专科建设项目经费资助项目(编号:卫办医政函2011-873);儿童医院临床研究资助项目(编号:[2014]254-lcyj2014-11)

摘　　要：目的:探讨轻型链球菌(Streptococcus mitis,S.mitis)在铜绿假单胞菌(Pseudomonas aeruginosa,PAO1)感染小鼠模型中缓解炎症作用及可能机制。方法:将野生型和TLR2基因缺陷型小鼠随机分为4组,每组20只,通过气管内注入铜绿假单胞菌(PAO1组)、轻型链球菌(S.mitis组)、铜绿假单胞菌+轻型链球菌混合菌液(PAO1+S.mitis组)和生理盐水(PBS组)建立模型,HE染色观察肺组织病理学改变,ELISA检测肺泡灌洗液中炎症因子白细胞介素-6(interleukin-6,IL-6)和肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)的表达,计数肺泡灌洗液细胞总数及细胞分类。结果:野生型小鼠中肺组织病理学显示:PAO1组肺泡间隙增宽明显,有大量炎症细胞浸润,PAO1+S.mitis组炎症较PAO1组稍轻;S.mitis组和PBS组肺组织结构正常,基本未见炎症细胞浸润;肺泡灌洗液中PAO1组IL-6和TNF-α的含量高于PAO1+S.mitis组(P=0.032,P=0.007),S.mitis组和PBS组仅有少量表达;PAO1组BALF细胞总数及中性粒细胞计数均较PAO1+S.mitis组、S.mitis组和PBS组增加(均P<0.05)。TLR2基因缺陷型小鼠中肺组织病理学显示:PAO1组和PAO1+S.mitis组均有肺泡间隙增宽,炎症细胞浸润,肺泡灌洗液中PAO1组和PAO1+S.mitis组IL-6和TNF-α的表达没有统计学差异(P=1.000,P=1.000),S.mitis组和PBS组仅有少量表达;PAO1组和PAO1+S.mitis组支气管肺泡灌洗液细胞总数及中性粒细胞计数没有统计学差异(P=1.000,P=1.000)。结论:轻型链球菌可缓解铜绿假单胞菌炎症反应与TLR2有关。Objective:To investigate the alleviation of inflammatory effects and mechanisms of Streptococcus mitis in infection with Pseudomonas aeruginosa.Methods:Wild-type C57BL/6 and TLR2-/-mice were randomly assigned into 4groups (20in each group).They were treated with an intratracheal instillation of Pseudomonas aeruginosa (PAO1 group),Streptococcus mitis (S.mitis group),Pseudomons aeruginosa and Streptococcus mitis (PAO1+S.mitis group ),and phosphate-buffered saline (PBS group),respectively.The mice were sacrificed at 48h after instillation;the pathological changes in lung tissues were examined with hematoxylin-eosin (HE);the levels of IL-6 and TNF-α in broncho-alveolar lavage fluid (BALF)were evaluated by ELISA ;the total cell counts and neutrophil counts in the BALF were quantified.Results :In wild-type C57BL/6mice,the bronchi and blood vessels in PAO1 group was infiltrated by a large number of inflammatory cells and was complicated with alveolar septum thickening.The pathological changes were milder in PAO1+S.mitis group than in PAO1 group,while there was no significant pathological changes in lung tissue in PBS group and S.mitis group.The levels of IL-6,TNF-α were significantly higher in PAO1 group than that in PAO1+S.mitis group(P=0.032,P=0.007).The total number of BALF cells and neutrophils in PAOI group was the highest among the four groups (P<0.05).In TLR2^-/-mice,alveolar septum thickening and the infiltration of inflammatory cells was observed in PAO1 group and PAO1 +S.mitis group.No statistically significant difference in the expression of IL-6,TNF-α,total number of BALF cells and neutrophils in PAO1 group and PAO1+S.mitis group(all P=1.000)was observed.Conclusion:Streptococcus mitis can alleviate the inflammatory response of Pseudomonas aeruginosa and is related to TLR2.

关 键 词：新生儿 铜绿假单胞菌 轻型链球菌 

分 类 号：R722.1[医药卫生—儿科]