CARDS TX对BALB/c小鼠难治性肺炎链球菌肺炎模型的探讨  

Investigation of CARDS TX in a resistant Streptococcus pneumoniae pneumonia model in BALB/c mice

作　　者：李莹[1] 赵开顺 余艳芳 屠春林 LI Ying;ZHAO Kai-shun;YU Yan-fang;TU Chun-lin(Department of Respiratory and Critical Care Medicine,the Affiliated Central Hospital of Jiading District,Shanghai University of Medicine&Health Sciences,Shanghai 201800,China)

机构地区：[1]上海健康医学院附属上海市嘉定区中心医院呼吸与危重症医学科,上海嘉定201800

出　　处：《广东医学》2024年第12期1559-1565,共7页Guangdong Medical Journal

基　　金：上海市嘉定区自然科学研究项目(JDKW-2021-0044)。

摘　　要：目的明确社区获得性呼吸窘迫综合征毒素(community-acquired respiratory distress syndrome toxin,CARDS TX,后文简称CT)在难治性肺炎链球菌小鼠动物模型中的作用。方法采用BamHI酶切位点,EcoRI克隆方法克隆出CT pET28-a+载体,经扩培、表达、提纯等步骤获得CT蛋白,将雌性BALB/c小鼠5~8周龄、体重(20±2)g共60只随机分配为4组,分别为空白对照组(对照组)、单肺炎链球菌(streptococcus pneumoniae,SP)模型组(SP组),肺炎支原体(mycoplasma pneumoniae,MP)+SP共同感染模型组(MP+SP组),单SP+CT处理组(SP+CT组)进行相应肺炎模型建立。在建模的第4天开始阿奇霉素干预治疗,并在第4、5、6天各组分别取5只小鼠,经麻醉后处理小鼠,获取小鼠的支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF),进行SP平板培养;离心小鼠BALF,获取细胞沉淀进行瑞士吉姆萨染色;获取小鼠右肺中叶肺组织,行组织切片HE染色,研磨小鼠左肺组织,获取细胞匀浆上清液,检测并比较所有上清液中γ干扰素(interferon-γ,IFN-γ)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素(interleukin,IL)-6、IL-17、转化生长因子-β(transforming growth factor-β,TGF-β)和IL-10水平。培养所收集的BALF中SP的情况。结果在阿奇霉素治疗结束后,MP+SP组及SP+CT组肺组织的IFN-γ、TNF-α、IL-6、IL-17、TGF-β水平显著高于单SP组及空白对照组,而IL-10水平显著低于单SP组及对照组。肺HE染色和BALF吉姆萨染色中显示,MP+SP组及SP+CT组白细胞浸润明显高于单SP组及对照组。SP培养结果中显示,各组SP菌体的长势及细菌浓度随着阿奇霉素的治疗而逐渐变差,而MP+SP组及SP+CT组的情况则明显优于单SP组。结论在Balb/c小鼠肺炎模型中,CT对共同致炎病原体SP起到一定程度的保护性的作用,在一定程度上延缓了SP对阿奇霉素的应答时间,降低了阿奇霉素对SP的伤害性作用,某种从程度上诱导了SP难治性肺炎的产生�Objective To clarify the role of community-acquired respiratory Distress syndrome toxin(CARDS TX,referred to as CT)in a resistant Streptococcus pneumoniae(SP)mouse model.Methods Using BamHI and EcoRI cloning methods,we constructed the CT pET28-a+vector and expressed and purified the CT protein.Sixty female BALB/c mice aged 5–8 weeks,weighing(20±2)g,were randomly assigned to four groups:a blank control group(control group),a single SP model group(SP group),a Mycoplasma pneumoniae(MP)+SP co-infection group(MP+SP group),and a single SP+CT treatment group(SP+CT group).Azithromycin intervention began on the 4th day post-model establishment.On days 4,5,and 6,five mice from each group were anesthetized to collect bronchoalveolar lavage fluid(BALF)for SP culture,cell sedimentation for Giemsa staining,and lung tissue for HE staining and cytokine analysis[interferon-γ(IFN-γ),tumor necrosis factor-α(TNF-α),interleukin(IL)-6,IL-17,transforming growth factor-β(TGF-β),and IL-10)].Results Post-treatment,the SP+MP group and SP+CT group exhibited significantly higher levels of IFN-γ,TNF-α,IL-6,IL-17,and TGF-βcompared to the SP group and control group,while IL-10 levels were significantly lower.Histological analysis revealed greater leukocyte infiltration in the SP+MP and SP+CT groups.SP growth in culture showed a declining trend post-Azithromycin treatment,with the SP+MP group and SP+CT group faring better than the SP group.Conclusion In the BALB/c mouse pneumonia model,CT provides protective effects against the co-infectious pathogen SP,prolonging SP′s response time to Azithromycin and reducing its detrimental effects,thereby contributing to the development of resistant pneumonia.

关 键 词：社区获得性呼吸窘迫综合征毒素 肺炎链球菌 动物模型 难治性肺炎 

分 类 号：R378.1[医药卫生—病原生物学] R375.2[医药卫生—基础医学]