呼吸道迟缓爱德华菌不同组分对肺部炎症作用的对比分析

Comparative study of effect of different components of Edwardsiella tarda on pulmonary inflammation

目的探讨呼吸道迟缓爱德华菌不同组分对肺部损伤的影响及其促炎作用。方法应用迟缓爱德华菌灭活菌体、裂解物和代谢物滴鼻构建小鼠急性肺损伤模型和体外细胞实验,细胞分类计数分析支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)炎性细胞情况;酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测BALF和细胞培养上清中促炎细胞因子的表达情况;组织化学法分析肺组织中嗜酸性粒细胞和白细胞介素(interleukin,IL)33阳性细胞的浸润情况。结果迟缓爱德华菌裂解物和代谢物滴鼻组可明显诱导小鼠气道中性粒细胞和巨噬细胞增加以及促炎细胞因子IL-1β、IL-6和肿瘤坏死因子α(tumor necrosis factorα,TNF-α)分泌增多的炎症反应(P<0.05);灭活菌体可诱导肺组织嗜酸性粒细胞和IL-33+细胞的浸润增加(P<0.05)。体外实验表明迟缓爱德华菌不同成分可诱导人和小鼠肺泡上皮细胞和巨噬细胞不同程度地产生促炎细胞因子(P<0.05)。结论呼吸道迟缓爱德华菌可引起肺部炎症反应,促炎细胞因子可能主要通过诱导肺泡上皮细胞和巨噬细胞产生。

Objective To explore the effects of different components of Edwardsiella tarda on pulmonary inflammatory responses and to clarify the potential role of Edwardsiella tarda in progression of chronic obstructive pulmonary disease(COPD),which might provide a novel theoretical basis for the pathogenesis of COPD.Methods In vivo,mice were given different components derived from Edwardsiella tarda(inactivated bodies,bacterial lysates and supernatant of cultured bacteria)intranasally to establish mice models of acute lung injury.Inflammatory cells in bronchoalveolar lavage fluid(BALF)were analyzed by cell differential counting on stained smears;enzyme-linked immunosorbent assay(ELISA)was used to measure the concentrations of proinflammatory cytokines in BALF;Histochemical and immunohistochemical staining were individually employed to detect eosinophils and IL-33+cells in lung tissue.In vitro,different components derived from Edwardsiella tarda were used to stimulate pulmonary epithelial cells and macrophages,and concentrations of proinflammatory cytokines in the cell culture supernatant were also measured by ELISA.Results The bacterial lysates and metabolites of Edwardsiella tarda significantly increased the number of neutrophils and macrophages and the levels of the pro-inflammatory cytokines IL-1β,IL-6 and tumor necrosis factorα(TNF-α)in BALF;inactivated bacteria induced more eosinophils and IL-33+cells infiltration in lung tissue.The different components of Edwardsiella tarda also stimulated production of proinflammatory cytokines by human and murine pulmonary epithelial cells and macrophages.Conclusion Edwardsiella tarda can cause pulmonary inflammatory response,possibly through inducing inflammatory cytokines by epithelial cells and macrophages.