【摘要】 目的:探讨人中性粒细胞α-防御素对小鼠感染肺炎克雷伯杆菌肺炎模型动物的保护作用。方法:①用克雷伯肺炎杆菌临床分离株K4与不同浓度α-防御素在37℃孵育两小时,平板培养菌落计数法计数活细菌数。②用K4和α-防御素混合经肺部感染昆明种小鼠,观察小鼠生存率。结果:①K4与α-防御素共孵育的菌落数和PBS对照组菌落数比较没有显著性差异。②肺部注入肺炎克雷伯杆菌混合α-防御素组小鼠的死亡率低于单纯注入肺炎克雷伯杆菌的对照组,且生存时间延长(P<0.05)。结论:α-防御素可以保护小鼠抵抗细菌性肺炎,保护机制可能不是α-防御素的直接杀菌,而可能是通过增强上皮细胞天然免疫功能。更多还原

【Abstract】 Objective:To investigate the protective effect of human neutrophil α-defensins on a murine model of respiratory infections induced by Klebsiella pneumoniae.Methods:①To assay the in vitro antibacterial activity of α-defensins,Klebsiella pneumoniae clinical isolate K4 is incubated with human neutrophil α-defensin at different concentrations for 2 hours.Bacteria were quantified by plating appropriate dilutions on Luria-Bertani agar plates.②.In survival studies,mice are intratracheally challenged with Klebsiella pneumoniae clinical isolate K4 in the presence or absence of α-defensins,and the survival numbers of the animals were observed daily.Results: ①In the presence of physiological saline,human neutrophil α-defensin showed no antibacterial activities against Klebsiella pneumoniae clinical isolate K4.②.The mortality of the mice challenged with Klebsiella pneumoniae K4 plus α-defensins is lower than the control mice challenged only with Klebsiella pneumoniae K4(P<0.05).Conclusion: Human neutrophil α-defensins could protect mice against Klebsiella pneumoniae respiratory infections.The direct microbicidal activities of α-defensins do not contribute to the protective effect.The mechanisms of the protection may be correlated with the enhancement of the innate defense of airway epithelial cells by α-defensins.更多还原