临床分离革兰阴性菌脂多糖脂质体的制备及免疫保护效应研究

目的制备临床分离的大肠埃希菌,铜绿假单胞菌和肺炎克雷伯菌混合脂多糖脂质体并观察其免疫保护作用。方法采用逆向蒸发法制备细菌LPS脂质体,通过电镜观察其形状,粒径测定仪分析其粒径分布,鲎试验(LAL)测定其活性。用大肠埃希菌TH1菌株、铜绿假单胞菌P7菌株、肺炎克雷伯菌K11菌株混合脂质体免疫小鼠,以脂多糖(LPS)2倍完全致死量(LD100)和100倍半数致死量(LD50)活菌攻击小鼠,观察各组小鼠的存活情况。结果细菌LPS脂质体混悬液常温下呈乳白色,透射电镜下可见LPS脂质体颗粒呈规则的球形,粒径分布均匀,为300～464nm。LAL试验推算包封率为99.0%～99.9%。经TH1、P7、K11混合LPS脂质体免疫的小鼠接受TH1-LPS、P7-LPS、K11-LPS及其活菌攻击后显示具有免疫保护作用,其中TH1-LPS、P7-LPS及活菌攻击组小鼠存活率显著高于对照组(P<0.05)。结论多菌混合脂多糖脂质体对其相应菌种及LPS攻击具有免疫保护作用。

Preparation and immunoprotection of a mixed liposomal lipopolysaccharide from bacteria causing nosocomial infections

Objective To prepare a mixed liposomal lipopolysaccharide(LPS) of Escherichia coli,Pseudomonas aeruginosa,and Klebsiella pneumoniae from clinic isolates and investigate its immunoprotection.Methods A liposomal lipopolysaccharide was prepared by reverse evaporation.Its shape was observed using electron microscopy,its particle size distribution was determined using a particle size analyzer,and its activity was examined using a limulus test.Mice immunized with the mixed liposomal lipopolysaccharide were attack...