鲍曼不动杆菌外膜蛋白疫苗的制备及其保护作用评价

Preparation and protective effect evaluation of outer membrane protein from Acinetobacter baumannii

目的鲍曼不动杆菌(Acinetobacter baumannii,Ab)的感染及广泛耐药是临床防治的一大难题,国际上Ab疫苗的研制尚未成功,本研究旨在开发新型Ab候选疫苗预防其感染。方法本研究使用脱氧胆酸钠法制备鲍曼不动杆菌外膜蛋白(out membrane protein,OMP)疫苗,命名为Ab dOMP疫苗,并通过透射电镜(TEM)、十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDSPAGE)对其进行表征,构建Ab感染致死模型评价疫苗的保护效果,并作免疫应答机制分析。结果Ab dOMP疫苗滴鼻免疫的保护率为71.43%(P<0.05),显著高于肌注组(保护率为28.57%)。疫苗免疫可诱导显著的血清特异性IgG应答,且与肌注免疫相比,滴鼻免疫还可以诱导高水平的特异性sIgA。Ab dOMP疫苗可以显著刺激BMDCs表面成熟标志CD40、CD80和CD86表达上调,以及促进细胞因子TNF-α、IL-12p70、IL-10、IL-6和IL-1β的分泌。结论Ab dOMP疫苗对鲍曼不动杆菌感染具有良好的保护作用,且滴鼻免疫的保护效果优于肌注免疫。

Acinetobacter baumannii(Ab)is a threat to clinical treatment,and there is no successful vaccine of Ab,so we aim to develop a novel Acinetobacter baumannii vaccine candidate to prevent Ab infection.A method of sodium deoxycholate was used to prepared the Acinetobacter baumannii outer membrane proteins(OMP),designated Ab dOMP.The morphology and composition of Ab dOMP were characterized by transmission electron microscope(TEM)and sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE).The protection effect of Ab dOMP was evaluated,and the immune response mechanisms were analyzed.Data showed that the protective rate of intranasal immunization of Ab dOMP was 71.43%,which was significantly higher than that of intramuscular immunization(protective rate:28.57%).Both routes of Ab dOMP immunization induced higher level of serum IgG,while intranasal immunization elevated specific sIgA response additionally.Furthermore,Ab dOMP could significantly increase the expression of CD80 and CD86,and up-regulate the cytokines of TNF-α,IL-12p70,IL10,IL-6 and IL-1β.In conclusion,Ab dOMP vaccine provide significant protective effect against Acinetobacter baumannii infection,and the protective effect of intranasal immunization is better than intramuscular immunization.