摘要
为预防细菌性痢疾的爆发和流行,构建志贺氏福氏2a减毒活疫苗。选用中国痢疾杆菌主要流行株sf301为受体菌,通过基因重组交换技术,突变细菌DsbA和virG基因,并以Serney试验和HeLa细胞侵袭实验鉴定突变菌株sf301:△virG:DsbA33G毒力和侵袭力,采用豚鼠结膜囊接种免疫动物,检测突变菌株免疫原性,了解候选疫苗对免疫动物的保护能力。与野生亲本比较sf301:△virG:DsbA33G已完全丧失毒力,但保留了一定的侵袭力。与未接受免疫的对照组相比,通过粘膜途径免疫的豚鼠,无论是单次免疫,还是双次免疫策略都可以诱发血清和胃肠道粘膜部位产生特异性抗sf301LPSIgG和IgA;面部、胃肠道引流淋巴结和脾脏中IgG和IgA抗体分泌细胞(Antibody secretcells ASCs)数目显著性增高;两种免疫方案都可给免疫动物提供100%抵抗野生亲本毒株攻击的能力。初步动物实验结果提示构建的福氏2a活疫苗sf301:△virG:DsbA33G是一种潜在的候选痢疾疫苗。
Construction and characterization of a live attenuated Shigella flexneria 2a sf301 vaccine strain to prevent the endemic of shigellosis. Using Chinese majority epidemic ShigeUa flexneri 2a serotype sf301 as the target, p△virG, a deletion derivation of the virG gene in the SacB suicide vector pCVD442 and pDsbA33G, an mutant of a disulfide bond catalyst DsbA, replaced its 33 amiano acid Cystine by Glycerin in pCVD442,were used to generate a attenuated mutant strain sf301：△virG： DsbA33G. Its virulence was evaluated by Sereny test, the invasive ability was detected by HeLa cell invasive assay, immunogenicity was detected by immunized Guinea pigs through inoculated guinea pigs＇ conjunctive sac. Sereny test was negative and HeLa invasive assay showed sf301 ： △virG ： DsbA33 G retained partial invasive ability. In contrast to control group, sf301 ： △virG ： DsbA33 G could induced significantly high antibody levels of IgA and IgG against sf301 LPS in animal＇s mucosal lavage fluids and sera in both primary immunization protocol and boosting protocol. The numbers of ASCs in local draining lymph nodes and spleens were significantly higher than control group. The immune response to sf301 ： △ virG ： DsbA33 G could provide completely protection from the challenge of wild type sf301, sf301 ： A virG.DsbA33 G is a safe and effective oral candidate vaccine to prevent the infection of Shigella strains.
出处
《微生物学报》
CAS
CSCD
北大核心
2005年第5期748-752,共5页
Acta Microbiologica Sinica
基金
国家"863计划"(2001AA215221)
西安交通大学第一医院院基金(2001.YK.21)~~
