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目的 :构建表达肠毒素性大肠杆菌菌毛抗原基因CS6和霍乱毒素B亚基 (CTB)基因的细菌性腹泻基因工程多价疫苗。方法 :以基因工程减毒的人伤寒沙门菌为抗原载体 ,利用基于asd基因功能互补的宿主染色体_质粒平衡致死表达系统 ,实现了在没有抗生素选择压力的条件下 ,CS6和CTB在人伤寒沙门菌中的稳定表达。结果与结论 :检测结果表明 ,CS6和CTB的表达虽对宿主菌的生长有一定影响 ,但经过一段时间的培养 ,重组菌株仍可达到高密度生长。动物免疫结果显示 ,重组菌株在家兔体内均可诱生相应抗体 ,但从诱生的抗体效价、抗体持续时间方面评价 ,单独表达CS6与CTB的重组菌株的免疫学效果均好于两者共表达的重组菌株 ,提示在以后的疫苗研究实践中 ,可以考虑将分别表达CS6与CTB的重组菌株按一定比例混合 ,组成联合疫苗 ,用于细菌性腹泻的免疫预防。本研究结果对于细菌性腹泻基因工程多价疫苗的构建有指导意义。
Objective: To construct a bacterial diarrhea gene engineering multivalent vaccine expressing enterotoxigenic Escherichia coli pilus antigen gene CS6 and cholera toxin B subunit (CTB) gene. Methods: The genetically engineered human Salmonella typhimurium was used as the antigen carrier. Based on the host chromosome-plasmid lethal expression system based on the complementation of asd gene function, we found that in the absence of antibiotic selection pressure, Stable expression in bacteria. RESULTS AND CONCLUSION: The results showed that although the expression of CS6 and CTB had an impact on the growth of host bacteria, the recombinant strains could still achieve high density growth after a period of cultivation. The results of animal immunization showed that the recombinant strains could induce the corresponding antibodies in rabbits. However, the immunogenicity of the recombinant strains expressing CS6 and CTB alone was better than both of the induced antibody titers and the antibody durations Recombinant strains co-expressed, suggesting that in the future vaccine research practice, consider the expression of CS6 and CTB recombinant strains were mixed in a certain ratio, the composition of the combination vaccine for bacterial diarrhea immunoprophylaxis. The results of this study for the construction of bacterial diarrhea genetic engineering polyvalent vaccine has guiding significance.