摘要
对构建的重组质粒ｐＸＳＴ１（含有耐热性肠毒素ＳＴ１和ＬａｃＺ基因）进行核苷酸序列分析的结果表明，该质粒中含有２个正向串联在一起的ＳＴ１基因，且融合在ＬａｃＺ基因的上游，具有正确的阅读框架。免疫学试验结果表明，构建的ＤＨ５α（ｐＸＳＴ１）重组菌株安全无毒。该重组菌株表达的ＳＴ１融合蛋白能够诱发ＢＡＬＢ／ｃ鼠产生抗体，且抗体能中和天然肠毒素ＳＴ１活性，具有较好的免疫保护作用。由此表明。
The 5′terminus of the gene that codes for the heat stable enterotoxin Ⅰ of Escherichia coli (ST 1) was genetically fused to the 3′terminus of the LacZ gene that codes for the β galactosidase. We constructed the recombinant plasmid pXST 1 and studied it in detail by DNA sequencing. The results showed that the pXST 1 carried two ST 1 genes, had positive reading frame, and could express the ST 1 β galactosidase fusion protein. More importantly, the fusion protein was nontoxic and immunogenic. BALB/c mice immunized with crude preparation containing the fusion protein produced antibodies that was able to recognize ST 1 enterotoxin in vitro. Significantly, these antibodies were able to neutralize the biological activity of native ST 1 enterotoxin in the suckling mouse assay. Hence the recombinant strain DH5α(pXT 1) could be used as candidate of vaccine strain.
出处
《中国兽医学报》
CAS
CSCD
1996年第4期327-332,共6页
Chinese Journal of Veterinary Science
基金
军队医药卫生科研基金
关键词
大肠杆菌耐热性肠毒素Ⅰ
融合蛋白
免疫原性
Escherichia coli
heat stable enterotoxin Ⅰ
fusion protein
immunogenicity * Biological Engineering Institute, Academy of Military Medicine
