基因工程龋齿疫苗菌株的构建

Study on a Recombinant Dental Caries Vaccine Strain

采用PCR技术，扩增出两端分别增添了EcoR1和BamH1酶切位点的变链菌GTF基因，将其与高效表达的质粒PBV220载体连接后，克隆到大肠杆菌中，成功地构建出一株高效表达GTF基因的菌株。该菌株培养方法简便，GTF抗原表达量高，稳定性好，抗原主要存在于细胞内部，无包涵体形成，用所提的GTF抗原免疫家兔具有明显的免疫原性．是制备龋齿疫苗较为理想的工程菌株。

The glucosyltransferase (GTF) gene of Streptococcus mutants was amplified by PCR. After 2 restriction enzyme sites (EcoR1 and BamH1 ) were added to its 2 terminals respectively, the GTF gene was connected with PBV220 vector and cloned into a strain E. coli which could highly express GTFf The strain showed good stability, and the Culture method of it was simple. The GTF antigen expressed by the strain was mainly present within the cells, and no inclusion body was formed. Animal test proved that the purified GTF antigen from the strain showed good immunogenicity. It indlcated that this genetic engineered strain could be used for the preparation of dental caries vaccine.