MPT63核酸疫苗的制备及其免疫原性

扩增结核分枝杆菌分泌蛋白MPT63编码序列 ,克隆于真核表达载体pJW 4 30 3中 .转染COS 7细胞 ,用Western印迹检测表明该基因在细胞内得到正确表达 .用该质粒连续免疫C5 7BL 6小鼠 3次后 ,用纯化的重组蛋白MPT63检测小鼠血清中的抗体 ,发现抗体滴度达到 10 5,免疫动物中γ干扰素的含量达到 2 5 8± 0 2U ml ,为空载体DNA免疫对照组的 2 0倍以上 ,说明MPT63核酸疫苗在实验动物体内引起了较强的免疫应答

Preparation of MPT63 DNA Vaccine and Its Immunogenicity

Nucleic acid sequence encoding MPT63 protein was amplified by PCR and cloned into the eukaryotic expression vector pJW4303. The recombinant plasmid was expressed in COS-7 cells, and then confirmed by Western blotting. This MPT63 DNA vaccine was inoculated intramuscularly into C57BL/6 mice three times at 3 weeks interval. After vaccination, the specific antibody titers and the level of specific γ-interferon were determined using purified MPT63 expressed in prokaryotic cells. The antibody titers increased sharply to greater than 10 5 after the second vaccination, and the splenocytes from mice produced 25.8±0.2 unit/ml γ-interferon after the third vaccination, which was 20 times higher than that of mice injected with the empty vector pJW4303. It could be concluded that MPT63 DNA vaccine induced strong immune responses in experimental mice and could be used as a candidate for immunotherapy of tuberculosis.