弓形虫多表位DNA疫苗的构建及其免疫保护作用

目的:构建弓形虫多表位DNA疫苗并研究其免疫保护效果.方法:将编码含弓形虫多个T、B细胞表位的6段弓形虫多肽基因,以5个甘氨酸编码基因相间隔相连接,克隆入真核表达质粒pcDNA3.1( )中,构建成多表位弓形虫DNA疫苗.免疫BALB/c小鼠,测定其诱导的特异性抗体水平及T淋巴细胞增殖状况,同时进行弓形虫攻击感染保护实验.结果:成功构建了包含多个弓形虫表位的真核表达质粒pcDNA3.1/T-ME,以其作为DNA疫苗免疫小鼠,可诱导机体产生弓形虫特异性的体液及细胞免疫应答,产生有效的抗弓形虫保护性免疫应答.结论:构建的弓形虫多表位DNA疫苗能诱导机体产生有效的保护性免疫应答,在控制弓形虫感染上具有可行性.

Construction of multi-epitope DNA vaccine for Toxoplasma gondii and the study on protective immunity response in mice

AIM: To construct multi-epitope DNA vaccine for Toxoplasma gondii and study its protective immunity response. METHODS: The gene encoding six polypeptides of T. gondii, which consists of plenty of T and B epitopes, was cloned into the eucaryotic expression vector pcDNA3.1(+). BALB/c mice were vaccinated by this multi-epitope based DNA vaccine (intramuscular needle injection). The specific antibody and T cell proliferation were determined. Meanwhile, the DNA-vaccinated mice were challenged with a lethal dose of T. gondii tachyzoites for further observation. RESULTS: The eukaryotic expression plasmid (pcDNA3.1/T-ME) encoding plenty of T. gondii epitopes was constructed successfully. pcDNA3.1/T-ME immunization induced T. gondii specific humoral and cellular immunity in mice. The mice immunized with pcDNA3.1/T-ME survived significantly longer than the mice in control after challenged by T. gondii RH strain infection. CONCLUSION: The multi-epitope DNA vaccine can induce the protective immunity against T. gondii infection effectively in vivo, which is a potential strategy to control T. gondii infection.