汉滩病毒84Fli株DNA疫苗诱导小鼠免疫应答的初步研究

Initial Study on the Efficacy of DNA Vaccines against Hantaan Virus 84Fli Strain in C57BL/6 Mice

为了加强我国病毒性出血热的防治,本研究将汉滩病毒84Fli株核蛋白S和糖蛋白M编码片段分别克隆至pcDNA3.0载体,构建了pcDNA3/84S和pcDNA3/84M重组质粒,等量混合采用肌肉注射途径免疫C57BL/6小鼠,免疫3次,每次间隔2周,同时与双价出血热病毒灭活疫苗进行对比。ELISA及免疫荧光(IFA)分别检测小鼠血清中汉滩病毒核蛋白及糖蛋白特异性抗体,流式细胞仪和ELISPOT方法分析小鼠免疫后的细胞免疫水平。微量中和试验检测小鼠血清抗体的的中和活性。结果显示,DNA疫苗免疫组C57BL/6小鼠在初次免疫2周后即能检测到汉滩病毒核蛋白与糖蛋白的特异性抗体,与灭活疫苗组相比,重组质粒诱导的抗体滴度高,产生时间早,产生的抗体具有中和活性;同时可诱导产生特异性细胞免疫应答。研究表明,汉滩病毒pcDNA3/84S和pcDNA3/84M重组质粒能有效刺激小鼠产生特异性体液免疫和细胞免疫应答。

C57BL/6 mice were immunized intramuscularly every 2 weeks for 3 times with pcDNA3.0-backbone recombinant plasmids of Hantaan virus 84Fli that encoded the NP and GP proteins, and contrasted with bivalent inactivated EHF vaccine. ELISA and indirect immunofluorescence assays were used to detect the serum antibody titers of immunized mice. FACS and ELISPOT assays were applied to detect the CTL activities induced in mice by different vaccines. Titers of neutralization antibody were analyzed with neutralization test. Results showed that both recombinant plasmids and inactivated vaccine could induce Hantaan virus specific humoral responses, moreover the antibody titer induced by DNA vaccine was significantly higher than that by inactivated vaccine. In short, there were significant cellular immune responses in DNA vaccination group.