口蹄疫病毒3D蛋白对DNA疫苗免疫效果的影响

将携带O型FMDVChina 99株P1 2A、部分 2B及 3C蛋白酶编码基因的真核表达质粒与在毕赤酵母中表达的纯化FMDVChina 99株 3D蛋白同时经肌肉注射方法接种豚鼠。以MTT法检测豚鼠脾淋巴细胞经植物血凝素 (PHA)刺激后的增殖活性 ,以间接ELISA方法检测血清FMDV特异抗体变化 ,并以微量中和试验检测中和抗体水平。结果表明 ,FMDDNA疫苗与 3D蛋白共同免疫豚鼠后 ,抗体水平没有明显提高 ,攻毒后的保护率为 2 5 %。

Immune response of DNA vaccine against foot-and-mouth disease virus in cavians enhanced by 3D protein expressed in the Pichia pastoris secreted expression system

In order to evaluate the enhanced immune response of the foot-and-mouth disease virus (FMDV) DNA vaccine, which was designed to produce viral capsids lacking infectious viral nucleic acid, the gene P12X3C including full length P1, 2A, 3C and a part of 2B was constructed. FMDV 3D protein, which was expressed in the Pichia pastoris secreted expression system and was purified, was injected with pcDNA3.1/P12X3C. The anti-FMDV antibodies were detected by indirect ELISA. The T lymphocyte proliferation response was tested by MTT assay. The neutralization antibodies titers were analyzed by micro-neutralization assay .The results indicated that anti-FMDV antibodies were elicited and increased by plasmid DNA in the second week after vaccination, that the neutralization antibodies were induced with high level and that the T lymphocyte proliferation response was enhanced after vaccination. In the challenge test, all cavians immunized with pcDNA3.1/P12X3Cwere fully protected againstFMDV challenge, but the result obtained from the group injected with 3D protein together plasmid pcDNA3.1/P12X3C wasnot satisfying. In conclusion, the results encouraged further work towards the development of DNA vaccines against FMDVand providedthe basis of research for DNA vaccines.