PPV VP2和PCV2 ORF2重组病毒样颗粒的获得及其免疫原性研究

Recombinant virus-like particles obtained with PPV VP2 and PCV2 ORF2 and their immunogenicity

将PCV2 ORF2基因插入PPV VP2基因HindⅢ酶切位点(即PPV VLPs的N端1/3处)获得重组基因VP2.ORF2,并将其克隆到真核表达载体pEGFP-C1中得到重组质粒pEGFP-VP2.ORF2,经转染及电镜观察表明成功获得VP2.ORF2重组病毒样颗粒。重组病毒样颗粒经超速离心纯化后免疫小鼠,同时设立PPV普通疫苗、PCV2弱毒株及空白对照组,并在不同时期检测小鼠CD_3^+、CD_4^+、CD_8^+T淋巴细胞动态变化情况及PPV和PCV2抗体水平。结果显示:VP2.ORF2重组病毒样颗粒免疫小鼠后能诱导较高水平的细胞免疫和高于同等条件普通疫苗和弱毒株的体液免疫水平。此研究结果为进一步探索VP2.ORF2重组病毒样颗粒的形成机制提供了依据,也为PPV-PCV2二联疫苗的研发打下了基础。

The recombinant gene VP2.0RF2 obtained by inserting PCV2 ORF2 into the Hin d Ⅲ position (located at 1/3 N terminus of PPV VLPs)of PPV VP2 gene was cloned into eukaryotic expression vector pEGFP-C1, and the recombinant plasmids of pEGFP-VP2. ORF2 were constructed. The electronmicroscope observation and the transfection showed that the recombinant virus-like particles were obtained successfully. The particles were then purified by ultracentrifugation. The healthy mice were immunized with the recombinant virus-like particles, also, the porcine parvovirus vaccine, attenuated porcine circovirus and 0.9% NaCl were taken as the controls respectively, and the dynamic variation of blood T lymphocytes and the antibody variation of PPV and PCV2 in serum were measured at different times after immunizing. The results showed that the recombinant virus-like particles can induce cell mediated immunity and higher humoral immunity than PPV vaccine and attenuated porcine circovirus. It laid a foundation for further study on the morphogenesis of recombinant virus-like particles and further research on bigeminy vaccine of PPV and PCV2.