Influence Of Immunogenicity Of Recombinant Porcine IL-15 Against The PPV VP2-PCV2 ORF2 Nucleic Acid Vaccine

In this experiment, the amplified ORF2 gene was Connected to the N terminus of VP2(PPV strain SC-1) gene, and then clone it into the eukaryotic expression vector pCI-neo to construct the eukaryotic expression plasmids pCI-ORF2-VP2. On this basis, construct the recombinant plasmids pCI-IL15-ORF2-VP2 by cloning the porcine IL-15 gene into the pCI-ORF2-VP2. Transfect it into PK15 cells by the Lipofectamine and observe the fusion expression of green fluorescent protein. Immunise the healthy mice with recombinant plasmids pCI-IL15-ORF2-VP2 and set plasmids pCI-ORF2-VP2,Porcine Parvovirus vaccine,Porcine Circovirus subunit vaccine,plasmids PCI-neo as control groups. The spleen lymphocyte proliferation activity was detected by MTT method, the variation of CD4+,CD8+ T lymphocyte were detected by Flow cytometry. The antibody of PPV and PCV2 were measured by ELISA. Extracting the genome from solid organ after 35d to detect the security of the nucleic acid vaccine by PCR amplification.The results showed that the recombinant plasmids was successfully constructed and can be observed a large number of green fluorescent in the PK15 cells. It indicates that the recombinant plasmids can be normally expressed.The ratio of CD4+,CD8+ in the peripheral blood T lymphocyte and the activity of spleen cells raised in a certain degree. The PPV,PCV2 antibody levels of the pCI-IL15-ORF2-VP2 were higher than the pCI-ORF2-VP2 and other Control groups. No VP2,ORF2 gene was amplified by PCR from the extracted genome from solid organ of mice showed that the nucleic acid vaccine was secure.Summary, whether the level of cellular immunity or the level of specific antibody have greatly enhanced by restructuring porcine IL-15. Therefore,cloning IL-15 into the eukaryotic expression plasmids was a effective way to enhance the Immunogenicity of the nucleic acid vaccine.The results provide a reference to use the IL-15 as well as any other other cytokines as the nucleic acid vaccine adjuvant,it also lay the foundation for researching the new and efficient vaccine of PPV and PCV2.