Monoclonal Antibody Preparation Of Classical Swine Fever Virus E2 Protein And Preliminary Study On E2 Gene Minicircle DNA Vectors

Classical swine fever(CSF)is a highly contagious viral disease caused by classical swine fever virus(CSFV),it can cause great loss to the pig industry.To understand the epidemic situation of classical swine fever virus in Shandong province,we detected antigens and antibodies of classical swine fever virus in Shandong province from 2016 to 2017 in this paper.In 2016,2297 antigenic samples were detected,the positive sample size were 230 and the positive rate was 10.01%.And 783 antigenic samples were detected,67 positive sample were found and the positive rate was 8.55%in 2017.For antibodies detected of classical swine fever virus,9713 samples were collected,79.73%all of them had antibody in 2016;the number of simple in 2017 were 6887,and the positive percentage were 84.78.So we know,the antigen infection rate of CFS showed a declining trend in 2017 to 2016;but the antibody positive rate rised.8 strains of classical swine fever virus was isolated,and them E2 gene were analysised.The results show that all of them are mainly distributed in the 2.Id gene subgroup,it may be a epidemic strains gene subgroup.And we analysised the whole genome of classical swine fever virus SDWF 2016.Monoclonal antibody has the advantages of high specificity and sensitivity.It can be used to distinguish between CSFV and BVDV infection.In this experiment,the E2 gene plasmid of prokaryotic expression protein to immune mouse was constructed based on SDWF 2016.The monoclonal antibody diluted 800 times for indirect immunofluorescence assay,can identify CSFV infection very well.It can be used for further research.DNA vaccines were a plasmid that have the component to copy and regulating eukaryotic expression can encoding exogenous antigen gene in animals,induce specific immune responsethen provide protection.But a potential danger of it is integrating and converting bacteria DNA into the host chromosome.Minicircle DNA Vectors can shorten the length of bacterial vectors fragments by the site specific recombinant enzymes,reduceing the potential danger.CSFV E2 gene absence of TMR,can make antigens more easily secreted into cells and strengthen the humoral immune response.In our experiment,the DNA vaccine of the SDWF 2016 E2 delete TMR gene was constructed by using the Minicircle DNA Vectors.We found that antibody level is positively of the mice immunized with pMC-E2d-MC after 5 weeks.The antigen specific percentage of proliferating CD8+ T cell,IFN-y-producing lymphocytes,IL-4-producing lymphocytes were10.67%,1.98%,0.722%,respectively,analyzed by Flow cytometry.The result show the plasmid using the Minicircle DNA Vectors can induce low level humoral immune response and cellular immune response.Our study provides a new idea for the development of new vaccines.