Display Of Classical Swine Fever Virus E0and E2on The Surface Of BmNPV And Their Immunogenicity Study

Classical swine fever (CSF) is a serious threat to the current pig industry, whichis caused solely by classical swine fever virus (CSFV). So it is necessary to developnew vaccinations against CSF. While the envelope glycoproteins E0and E2, as theviral main structural proteins and the protective antigen against CSFV, can stimulatethe body to generate neutralizing antibodies, and play the key role in the spreading ofthe virus. Thus, the envelope glycoproteins E0and E2may be as antigen targets forpreparing new vaccine.BmNPV Surface Display System can display foreign proteins by inserting targetgene in frame into baculovirus gp64on the surface of virons. Then the virus can beused to immune animals to produce antibodies, avoiding traditional tedious proteinpurification procedure. Furthermore, using silkworm pupae as bioreactor is suitablefor scaleup production and reduces the cost of preparing vaccines.In our research, both the E0and E2genes were cloned to express in E.coli byfused with BmNPV polh. The expression product was purified and used to immunizemale New Zealand rabbits for polyclonal antibodies. Meanwhile, these two geneswere cloned into pFastBac1-SP-TM, respectively, and made recombinant baculovirusBmNPV-E0and BmNPV-E2with a BmBac–to-Bac system. The virons ofBamNPV-E0and BamNPV-E2were prepared and used directly to immunize Balb/cmice. The titers of the resulting anti-serums got up to1:800for BmNPV-E0and1:1600for BmNPV-E2, respectively, indicating that both BmNPV-E0andBmNPV-E2could stimulate to produce protection antibody.These experiments not only proved the availability of using BmNPV surfacedisplay system to express CSFV protein E0and E2on the surface of BmNPV, butalso laid a good foundation to produce new vaccines against CSFV.