Expression Of VP1 And VP2 Genes Of Chicken Anemia Virus And On Immunogenicity

Chicken infectious anemia(CIA), also known as blue wing disease, hemorrhagic syndrome and anemia dermatitis syndrome, caused by a member of the Circoviridae--Chicken infectious anemia virus(CIAV), is an immunosuppressive disease characterized by lymphoid depletion in lymphatic tissues and aplasia of the bone marrow in young chickens. The titer of CIAV in MSB1 cells and chicken embryo is low, which made the production cost of CIA inactivated vaccine great and hard to applicate in the field. Live vaccine is also hard to promote for security risk. In recent years, research of genetic engineering vaccine has become hot spot in CIAV research.To explore the possibility of manufacturing CIAV subunit vaccines, three groups of recombinant vectors: p Fast Bac HTA-VP1 and p Fast Bac HTA-VP2, p Fast Bac HTA-VP1-IRES-VP2, p Fast Bac Dual-VP1-VP2 were constructed to express VP1 and VP2 genes of CIAV in Bac-to-Bac baculovirus expression system. Recombinant bacmids were gained by transforming in DH10 Bac cells. Finally, by transforming the Sf21 cells with the recombinant bacmids, recombinant baculoviruses(v Bac-VP1, v Bac-VP2, v Bac-VP1-IRES-VP2, v Bac-VP1-VP2) containing VP1 and VP2 genes have been obtained. Three groups of recombinant baculoviruses infect the Sf21 cells in this way: v Bac-VP1 and v Bac-VP2 infect the Sf21 cells together; v Bac-VP1-IRES-VP2 and v Bac-VP1-VP2 infect the Sf21 cells alone. It’s proved by SDS-PAGE and Western-blot that VP1 and VP2 genes were expressed in Sf21 cells successfully. SPF chickens vaccinated with inactivated oil-emulsion vaccine containing recombinant protein generated specific antibody. These results showed the recombinant proteins are immunogenic.Chickens vaccinated with protein expressed by v Bac-VP1, v Bac-VP2 and protein expressed by v Bac-VP1-IRES-VP2 showed similar immunogenicity, while chickens vaccinated with protein expressed by v Bac-VP1-VP2 showed the best immunogenicity among them. The recombinant protein expression of CIAV lays the foundation for subunit vaccine of CIAV and has a good prospect in the future.