Baculovirus surface display of E rns envelope glycoprotein of classical swine fever virus

Abstract

Classical swine fever virus (CSFV) causes significant losses in the pig industry in many countries. E rns is an envelope glycoprotein of CSFV which is known to induce virus-neutralizing antibodies and protective immunity in the natural host. In this study, one recombinant baculoviruses BacSC-E rns expressing histidine-tagged E rns with the transmembrane domain (TM) and cytoplasmic domain (CTD) derived from baculovirus envelope protein gp64 was constructed and its immunizing efficacy was evaluated in a mouse model. After infection, E rns was expressed and anchored on the plasma membrane of Sf-9 cells, as demonstrated by Western-blot and confocal microscopy. Immunogold electron microscopy demonstrated that the E rns glycoprotein was successfully displayed on the baculoviral envelope. Vaccine tests in animals showed that BacSC-E rns elicited significantly higher E rns antibody titers in the immunized mouse models than the control group. This demonstrates that the BacSC-E rns vaccine can be used potentially against CSFV infections. This is the first report demonstrating the potential of E rns-pseudotyped baculovirus as a CSFV vaccine.