Baculovirus surface display of σC and σB proteins of avian reovirus and immunogenicity of the displayed proteins in a mouse model

• Published in: Vaccine 2008-11, Vol.26 (50), p.6361-6367
• Main Authors: Lin, Yueh H, Lee, Long H, Shih, Wen L, Hu, Yu C, Liu, Hung J
• Format: Article
• Language: English
• Subjects: Allergy and Immunology; Applied microbiology; Avian reovirus; Baculovirus gp64 protein; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Microbiology; Miscellaneous; Universal baculovirus surface display system; Vaccines, antisera, therapeutical immunoglobulins and monoclonal antibodies (general aspects); Virology; σC and σB proteins
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2008.09.008

Abstract Avian reovirus (ARV), an important pathogen in poultry, causes arthritis, chronic respiratory disease, and malabsorption syndrome that cause considerable economic losses to the poultry industry. In present study, we have succeeded in construction of a universal baculovirus surface display system (UBSDS) that can display different foreign proteins on the envelope of baculovirus. Sequences encoding the signal peptide (SS), transmembrane domain (TM), and cytoplasmic domain (CTD) derived from the gp64 protein of baculovirus and histidine tag, respectively were inserted into the pBacCE vector. Four restriction enzyme sites between the histidine tag and gp64 transmembrane domain were established for expression of different foreign proteins. The transmembrane domain and CTD of gp64 in the platform were designed in order to improve stability and quantity of foreign proteins on the envelope of baculovirus. The σC and σB proteins of ARV are known to elicit neutralizing antibodies against ARV. The UBSDS was therefore used to express σC and σB proteins on the envelope of baculovirus. Two recombinant baculoviruses BacSC-σC and BacSC-σB have been successfully constructed. After infection, both His6 -tagged recombinant σC (rσC) and σB (rσB) proteins were displayed on the envelope of recombinant baculoviruses and the recombinant viral proteins were anchored on the plasma membrane of Sf-9 cells, as revealed by immunofluorescence staining (IFS) and confocal microscopy. The antigenicity of rσC and rσB proteins was demonstrated by Western blotting assay. Immunogold electron microscopy demonstrated that both recombinant viruses displayed rσC and rσB proteins on the viral surface. Immunization of BALB/c mice with recombinant viruses, demonstrated that serum from the BacSC-σC and BacSC-σB treated models had significant higher levels of virus neutralization activities than the control groups. This demonstrates that the recombinant baculoviruses BacSC-σC and BacSC-σB can be a potential vaccine against ARV infections.