Expression and Antigenic Analysis of Recombinant Porcine Circovirus Type 2 Capsid Protein

• Main Authors: Jing-yuan Chen, 陳敬元
• Other Authors: Maw-Sheng Chien
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/05482798762728983858

碩士 === 國立中興大學 === 獸醫病理生物學研究所 === 98 === Porcine circovirus type 2 (PCV2) is thought to be the primary causative agent of porcine circovirus associated disease (PCVAD). Capsid protein of PCV2 is the major viral antigen which can stimulate specific antibody response of infected pigs. In this study, full length of field isolated PCV2 capsid protein gene was cloned to transfer vector to construct recombinant baculovirus, vAcp10-PCV2/Cap. The Sf9 insect cells were infected with recombinant virus to express recombinant protein. The recombinant capsid protein can be recognized by porcine anti-PCV2 specific antibody in immunofluorescence assay and Western blot analysis indicating the correct immunogenicity of recombinant protein. To evaluate the immunogenicity and protection efficiency, the purified recombinant protein was inoculated in SPF piglets. The recombinant protein was also attempt to be used as ELISA coating antigen, and the result showed significant difference between porcine anti-PCV2 specific antibody and SPF pig serum samples. This study also evaluated the immune-efficiency of eukaryotic expression vector which contains full length of PCV2 capsid gene in mice model. The specific antibody titers from immunized mice increased as tested by ELISA after the third vaccination. Moreover, the number of antibody secretion cells (ASC) isolated from the spleen of the immunized mice also increased when cells were stimulated with recombinant PCV2 capsid protein expressed by baculovirus and Sf9 cells in vitro and detected by ELISPOT analysis. These results proved the subunit PCV2 DNA vaccine can raise the specific antibody response of immunized mice. Overall, the PCV2 capsid protein expressed by baculovirus expression system and the recombinant protein in this study not only can be applied as diagnostic reagent but the immunogenicity of recombinant protein will also be analyzed in pig animal model. It was proven in the mice model the possibility of PCV2 DNA vaccine. In the future, the recombinant protein may be applied with DNA vaccine in pig animal model to investigate the efficiency of subunit vaccine.