Uses of recombinant ORF2 protein of PCV2 as antigen for ELISA to detect specific antibodies against PCV2 in swine sera

Abstract

Results of recent studies indicated that the ORF2- encoded protein of porcine circovirus type 2 carried the major immunogen. Additionally, the recombinant ORF2 protein reacted strongly with swine serum after pig was infected with PCV2. It indicated a possibility to use the recombinantORF2 protein in the diagnostic assays such as ELISA. In this study, we have employed the baculovirus expression system to produce recombinant ORF2 protein as antigen for serological diagnosis and materials for vaccine production. An ELISA method using recombinant ORF2 antigen for detecting specific antibodies against PCV2 in swine sera was also established. 286 field serum samples were used to develop an ELISA to detect specific antibodies against PCV2 and compared with IPMA and commercial ELISA kit. The tested results indicated that the ELISA using recombinant ORF2 protein as antigen possessed a specific level reaching 97.16% and a sensitivity of 100%. This indicates that our ELISA is suitable for serological diagnosis in order to detect specific antibodies against PCV2 in swine sera and for epidemiological surveys of PCV2 associated diseases.