Generation and Immunogenicity of a Recombinant Adenovirus Co-Expressing the E2 Protein of Classical SwineFever Virus and the GP5 Protein of Porcine Reproduction and Respiratory Syndrome Virus

• Published in: 中国农业科学：英文版 Vol. 10; no. 11; pp. 1781 - 1791
• Main Author: LI Hong-yun SUN Yuan ZHANG Xing-juan CHANG Tian-ming WANG Xiang-peng HE Fan HUANG Jun-hua QIU Hua-ji
• Format: Journal Article
• Language: English
• Published: 2011
• Subjects: E2蛋白; GP5蛋白; PRRSV; 免疫原性; 共表达; 猪瘟病毒; 猪繁殖与呼吸综合征病毒; 重组腺病毒
• ISSN: 1671-2927

Classical swine fever （CSF） and porcine reproduction and respiratory syndrome （PRRS） are both economically important, highly contagious diseases of swine worldwide. To develop an effective vaccine to control these two diseases, we constructed a recombinant adenovirus rAdV-GP52AE2, using a replication-defective human adenovirus serotype 5 as a delivery vector, to co-express the GP5 protein of highly pathogenic porcine reproduction and respiratory syndrome virus （PRRSV） and the E2 protein of classical swine fever virus （CSFV）. Foot-and-mouth disease virus （FMDV） 2A peptide was used as a linker between the GP5 and E2 proteins to allow automatic self-cleavage of the polyprotein. The GP5 and E2 genes were expressed as demonstrated by immunofluorescence assay and Western blotting. Immunization of mice resulted in a CSFV-neutralizing antibody titer of 1：128 and a PRRSV-neutralizing antibody titer of 1：16. The lymphoproliferative responses were detected by Cell Counting Kit-8 assay and the stimulation index of CFSV-specific and PRRSV-specific lymphocytes in the rAdV-GP52AE2 group was significantly higher than that in the negative control group. The results show that rAdV-GP52AE2 can induce both effective humoral and cell-mediated immune responses in mice. The protective efficacy of the recombinant virus against CSF was evaluated in immunized rabbits, which were protected from fever induced by challenge with C-strain. Our study provides supporting evidence for the use of FMDV 2A to develop a bivalent genetically-engineered vaccine.