Highly efficient expression of interleukin-2 under the control of rabbit β-globin intron II gene enhances protective immune responses of porcine reproductive and respiratory syndrome (PRRS) DNA vaccine in pigs.

Abstract

Highly pathogenic porcine reproductive and respiratory syndrome virus (HP-PRRSV) had caused catastrophic losses in swine industry in China. The current inactivated vaccine provided only limited protection, and the attenuated live vaccine could protect piglets against the HP-PRRSV but there was a possibility that the attenuated virus returned to high virulence. In this study, the eukaryotic expression vector pVAX1© was modified under the control of rabbit β-globin intron II gene and the modified vector pMVAX1© was constructed. Porcine interleukin-2 (IL-2) and GP3-GP5 fusion protein of HP-PRRSV strain SD-JN were highly expressed by pMVAX1©. Mice inoculated with pMVAX1©-GP35 developed significantly higher PRRSV-specific antibody responses and T cell proliferation than those vaccinated with pVAX1©-GP35. pMVAX1©-GP35 was selected as PRRS DNA vaccine candidate and co-administrated with pVAX1©-IL-2 or pMVAX1©-IL-2 in pigs. pMVAX1©-IL-2+pMVAX1©-GP35 could provide enhanced PRRSV-specific antibody responses, T cell proliferation, Th1-type and Th2-type cytokine responses and CTL responses than pMVAX1©-GP35 and pVAX1©-IL-2+pMVAX1©-GP35. Following homologous challenge with HP-PRRSV strain SD-JN, similar with attenuated PRRS vaccine group, pigs inoculated with pMVAX1©-IL-2+pMVAX1©-GP35 showed no clinical signs, almost no lung lesions and no viremia, as compared to those in pMVAX1©-GP35 and pVAX1©-IL-2+pMVAX1©-GP35 groups. It indicated that pMVAX1©-IL-2 effectively increases humoral and cell mediated immune responses of pMVAX1©-GP35. Co-administration of pMVAX1©-IL-2 and pMVAX1©-GP35 might be attractive candidate vaccines for preventing HP-PRRSV infections.

• Authors: Yijun Du, Yu Lu, Xinglong Wang, Jing Qi, Jiyu Liu, Yue Hu, Feng Li, Jiaqiang Wu, Lihui Guo, Junzhen Liu, Haiying Tao, Wenbo Sun, Lei Chen, Xiaoyan Cong, Sufang Ren, Jianli Shi, Jun Li, Jinbao Wang, Baohua Huang, Renzhong Wan
• Journal: PloS one (PLoS One) Vol. 9 Issue 3 Pg. e90326 ( 2014) ISSN: 1932-6203 [Electronic] United States
• PMID: 24603502 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Viral
• Cytokines
• Glycoproteins
• Interleukin-2
• Vaccines, DNA
• Viral Proteins
• beta-Globins

Topics

• Animals
• Antibodies, Viral (blood, immunology)
• Blotting, Western
• Cell Proliferation
• Cytokines (immunology, metabolism)
• Female
• Gene Expression (immunology)
• Genetic Vectors (genetics)
• Glycoproteins (genetics, immunology, metabolism)
• HEK293 Cells
• Humans
• Immunity, Cellular (immunology)
• Immunity, Humoral (immunology)
• Interleukin-2 (genetics, immunology, metabolism)
• Introns (genetics)
• Lymphocytes (immunology, metabolism)
• Mice, Inbred BALB C
• Porcine Reproductive and Respiratory Syndrome (immunology, prevention & control, virology)
• Porcine respiratory and reproductive syndrome virus (genetics, immunology, metabolism)
• Rabbits
• Reverse Transcriptase Polymerase Chain Reaction
• Swine
• Vaccines, DNA (administration & dosage, genetics, immunology)
• Viral Proteins (genetics, immunology, metabolism)
• beta-Globins (genetics)