The Immune Responses and Protection Efficacy of DNA and Subunit Vaccines Containing Infectious Bronchitis Virus S1, M or N in Chickens against Infectious Bronchitis

• Main Authors: Yi-Ting Liou, 劉羿廷
• Other Authors: 謝明昆
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/67434845127338022463

碩士 === 國立中興大學 === 微生物暨公共衛生學研究所 === 100 === Infectious Bronchitis virus (IBV) causes acute and contagious diseases in chickens with significant impact on the poultry industry worldwide. The objective of this study is to develop DNA and subunit vaccines containing S1, M or N protein of infectious bronchitis virus (IBV) to protect chickens against IBV challenge. The individual S1, M or N gene was constructed into pTriEx vector as pTriEx-3/S1, pTriEx-3/M and pTriEx-3/N, and transformed into E. coli for plasmid preparation or protein expression. All the DNA and subunit vaccines were confirmed by immunefluorescence assay and Western blotting, respectively. Chickens were vaccinated from one week of age by intramuscular injection weekly three times for DNA vaccines and two times for subunit vaccines. Chickens were challenged by IBV and observed for one or two weeks. All sera were collected weekly and detected by commercial IBV ELISA kit. Chickens were sacrificed and kidney lesion score was given to each chicken according to the severity of damage and swelling in kidney. Chickens vaccinated with N DNA vaccines had significantly higher anti-IBV ELISA titers than those vaccinated with M and S1 DNA vaccines (p < 0.05) before challenge, however, the lesion score of chickens vaccinated with pTriEx-3/N DNA vaccines did not have significant differences when compared to chickens in the challenge control groups (p > 0.05). Chickens vaccinated with pTriEx-3/S1 DNA/subunit vaccines and pTriEx-3/M DNA vaccine did not have significantly different ELISA titers than those in negative control before challenge and did not have significantly different lesion scores than those in challenge control, either. Chickens vaccinated with M or N subunit vaccines had significantly higher anti-IBV ELISA titers than those in other groups (p < 0.05) before challenge. The lesion scores of groups vaccinated with either DNA or subunit vaccines expressing M or N protein did not have significant differences when compared to chickens in negative control groups (p > 0.05). The results showed that M and N subunit vaccines could evoke immune response and provide protection against IBV challenge.