Ⅰ群4型禽腺病毒Y17215-1株体外增殖规律及免疫原性研究

In vitro Proliferation and Immunogenicity Studies of Avian Adenovirus Group 1 Type 4 Strain Y7215-1

为探讨禽腺病毒4型分离株Y17215-1的体外增殖特性和免疫原性,本研究以LMH细胞为模型,摸索Y17215-1株最佳接种剂量和收获时间;通过活毒滴鼻接种和灭活疫苗肌肉注射的方式免疫SPF鸡,测定其免疫原性。结果显示:Y17215-1株0.1 MOI接种LMH细胞,培养48~72 h病毒滴度达到峰值108.625 TCID_(50)/mL。该病毒经肌肉注射对42日龄SPF鸡具有较强致病性,LD_(50)为103.000 TCID_(50)/0.2 mL。以10^(7.676) TCID_(50)的Y17215-1株滴鼻免疫21日龄SPF鸡,免疫后7 d 100%试验鸡产生中和抗体,14 d达到高峰。以Y17215-1株制备灭活疫苗肌肉注射免疫21日龄SPF鸡(10^(7.676) TCID_(50)/羽),免疫后7 d 70%试验鸡产生中和抗体,21 d达到高峰。在免疫后21 d用1000LD_(50)的Y17215-1株进行攻毒,活毒和灭活疫苗的保护率均为100%。以上结果表明:Y17215-1株具有很好的体外增殖特性和免疫原性,可以作为候选疫苗毒株。

To explore the proliferation characteristics and immunogenicity of avian adenovirus type 4 strain Y17215-1,LMH cells were used as a model to study the optimal inoculation dose and harvest time.SPF chickens were immunized via nasal drip of live virus and intramuscular injection of inactivated vaccine.The results showed that the virus titer of the Y17215-1 strain reached the peak of 108.625 TCID_(50)/mL after 48-72 hours of inoculation into LMH cells at 1:100 dilution.The virus was highly pathogenic to 42-day-old SPF chickens via intramuscular injection and the LD_(50) was 103.000 TCID_(50)/0.2 mL.21-day-old SPF chickens were intranasally immunized with 10^(7.676) TCID_(50) of Y17215-1 strain.The neutralizing antibodies were produced in 100%of the chickens at day 7 post immunization and peaked at day 14 days.21-day-old SPF chickens were intramuscularly immunized with the dose of 10^(7.676) TCID_(50)/feather of inactivated In vitro Proliferation and Immunogenicity Studies of Avian Adenovirus Group 1 Type 4 Strain Y7215-1 vaccine prepared from strain Y17215-1.Neutralizing antibodies were detected in 70%of the tested chickens at day 7 post immunization and peaked at day 21.The immunized chickens were challenged with 1000 LD_(50) of Y17215-1 strain at day 21 post immunization and the protection rates were 100%for chickens immunized with either live or inactivated vaccines.The above results showed that the Y17215-1 strain had good in vitro proliferation and immunogenicity in chickens and might be used as a candidate vaccine strain.