Yan Hongjian, Chi Zengna, Zhao Hui, Zhang Yawen, Zhang Yuduo, Wang Yixin, Chang Shuang, Zhao Peng
College of Veterinary Medicine, Shandong Agricultural University, Tai'an 271018, China.
Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Tai'an 271018, China.
Vet Sci. 2022 Dec 5;9(12):676. doi: 10.3390/vetsci9120676.
Avian hepatitis E virus (HEV) is the main etiologic pathogen of chicken big liver and spleen disease which is widely prevalent in China in recent years. However, due to the lack of a highly effective culture system in vitro, a genetically engineered subunit vaccine is the main direction of vaccine development. In this study, ORF3 genes of VaHEV strain from laying hens and YT-aHEV strain from broilers were amplified, respectively, and ORF3 protein was successfully expressed by prokaryotic expression system. The serum samples were collected periodically to detect avian HEV antibodies by indirect immunofluorescence after specific pathogen free chickens immunized with the two proteins and their mixed proteins, the results showed that all serum samples were positive for antibodies to avian HEV. The antibody-positive chickens were artificially challenged with the cell-adapted strain YT-aHEV strain. The chickens from the immunized control group were infected successfully; no fecal detoxification was detected in the immunized group. In this study, two representative strains of ORF3 subunit vaccines of laying hens and broilers were prepared by prokaryotic expression, the immune effects of different proteins of these were evaluated through immunization and challenge studies in vivo, which provided a new technical possibility for prevention and control of avian HEV.
禽戊型肝炎病毒（HEV）是近年来在中国广泛流行的鸡大肝大脾病的主要病原。然而，由于缺乏高效的体外培养系统，基因工程亚单位疫苗是疫苗研发的主要方向。本研究分别扩增了蛋鸡源VaHEV株和肉鸡源YT-aHEV株的ORF3基因，并通过原核表达系统成功表达了ORF3蛋白。将这两种蛋白及其混合蛋白免疫无特定病原体鸡后，定期采集血清样本，采用间接免疫荧光法检测禽HEV抗体，结果显示所有血清样本的禽HEV抗体均为阳性。对抗体阳性鸡用细胞适应株YT-aHEV株进行人工攻毒。免疫对照组鸡成功感染，免疫组未检测到粪便排毒。本研究通过原核表达制备了蛋鸡和肉鸡ORF3亚单位疫苗的两个代表性毒株，通过体内免疫和攻毒试验评估了不同蛋白的免疫效果，为禽HEV的防控提供了新的技术可能性。
