Hu Jixiong, Li Guopan, Wang Xi, Cai Lianshen, Rong Mingxuan, Li Huan, Xie Ming, Zhang Zhixiang, Rong Jun
College of Life Science, Yangtze University, No. 88 Jingmi Road, Jingzhou, Hubei 434000, PR China.
Jingzhou Changxin Biotechnology Co., Ltd., Jingzhou, Hubei 434000, PR China.
Virus Res. 2021 Nov;305:198552. doi: 10.1016/j.virusres.2021.198552. Epub 2021 Aug 27.
Hepatitis-hydropericardium syndrome (HHS) is widespread in China and causes high chicken mortality that results in great economic losses. A safe and effective vaccine is needed, and a subunit vaccine has potential for development. In this study, a truncated region of the FAdV-4 fiber 2 fused with coding sequence of one epitope of hexon was expressed in a prokaryotic expression system, and the immune protective effects of different doses of recombinant fiber 2 subunit vaccine on SPF chickens were compared. The recombinant fiber2 (Gly275- Pro479 aa)-hexon (Met21-Val51 aa) protein (rFH) obtained in Escherichia coli showed good solubility. The chicken survival rate at the lowest dose (2.5 μg/bird) was 75% (6/8), and at higher doses (≥5 μg/bird) was 100% (8/8) in challenge experiment. Two chickens in the 2.5 μg/bird treatment showed severe lesions, while birds in the higher dose treatments showed no obvious tissue damage as determined by histopathologic analysis of liver and spleen. Absolute quantitative real-time PCR showed no viral load in the ≥5 μg/bird treatments, but two chickens in the 2.5 μg/bird treatment had high viral loads. The challenge experience demonstrated that the rFH vaccine provided 100% protection at ≥5 μg/bird. These results suggested that rFH protein as an effective vaccine to protect against FAdV-4 and provided a new idea for the development of vaccine against HHS.
肝炎-心包积水综合征（HHS）在中国广泛流行，导致鸡的死亡率很高，造成巨大的经济损失。需要一种安全有效的疫苗，亚单位疫苗具有开发潜力。在本研究中，在原核表达系统中表达了FAdV-4纤维2的截短区域与六邻体一个表位编码序列的融合体，并比较了不同剂量的重组纤维2亚单位疫苗对SPF鸡的免疫保护效果。在大肠杆菌中获得的重组纤维2（Gly275-Pro479 aa）-六邻体（Met21-Val51 aa）蛋白（rFH）具有良好的溶解性。在攻毒试验中，最低剂量（2.5μg/只）组的鸡存活率为75%（6/8），较高剂量（≥5μg/只）组的存活率为100%（8/8）。2.5μg/只处理组的两只鸡出现严重病变，而通过肝脏和脾脏组织病理学分析确定，较高剂量处理组的鸡没有明显的组织损伤。绝对定量实时PCR显示，≥5μg/只处理组没有病毒载量，但2.5μg/只处理组的两只鸡病毒载量很高。攻毒试验表明，rFH疫苗在≥5μg/只时提供100%的保护。这些结果表明，rFH蛋白是一种有效的抗FAdV-4疫苗，为HHS疫苗的开发提供了新思路。
