College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China; Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangdong, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Guangzhou 510642, China.
College of Animal Science, South China Agricultural University, Guangzhou 510642, China; Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China; Key Laboratory of Animal Health Aquaculture and Environmental Control, Guangdong, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding, Guangzhou 510642, China; South China Collaborative Innovation Center for Poultry Disease Control and Product Safety, Guangzhou 510642, China.
Poult Sci. 2020 Sep;99(9):4334-4342. doi: 10.1016/j.psj.2020.06.012. Epub 2020 Jun 24.
The H9N2 avian influenza virus has been widely spread in poultry around the world. It is proved to the world that the avian influenza virus can directly infect human beings without any intermediate host adaptation in "1997 Hong Kong avian influenza case," which shows that the avian influenza virus not only causes significant losses to the poultry industry but also affects human health. In this study, we aimed to address the problem of low protection of avian H9N2 subtype influenza virus vaccine against H9N2 wild-type virus. We have rescued the H9.4.2.5 branched avian influenza virus isolated in South China by reverse genetics technology. We have recombined these virus (rHA/NA-GD37 and rHA/NA-GD38) which contain hemagglutinin and neuraminidase genes from the H9N2 avian influenza virus (MN064850 or MN064851) and 6 internal genes from the avian influenza virus (KY785906). We compared the biological properties of the virus for example virus proliferation, virus elution, thermostability, and pH stability. Then, we evaluated the immune effects between rHA/NA-GD37 and GD37, which show that the recombinant avian influenza virus-inactivated vaccine can stimulate chickens to produce higher antibody titers and produce little inflammatory response after the challenge. It is noticeable that the recombinant virus-inactivated vaccine had better immune impact than the wild-type inactivated vaccine. Generally speaking, this study provides a new virus strain for the development of a H9N2 vaccine.
H9N2 禽流感病毒已在世界范围内广泛传播于家禽中。“1997 年香港禽流感病例”向世界证明，禽流感病毒可以在没有任何中间宿主适应的情况下直接感染人类，这表明禽流感病毒不仅对家禽业造成重大损失，还影响人类健康。在这项研究中，我们旨在解决禽 H9N2 亚型流感病毒疫苗对 H9N2 野型病毒保护率低的问题。我们已经通过反向遗传学技术拯救了在中国南方分离的 H9.4.2.5 分支禽流感病毒。我们重组了这些病毒（rHA/NA-GD37 和 rHA/NA-GD38），它们含有来自 H9N2 禽流感病毒（MN064850 或 MN064851）的血凝素和神经氨酸酶基因以及来自禽流感病毒的 6 个内部基因（KY785906）。我们比较了病毒的生物学特性，例如病毒增殖、病毒洗脱、热稳定性和 pH 稳定性。然后，我们评估了 rHA/NA-GD37 和 GD37 之间的免疫效果，结果表明，重组禽流感病毒灭活疫苗可以刺激鸡产生更高的抗体滴度，并在攻毒后产生较小的炎症反应。值得注意的是，重组病毒灭活疫苗的免疫效果优于野生型灭活疫苗。总的来说，这项研究为 H9N2 疫苗的开发提供了一种新的病毒株。
