College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China.
College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, PR China; Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu, PR China; Jiangsu Research Centre of Engineering and Technology for Prevention and Control of Poultry Disease, Yangzhou, Jiangsu, PR China.
Vaccine. 2019 Mar 22;37(13):1736-1742. doi: 10.1016/j.vaccine.2019.02.012. Epub 2019 Feb 20.
Antigenic drift of H9N2 low pathogenic avian influenza viruses (AIV) may result in vaccination failure in the poultry industry and thus a cross-protective vaccine against H9N2 AIV is highly desirable.
A series of H9N2 recombinant viruses with the internal genes of A/Puerto Rico/8/34 (H1N1, PR8) were generated, based on the compatibility between HA and NA, the effect of HA deglycosylation, and protective antigenic epitopes in HA. After evaluation of their biological and immunological characteristics, three recombinant AIVs with the internal genes of the Y280-like strain SN were selected for protective efficacy studies.
The recombinant viruses rHANA, rHA-△200, rHA-△287, and rHA-R92G-E93K displayed good cross reactivity and induced higher neutralization antibody titers against both SN and the F98-like strain YZ4. Furthermore, those recombinant viruses had a higher EID in chicken embryos after the replacement of internal-gene backbone from PR8 to SN. The rSNHA-△200 induced better protection in immunized chickens against challenge of homologous and heterologous H9N2 avian influenza viruses when compared with the wild type strain.
The recombinant virus rSNHA-△200 can be used as a potential broad-spectrum vaccine against H9N2 avian influenza.
H9N2 低致病性禽流感病毒（AIV）的抗原漂移可能导致家禽业疫苗接种失败，因此，迫切需要针对 H9N2 AIV 的交叉保护疫苗。
基于 HA 和 NA 的兼容性、HA 去糖基化的效果以及 HA 中的保护性抗原表位，生成了一系列具有 A/Puerto Rico/8/34（H1N1，PR8）内部基因的 H9N2 重组病毒。在评估了它们的生物学和免疫学特性后，选择了三个具有 Y280 样株 SN 内部基因的重组 AIV 进行保护效力研究。
重组病毒 rHANA、rHA-△200、rHA-△287 和 rHA-R92G-E93K 表现出良好的交叉反应性，并诱导了针对 SN 和 F98 样株 YZ4 的更高中和抗体滴度。此外，这些重组病毒在将内部基因骨架从 PR8 替换为 SN 后，在鸡胚中的 EID 更高。与野生型相比，rSNHA-△200 诱导免疫鸡对同源和异源 H9N2 禽流感病毒的攻毒更好的保护。
重组病毒 rSNHA-△200 可用作针对 H9N2 禽流感的潜在广谱疫苗。
