Ge Shikun, Wu Rao, Zhou Tingting, Liu Xiang, Zhu Jin, Zhang Xiaoying
School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, China.
Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, Campus de Gualtar, 4710-057, Braga, Portugal.
AMB Express. 2022 Feb 12;12(1):18. doi: 10.1186/s13568-022-01355-4.
As severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to spread globally, a series of vaccines, antibodies and drugs have been developed to combat coronavirus disease 2019 (COVID-19). High specific antibodies are powerful tool for the development of immunoassay and providing passive immunotherapy against SARS-CoV-2 and expected with large scale production. SARS-CoV-2 S1 protein was expressed in E. coli BL21 and purified by immobilized metal affinity chromatography, as antigen used to immunize hens, the specific IgY antibodies were extracted form egg yolk by PEG-6000 precipitation, and the titer of anti-S1 IgY antibody reached 1:10,000. IgY single chain variable fragment antibody (IgY-scFv) was generated by using phage display technology and the IgY-scFv showed high binding sensitivity and capacity to S1 protein of SARS-CoV-2, and the minimum detectable antigen S1 protein concentration was 6 ng/µL. The docking study showed that the multiple epitopes on the IgY-scFv interacted with multiple residues on SARS-CoV-2 S1 RBD to form hydrogen bonds. This preliminary study suggests that IgY and IgY-scFv are suitable candidates for the development of immunoassay and passive immunotherapy for COVID-19 to humans and animals.
随着严重急性呼吸综合征冠状病毒2（SARS-CoV-2）在全球持续传播，一系列疫苗、抗体和药物已被研发用于对抗2019冠状病毒病（COVID-19）。高特异性抗体是开发免疫测定以及提供针对SARS-CoV-2的被动免疫疗法的有力工具，并有望大规模生产。SARS-CoV-2 S1蛋白在大肠杆菌BL21中表达，并通过固定化金属亲和层析进行纯化，作为抗原用于免疫母鸡，通过PEG-6000沉淀从蛋黄中提取特异性IgY抗体，抗S1 IgY抗体的效价达到1:10,000。利用噬菌体展示技术产生了IgY单链可变片段抗体（IgY-scFv），该IgY-scFv对SARS-CoV-2的S1蛋白表现出高结合敏感性和结合能力，最小可检测抗原S1蛋白浓度为6 ng/µL。对接研究表明，IgY-scFv上的多个表位与SARS-CoV-2 S1受体结合域上的多个残基相互作用形成氢键。这项初步研究表明，IgY和IgY-scFv是开发用于人类和动物COVID-19免疫测定和被动免疫疗法的合适候选物。
