人呼吸道冠状病毒229E和NL63小鼠感染动物模型快速构建及应用研究

季节性呼吸道冠状病毒229E和NL63在世界范围内广泛流行。在儿童、老年和免疫缺陷患者可引起重症肺炎，甚至死亡。由于动物模型缺乏，229E和NL63致病机制研究严重滞后，也无有效的药物和疫苗。团队前期利用表达新冠病毒（SARS-CoV-2）受体hACE2的腺病毒载体，快速构建了其小鼠感染动物模型，广泛应用于新冠肺炎（COVID-19）研究。本项目将利用表达229E受体hAPN和NL63受体hACE2腺病毒载体，滴鼻转导不同遗传背景小鼠，使其肺部表达相关病毒受体。病毒感染后，检测肺组织病毒复制、病毒抗原表达、病理损伤以及诱导的体液和细胞免疫应答情况，并利用此动物模型评估广谱抗病毒药物和疫苗。最后，在动物水平上阐明季节性冠状病毒和新冠病毒之间交叉免疫应答及保护作用机制。229E和NL63小鼠感染动物模型的构建不但为冠状病毒致病机制研究提供平台，也可促进广谱抗冠状病毒药物和疫苗的研发。

Seasonal human respiratory coronavirus 229E (hCoV-229E) and NL63 (hCoV-NL63) are present worldwide. They cause severe pneumonia or even death in children, elderly and immunocompromised patients. Due to lack of animal model, the studies on pathogenesis of 229E and NL63 infection are delayed and there are no effective antiviral drugs or vaccines approved for treatment or prevention. Recently, we rapidly generated a broadly useful model for COVID-19 by prior transduction with adenoviral vectors expressing the human host-cell receptor hACE2. Here, we will develop 229E and NL63 mouse models by transducing mice with different genetic backgrounds with adenoviral vectors expressing the 229E receptor aminopeptidase N (Ad5-hAPN) and NL63 receptor angiotensin-converting enzyme 2 (Ad5-hACE2), respectively. After transduced mice are infected by 229E or NL63, virus replication, viral antigen expression, lung pathological change, and virus specific antibody and T cell response will be detected. The mouse models will be used to evaluate broad-spectrum antiviral drugs and vaccines. Finally, the infected mice will be used to investigate potential cross-reactive immune response between seasonal respiratory coronavirus and SARS-CoV-2, and the mechanism of cross-protection will be elucidated. Development of 229E and NL63 infection mouse model will not only provide tools for pathogenesis study of coronaviruses, but also promote the research of broad-spectrum antiviral drugs and vaccines.