抗新型冠状病毒分泌型IgA的构建及其经鼻给药的生物分布研究  

Construction of secretory IgAagainst SARS-CoV-2 and its biodistribution through nasal administration in mice

作　　者：黄平 张冠英 迟象阳 孙韩聪 房婷 于长明 陈薇 HUANG Ping;ZHANG Guanying;CHI Xiangyang;SUN Hancong;FANG Ting;YU Changming;CHEN Wei(Academy of Military Medical Sciences,Academy of Military Sciences,Beijing 100071,China)

机构地区：[1]军事科学院军事医学研究院,北京100071

出　　处：《军事医学》2024年第7期501-508,共8页Military Medical Sciences

摘　　要：目的以实验室前期开发的1株IgG型抗新型冠状病毒中和抗体ZW2G10为模板,构建得到分泌型IgA(sIgA)并进行活性评价,明确sIgA经鼻给药后在ICR小鼠体内的生物分布。方法sIgA经表达、纯化和鉴定后,通过ELISA和假病毒中和实验评价其结合活性和中和活性。sIgA偶联Alexa Fluor 750荧光染料,对小鼠进行滴鼻,活体成像观察sIgA的体内生物分布;将小鼠解剖后,观察sIgA在各器官组织的分布状况。结果与IgG型抗体相比,sIgA保留了与SARS⁃CoV⁃2 S蛋白的结合能力,其中和能力得到增强。sIgA以1 mg/kg的单次剂量滴鼻后,可在小鼠肺部留存72 h以上;在其他器官组织中,仅鼻腔和胃肠道在滴鼻后8 h内检测到抗体存在,在心脏、肝脏、肾脏、脾脏、脑、膀胱和血液中均未检测到抗体存在。结论成功构建通用、高效的sIgA表达体系,明确了sIgA经鼻给药后可有效针对呼吸道和肺部,sIgA有望成为提供即时被动免疫保护的潜在药物。Objective To construct secretory IgA(sIgA)based on the previously screened IgG neutralizing antibody ZW2G10 against SARS⁃CoV⁃2,evaluate its activity and find out about the biodistribution of sIgA in ICR mice after nasal administration.Methods After expression,purification,and identification,sIgA was evaluated for its binding and neutralizing activity through ELISA and pseudovirus⁃based neutralization assays.SIgA was coupled with Alexa Fluor 750 dye and administered to mice via nasal administration.In vivo imaging was used to observe the biodistribution of sIgA.After dissection of the mice,the biodistribution of sIgA in various tissues and organs was observed.Results Compared with IgG,sIgA retained the binding ability to SARS⁃CoV⁃2 S proteins,and its neutralizing ability was enhanced.After nasal administration of a single dose of 1 mg/kg,sIgA could be retained in the lungs of mice for more than 72 hours.SIgA could be detected only in the nasal cavity and gastrointestinal tract within 8 h of administration,but not in the heart,liver,kidney,spleen,brain,bladder or blood.Conclusion In this study,a universal and efficient sIgA expression system has been established.sIgA can effectively target the respiratory tract and lungs after nasal administration.SIgA is expected to become a potential drug that provides immediate passive immune protection.

关 键 词：新型冠状病毒 分泌型IGA 抗体工程 经鼻给药 生物分布 活体成像 

分 类 号：Q816[生物学—生物工程] R392.1[医药卫生—免疫学]