新型冠状病毒BA.2亚单位疫苗的原核表达和免疫效果评价  

Prokaryotic expression and immune effect evaluation of SARS-CoV-2 BA.2 subunit vaccine

作　　者：闫宇涵 苏秋东[1] 伊瑶[1] 沈立萍[1] 毕胜利[1] Yan Yuhan;Su Qiudong;Yi Yao;Shen Liping;Bi Shengli(National Institute for Viral Disease Control and Prevention,Chinese Center for Disease Control and Prevention,Beijing 102206,China)

机构地区：[1]中国疾病预防控制中心病毒病预防控制所,北京102206

出　　处：《中华实验和临床病毒学杂志》2024年第1期7-14,共8页Chinese Journal of Experimental and Clinical Virology

摘　　要：目的利用原核表达系统制备针对新型冠状病毒BA.2变异株亚单位疫苗并评价其免疫原性。方法利用分子克隆技术同时构建BA.2变异株RBD以及RBD与TT-P2表位串联的重组质粒, 通过蛋白纯化技术获得重组蛋白So和Sot。蛋白So/Sot作为免疫原与Al(OH)_(3)佐剂混匀后对小鼠进行肌肉注射免疫以评价细胞和体液免疫效果。结果原核系统成功表达目的蛋白且透析复性后获得高纯度可溶性蛋白。Sot组分泌IFN-γ和IL-4的抗原特异性T淋巴细胞数(213.7±0.6和311.7±1.5)均显著高于So组(94.3±16.8和185.7±4.2)(P<0.001)。Sot组诱导小鼠产生的血清抗体水平高于So组, 针对BA.2毒株的中和抗体几何平均滴度(geometric mean titer, GMT)分别为588和337(P<0.05)。Sot蛋白能诱导产生Th1/Th2混合型免疫应答但以Th2型为主。结论原核系统表达的蛋白亚单位疫苗具有良好的细胞和体液免疫原性, 为新冠病毒Omicron变异株蛋白亚单位疫苗的研发提供了有力的理论依据。Objective A subunit vaccine against SARS-CoV-2 BA.2 variant was prepared by prokaryotic expression system and its immunogenicity was evaluated.Methods The recombinant plasmid of BA.2 variant RBD and the tandem of RBD and TT-P2 epitopes was constructed by molecular cloning technology,and recombinant proteins So and Sot were obtained by protein purification technology.Mice were immunized by intramuscular injection after mixing protein So/Sot as immunogens with Al(OH)_(3) adjuvant to evaluate the effect of cellular and humoral immunity.Results High purity soluble protein were obtained by dialysis and renaturation after expressed by prokaryotic system.The number of antigen-specific T lymphocytes secreting IFN-γand IL-4(213.7±0.6 and 311.7±1.5)in the Sot group induced by mice was significantly higher than that in the So group(94.3±16.8 and 185.7±4.2)(P<0.001).The serum antibody level induced by Sot group was higher than that in the So group,the geometric mean titer(GMT)of neutralizing antibodies against BA.2 strain were 588 and 337,respectively(P<0.05).Sot protein induced Th1/Th2 mixed type immune response with the predominance of Th2 type.Conclusions The protein subunit vaccine expressed by the prokaryotic system have excellent cellular and humoral immunogenicity,which provides a strong theoretical basis for the development of the protein subunit vaccines of the SARS-CoV-2 Omicron variant.

关 键 词：新型冠状病毒 受体结合域 亚单位疫苗 原核表达 免疫原性 

分 类 号：R392[医药卫生—免疫学]