新型冠状病毒疫苗免疫BALB/c小鼠后的T细胞表位鉴定  

Identification of T cell epitopes in BALB/c mice immunized with COVID-19 vaccine

作　　者：李宾 郝彦玲[1] 李丹[1] 王硕[1] 王书晖[1] 刘颖[1] LI Bin;HAO Yan-ling;LI Dan;WANG Shuo;WANG Shu-hui;LIU Ying(National Center for AIDS/STD 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性病艾滋病预防控制中心,北京102206

出　　处：《中国热带医学》2022年第4期293-299,共7页China Tropical Medicine

基　　金：国家自然科学基金(No.U20A20362)。

摘　　要：目的鉴定携带新型冠状病毒S、N和M基因的疫苗在BALB/c小鼠上的T细胞表位。方法用携带新型冠状病毒S、N和M基因的DNA疫苗和痘病毒载体疫苗免疫6~8周龄雌性BALB/c小鼠,末次免疫1个月内取小鼠脾细胞,用ELISPOT法检测其对新型冠状病毒特异性多肽的T细胞免疫反应,筛选出具有阳性反应的多肽片段,并对其表位进行预测分析。结果S、N、M基因分别鉴定出12、2、17条阳性多肽。S基因中多肽S49、S50、S100、S101、S102、S103阳性反应率为100%,且免疫刺激指数最高;覆盖M蛋白全长的41条多肽中有7条能刺激50%以上的小鼠产生阳性反应。预测分析结果显示,S、N、M基因分别有10、1、16个MHC-1 H-2限制性表位,主要位于S基因的RBD区、N基因RBD区以及M基因的跨膜区。这些表位在SARS-CoV-2及其变异株、SARS-CoV中高度保守。结论新型冠状病毒DNA疫苗和痘病毒载体疫苗诱导了针对多个基因、多个表位的特异性T细胞应答,未来通用型疫苗设计应包含能诱导细胞免疫的多个抗原,特别是包含保守表位的结构抗原。Objective To identify the T cell epitopes of the COVID-19 vaccine carrying SARS-CoV-2 S,N and M genes in BALB/c mice.Methods Groups of 6-8 week-old female BALB/c mice were immunized with DNA vaccines and recombinant vaccinia virus carrying SARS-CoV-2 S,N and M genes.The spleen cells were harvested within 1 month after thelast immunization,and the T cell immune responses to SARS-CoV-2 specific overlapping peptides were detected by enzyme-linked immunosorbent assay(ELISPOT)method.The peptides with positive reaction were screened out and MHC-1 restrictedepitopes were predicted using NetMHCpan EL 4.1.Results S,N and M genes were identified 12,2 and 17 positive peptidesrespectively.The positive reaction rate of peptides S49,S50,100,S101,S102 and S103 of S gene was 100%,with the highest immune stimulation index.Among the 41 peptides covering the full length of M protein,7 peptides could stimulate T cell responses in more than 50%of vaccinated mice.The prediction analysis showed that there were 10,1 and 16 MHC-1 H-2 restricted epitopes in S,N and M genes respectively,which mainly located in the RBD region of S and N genes,and thetransmembrane region of M gene.These epitopes were highly conserved in SARS-CoV,SARS-CoV-2 and its variants.Conclusions The COVID-19 DNA vaccine and recombinant vaccinia virus vaccine have induced SARS-CoV-2 specific Tcell responses against multiple genes and multiple epitopes.The future universal vaccine design should contain multiple antigens that can induce cellular immune responses,especially the structural antigens containing conserved epitopes.

关 键 词：T细胞表位 新型冠状病毒疫苗 主要组织相容性复合物-1 

分 类 号：R563.1[医药卫生—呼吸系统]