BCR免疫组库分析SARS-CoV-2疫苗同源及异源免疫B细胞应答差异  

Differences Between Heterologous Vaccination and Homologous Vaccination of SARS-CoV-2 by BCR Repertoire

作　　者：宋彦丽 孙誉芳 鲍春婷 王浇磊 权娅茹[2] 李长贵[2] SONG Yanli;SUN Yufang;BAO Chunting;WANG Jiaolei;QUAN Yaru;LI Changgui(Research Division 2 of Viral Vaccines,Wuhan Institution of Biological Product Co.Ltd,Wuhan 430207,China;Research Division of RespiratoryVirus Vaccine,National Institute forFood and Drug Control,Beijing 102600,China)

机构地区：[1]武汉生物制品研究所有限责任公司病毒性疫苗研究二室,武汉430207 [2]中国食品药品检定研究院呼吸道病毒疫苗室,北京102600

出　　处：《病毒学报》2025年第1期23-32,共10页Chinese Journal of Virology

摘　　要：比较新型冠状病毒(Severe acute respiratory syndrome coronavirus 2,SARS-CoV-2)灭活疫苗(Inactivated vaccine,In)和腺病毒载体疫苗(Adenoviral vector vaccine,Ad)同源和异源免疫引起的B细胞抗原受体(B-cell receptor,BCR)差异,探究SARS-CoV-2疫苗异源加强引起的抗体应答增强的原因。分别给小鼠同源免疫灭活疫苗In~4In、异源免疫3InAd,并于每次免疫10 d后采外周血检测各组血清针对SARS-CoV-2原型株和XBB.1.16变异株的中和抗体水平;提取同源和异源免疫后小鼠脾脏RNA,逆转录为cDNA后,对BCR重链的CDR3区序列进行BCR免疫组库测序,分析同源和异源免疫策略中CDR3的氨基酸长度多样性、V基因使用频率、V-J基因配对频率、BCR克隆多样性和克隆扩增水平。结果显示,异源3InAd组引起的针对原型株和XBB.1.16毒株的中和抗体水平显著高于同源免疫组;3InAd组CDR3氨基酸长度分布与同源免疫In~4In组不同;3InAd组V基因IGHV11-1、IGHV4-2使用频率显著高于同源4In组,IGHV5-6基因的使用频率低于4In组,IGHV9-3基因的使用频率在同源和异源免疫组无差异;同源免疫In~4In后,BCR克隆种类逐渐丰富,但BCR top 50的频率逐渐降低;3InAd组BCR种类丰富性与4In组相比没有明显增加,BCR top 50的频率逐渐增加,表明异源免疫增加了主要BCR克隆的扩增。本研究发现SARS-CoV-2异源免疫改变了B细胞CDR3长度、V基因频率、V-J基因配对频率、BCR种类多样性和BCR克隆扩增水平。We wished to compare differences in homologous vaccination and heterologous vaccination of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and explore the mechanisms of antibody enhancement in heterologous immunization.Mice underwent homologous immunization with 1-4 doses In,or heterologous vaccination with 3InAd.Blood was collected 10 days after each vaccination.Then,neutralizing antibodies against the prototype strains of SARS-CoV-2 and the XBB.1.16 variant in each group were detected.RNA was extracted from homologous and heterologous groups and reverse-transcribed into complementary-DNA.Then,complementarity-determining region 3(CDR3)of the B-cell receptor(BCR)heavy chain was sequenced.Diversity in the amino-acid length,frequency of V gene usage,frequency of V-J gene pairing,BCR clonal diversity,and clonal expansion CDR3 in homologous and heterologous strategies were analyzed.Compared with homologous groups,the heterologous 3InAd group showed significantly higher neutralizing antibody titers against prototype and XBB.1.16 strains.The distribution of amino-acid length of CDR3 in the 3InAd group was different from that in the homologous group.Frequencies of IGHV11-1 and IGHV4-2 in the V gene in the 3InAd group were significantly higher than those in the 4In group.The frequencies of IGHV5-6 genes were lower than those in the 4In group.There were no differences in the frequencies of IGHV9-3 between the 3InAd group and 4In group.The diversity of BCR clones was increased,but the frequencies of the BCR top-50 was decreased gradually in homologous In–4In groups.In the 3InAd group,the diversity of BCR did not increase significantly compared with that in the 4In group,but BCR top-50 expansion increased,indicating that heterologous immunization increased the expansion of major BCR clones.We concluded that SARS-CoV-2heterologous immunization changes B-cell CDR3 length,frequencies of V-gene usage and V-J gene pairing,as well as the diversity of BCR species and expansion of BCR clones.

关 键 词：BCR免疫组库 同源免疫 异源免疫 SARS-CoV-2 灭活疫苗 腺病毒载体疫苗 

分 类 号：R373.1[医药卫生—病原生物学]