BCR组库分析乙肝疫苗接种反应及初步机理分析

Analysis of hepatitis B vaccine response by BCR repertoire sequencing

目的接种乙肝疫苗是控制乙肝流行最经济有效的方法,通过对3次乙肝注射疫苗前后的B细胞库进行高通量测序分析,探讨注射乙肝疫苗后体液免疫的动态过程。方法将志愿者接种乙肝疫苗前后的外周血样进行密度梯度离心获得淋巴细胞并提取RNA,逆转录为cDNA后对B细胞受体H链的CDR3区序列进行高通量测序,以揭示注射乙肝疫苗前后B细胞应答的变化,分析人外周血B细胞受体CDR3的多样性以及序列变化与疫苗应答之间的关系。结果志愿者外周血B细胞受体CDR3的种类和数量在接种疫苗后都有所降低,并表现出其特有的免疫学特征,包括高频取用的V、D、J家族、V-J家族配对发生了改变,CDR3区氨基酸的取用和长度分布也发生显著变化;并且接种疫苗后,志愿者外周血中存在某些寡克隆异常增殖的情况。结论大部分志愿者在接种疫苗后,B细胞受体组库的多样性等发生特征性改变,并且出现某些疫苗接种相关的寡克隆。B细胞受体高通量测序技术可以从克隆水平上监控乙肝疫苗接种后抗体产生和表达的动态变化过程。

As vaccine is the most economical and effective method to prevent the prevalence of hepatitis B virus infection, we collected peripheral blood of volunteers before and after immunization to determine the dynamic process of the humoral immunity. Lymphocytes were gotten by density gradient centrifugation from the volunteers for total RNA extraction. Then the RNA was reversely transcribed to c DNA, and CDR3 regions of BCR H chain were sequenced and analyzed. Data showed that along with the immunization, the species and numbers of BCR-CDR3 of peripheral B cells were decreased. Moreover, there were changes in other immunological features, including usage of V/D/J gene, the association of V and J gene, the usage of amino acid of CDR3 and their length. Furthermore, there existed a cluster of oligoclonal cells that proliferated actively. In conclusion, HBV vaccine injection can generally lead to some characterized change of BCR repertoire and motivate some new clone types. The high through put sequencing of BCR is a great technique to monitor the dynamic process of humoral immunity after the vaccine injection at the clonal level.