新型HLA-A2限制的B,C型HBV特异性CTL表位的筛选及鉴定  

Identification of an HLA-A2 restricted HBcAg-specific T cell epitope derived from HBV genotypes B and C

作　　者：任玉林[1] 张宇[2,1] 邱立鹏[1] 张小俊[1] 陈煜[3] 王福生[4] 谢尧[5] 高斌[1] 段钟平[3] 孟颂东[1] 

机构地区：[1]中国科学院微生物研究所,北京100101 [2]中国科学技术大学生命科学学院,合肥230026 [3]首都医科大学附属佑安医院,北京100069 [4]中国人民解放军第302医院,北京100039 [5]北京市地坛医院,北京100015

出　　处：《科学通报》2010年第30期2915-2924,共10页Chinese Science Bulletin

基　　金：国家自然科学基金(30970146);国家“十一五”传染病重大专项课题(2008ZX10002-005-3)资助项目

摘　　要：乙型肝炎病毒(HBV)特异性CD8+T细胞(CTL)介导的细胞免疫应答在控制HBV感染和病毒清除中至关重要,已鉴定的T细胞表位绝大多数都来自A,D基因型的乙肝病毒,而在我国流行的B,C型病毒表位研究较少.本研究合成重叠九肽肽库,通过细胞结合试验和体外重折叠实验系统筛选和鉴定B型和C型HBV核心蛋白表位,发现一个在60位氨基酸由L变异成V(L60V)而产生的新表位HBcAg60-68.表位肽能在HLA-A2/Kb转基因小鼠体内激发特异性CTL细胞免疫反应.检测HLA-A2阳性乙肝患者表位特异性CTL证明该九肽序列为体内自然加工的表位,这为研究HBV感染中特异性CTL免疫应答提供新的依据.Hepatitis B virus （HBV）-specific CD8＋ T lymphocytes （CTL） play a major role in the control and clearance of HBV infection. However, the majority of human leukocyte antigen （HLA） class I restricted epitopes have been defined in HBV genotypes A and D, but definitions are lacking in genotypes B and C, which are prevalent in China. In this study, the overlapping 9-mer peptide pools were used to screen and identify genotypes B- and C-derived HBcAg-specific T cell epitopes by HLA stabilization assays and in vitro re-folding assays. We identified a new epitope derived from a leucine to valine mutation at position 60 of the core protein （L60V）. This epitope can elicit CTL responses in HLA-A2/Kb transgenic mice. The defined HBV epitope was further characterized by investigating specific CTL responses in HLA-A2 positive patients with acute and chronic hepatitis B, indicating that the T cell epitope was naturally processed. These findings will provide a basis for the analysis of CTL responses in patients with HBV infection.

关 键 词：HBV 表位 突变 HLA-A2/Kb 转基因 

分 类 号：R392[医药卫生—免疫学]