中文摘要：

目的：预测及鉴定结核杆菌（Mycobacterium tuberculosis，Mtb）抗原Ag85C的HLA-A＊0201限制性CD8^＋CTL表位，为基于表位的结核疫苗研究提供依据。方法：应用SYFPEITHI数据库预测结核杆菌抗原Ag85C序列中可能存在的HLA-A＊0201限制性T细胞表位，利用T2细胞株分析各预测的抗原肽与HL-A＊0201分子的亲合力，选取高亲合力肽诱导特异性CTL细胞，检测各高亲合力肽刺激其特异性CTL细胞分泌的IFN-γ水平、在体外的CTL增殖反应以及细胞杀伤毒性，逐步鉴定出Ag85C的HLA-A＊0201限制性CD8^＋CTL表位。结果：SYFPEITHI数据库从Ag85C序列中预测到14条能够结合HLA—A＊0201分子的抗原肽，其中3个抗原肽（170～178aa、317～325aa和144～153aa）显示与T2细胞上HLA-A＊0201分子有高结合力，而抗原肽FLTREMPAWL（144～153aa）能够诱导大多数HLA—A＊0201阳性结核患者及PPD（＋）健康志愿者产生特异性CTL细胞，并分泌大量的IFN-γ，能够诱导CTL体外发生增殖，能够产生特异性杀伤活性。结论：成功鉴定出抗原肽FLTREMPAWL（144～153aa）结核杆菌抗原Ag85C的HLA-A＊0201限制性CD8^＋CTL表位，可作为结核疫苗设计的候选表位，为进一步研发新型有效的抗结核疫苗奠定了基础。

英文摘要：

Objective：To predict and identify HLA-A ＊ 0201 restricted CD8^＋ CTL epitopes in Mycobacterium tuberculosis （Mtb） antigen Ag85C, so as to provide evidence for epitope-based study for tuberculosis （TB） vaccine. Methods： The online database SYFPEITHI was applied to predict the potential HLA-A ＊ 0201 restricted epitopes from Ag85C, an antigen of Mycobacterium tuberculosis. T2 cell line was used to assay the affinity between the predicted peptides and HLA-A ＊ 0201 molecules. The specific CTL lines were induced from peripheral blood mononuclear cells （PBMCs） of HLA-A ＊ 0201 positive TB patients and PPD＋ healthy donors by peptides with high binding affinity to HLA-A ＊ 0201 molecules. IFN-γ production, in vitro proliferation and cytotoxicity of peptide-induced CTL were determined to screen HLA-A ＊ 0201 restricted CD8^＋ CTL epitopes from those candidates. Results： Fourteen potential epitopes were identified from the SYFPEITHI database. After binding affinity assay, 3 of the 14 peptides （170-178 aa, 317-325 aa, and 144-153 aa） were found to have high binding affinity to HLA-A＊ 0201 molecules. However, only one peptide （144-153 aa） stimulated its specific CTL to release IFN-γ, proliferate in vitro and produce specific cytotoxicity. Conclusion： We have successfully identified a HLA-A ＊ 0201 restricted CD8＋ CTL epitope of Mtb Ag85C-FLTREMPAWL（144-153 aa）, which might be a candidate epitope for TB vaccine designing. Our findings provides a basis for developing novel and effective anti-TB vaccine.