结核分枝杆菌CFP21抗原的HLA-A*0201/*03限制性细胞毒T淋巴细胞表位预测

Prediction of HLA-A*0201/*03-restricted cytotoxic T lymphocyte epitopes in Mycobacterium tuberculosis CFP21 antigen

目的:探寻结核分枝杆菌CFP21抗原的同时针对HLA-A*0201/*03型别的广谱细胞毒T淋巴细胞(CTL)表位。方法:对结核分枝杆菌CFP21抗原的HLA-A*0201候选肽,利用在线数据库预测HLA-A*03限制性的天然表位肽,通过氨基酸置换适当修饰获得对应的改造肽。通过T2A3细胞结合力实验筛选候选肽,用于细胞毒活性实验。结果:在线数据库预测共获得4条母体肽和3条改造肽。结合力实验显示,改造肽p134-1Y2L、p134-1Y2L9L和母体肽p134与HLA-A*03分子均具有较高的结合力。改造肽p134-1Y2L9L和母体肽p134均能诱导CTL反应,但p134诱导出的CTL对靶细胞具有更强的杀伤效应。结论:p134(AVADHVAAV)是同时针对HLA-A*0201/*03型别的广谱CTL表位。

Aim：To explore the HLA-A＊0201/＊03 cytotoxic T lymphocyte（CTL） epitopes from Mycobacterium tuberculosis CFP21.Methods：The online database was applied to predict the HLA-A＊03 restricted natural epitope peptide based on the HLA-A＊0201 candidate peptides of CFP21 antigen,and modified epitopes were obtained by amino acid replacement.T2A3 cell line was used to determine the binding affinity of the candidate peptides,and the candidate peptides were selected for subsequent cytotoxicity assay.Results：Four native epitopes and 3 modified epitopes were obtained.The binding affinity of the modified epitope p134-1Y2L,p134-1Y2L9L and the native p134 towards HLA-A＊03 molecule was relatively high.Cytotoxicity assay showed that both the modified epitope p134-1Y2L9L and the native peptide p134 could induce potent CTL response,and p134-induced CTLs could potently lyse the peptide-loaded target cells.Conclusion：p134（AVADHVAAV） could be a broad spectrum CTL epitope towards HLA-A＊0201/＊03.