白血病相关抗原MLAA-34 HLA-A2^+限制性CTL表位的预测及鉴定  

Prediction and identification of HLA-A2 restricted CTL epitope derived from the leukemia-associated antigen MLAA-34

作　　者：赵建强[1,2] 何爱丽[1] 张王刚[1] 张磊[1] 古流芳[1] 张文娟[1] 

机构地区：[1]西安交通大学医学院第二附属医院血液内科,陕西西安710004 [2]西安医学院附属医院血液科,陕西西安710077

出　　处：《西安交通大学学报（医学版）》2011年第4期424-428,共5页Journal of Xi’an Jiaotong University（Medical Sciences）

基　　金：国家自然科学基金资助项目(No.30971284)~~

摘　　要：目的采用生物信息学方法预测和鉴定白血病相关抗原MLAA-34 HLA-A2+限制性CTL表位,探索基于MLAA-34为靶标的白血病免疫治疗的可能性。方法采用超基序法和量化基序法对靶抗原MLAA-34 HLA-A2+限制性CTL表位进行预测;选取评分较高且排位在前10位的抗原表位肽为候选表位肽,并进行人工合成。利用T2细胞,以肽结合试验及流式细胞术检测各候选CTL表位肽的结合亲和力[以荧光指数(fluorescence index,FI)表示];选取亲和力较高的4种多肽进行特异性CTLs的体外扩增,同时用LDH释放法对CTLs的活性进行检测。结果预测的前10位候选MLAA-34 CTL表位肽中,MLAA2(ILLKNQPKL)、MLAA3(LLTRHKVLV)、MLAA5(LLVTLI-ADL)和MLAA9(YLIKQIRDL)具有较高的亲和力,其FI分别为1.65、1.73、1.82、1.02,可作为候选表位肽进一步分析。细胞毒实验分析显示,MLAA5(LLVTLIADL)可在体外有效诱导特异性CTLs的产生,杀伤靶细胞。结论 MLAA5(LLVTLIADL)为白血病相关抗原MLAA-34的HLA-A2+限制性CTL表位,为基于MLAA-34的治疗性多肽疫苗的设计制备奠定了基础。Objective To predict and identify the leukemia-associated antigen MLAA-34 HLA-A2 restricted cytotoxic T lymphocyte（CTL） epitopes by bio-informatic methods so as to provide the probability of MLAA-34-based target for leukemia immunotherapy.Methods MLAA-34 specific HLA-A2 restricted CTL epitopes were predicted by computer supermotif algorithm combined with quantitative motif algorithm.Candidate epitopes were verified when their scores were relatively high and in the top 10,and then artificially synthesized.Affinity of the candidate epitope was examined by HLA-A2 binding assay combined with flow cytometry applying T2 cells（shown as fluorescence index,FI）.Four selected candidates with higher affinity were detected by lactate dehydrogenase（LDH） release assay kit to determine their ability to induce the generation of specific CTLs in vitro.Results Among the top 10 candidate CTL epitope peptide derived from MLAA-34,MLAA2（ILLKNQPKL）,MLAA3（LLTRHKVLV）,MLAA5（LLVTLIADL） and MLAA9（YLIKQIRDL） had a higher affinity of HLA-A2;the FI values were 1.65,1.73,1.82 and 1.05,respectively.These epitope peptides could be candidates for further analysis.The analysis of the CTLs cytotoxicity showed that the peptide MLAA5（LLVTLIADL） could effectively induce specific CTLs in vitro,and the CTLs could lyse not only the human leukemia cell line THP-1 but also the cell line T2 pulsed with MLAA3（LLTRHKVLV）.Conclusion MLAA5（LLVTLIADL） is a CTL epitope of the leukemia-associated antigen MLAA-34 presented by HLA-A2.This study provides an experimental basis for design and preparation of therapeutic vaccines based on MLAA-34.

关 键 词：白血病相关抗原 MLAA-34 CTL表位 生物信息学方法 

分 类 号：R733.7[医药卫生—肿瘤]