SSX基因家族HLA-A0201限制性CTL共同表位预测、鉴定及其交叉反应性研究

发布时间：2018-06-06 12:05

本文选题：SSX + HLA-A2限制性　；参考：《第三军医大学》2006年硕士论文

【摘要】： 基于抗原表位肽的疫苗,由于其中表位肽的化学成分相对简单、稳定、容易构建、可以避免各种污染及潜在的致癌物质等方面的优势,已经成为肿瘤免疫治疗研究的主要策略之一。目前这种疫苗形式中的抗原表位肽主要是来源于肿瘤/睾丸抗原(Cancer/testis antigen,CT抗原)。SSX基因家族是CT抗原之一,与其它多成员组成的CT抗原家族一样,它由9个不同成员组成。在某一种肿瘤细胞中不会同时表达所有SSX家族成员,而是仅表达其中一种或几种。如对6种不同组织类型的10个滑膜肉瘤细胞系,进行SSX-1、SSX-2、SSX-3、SSX-4、SSX-5的mRNA表达调查发现,其表达阳性率分别为90%、50%、10%、60%和50%,两种以上基因同时表达的达60%,全部此类肿瘤细胞至少表达一种上述基因。而对26例原发性肝癌(hepatocellular carcinoma,HCC)组织进行SSX-1、SSX-2和SSX-5的mRNA表达分析,其表达阳性率分别为61.5%、34.6%和46.2%,两种以上基因同时表达的有4例(15.4%),至少有一种基因表达的有17例(65.4%)。因而针对其中某一种成员的抗原表位肽肿瘤疫苗的实际应用将会存在一定的局限性。基于此,研究开发能同时针对整个SSX家族所有成员的表位肽疫苗将会有广阔的应用前景。本课题将SSX家族的9个成员分别输入林治华教授基于超基序结合量化基序列开发的CTL表位预测软件,并结合著名的美国国立卫生研究所的BIMAS软件(http://www-bimas.cit.gov/ molbio/hla_bind/)和德国海德堡生物医学信息中心根据特定肽的锚定残基和辅助残基位置的氨基酸类型来评分的SYFPEITHI软件(http://www.syfpeithi.de/),分析它们的预测结果。发现SSX57-65是所有成员中预测分值相对较高的肽片段,并且它们之间的序列相似程度非常高,仅在第1、8、9位上有所区别,而其它位点序列完全一致。根据这些结果,我们合成了可以代表SSX57-65全部成员的4条肽,即(1) P1: AMTKLGFKA (SSX-2, SSX-3, SSX-5, SSX-7, SSX-9), (2) P4: AMTKLGFNV (SSX-6, SSX-8), (3) P5: AMTKLGFKV (SSX-1), (4) P6: VMTKLGFKV (SSX-4)。在分析此4条预测表位肽与MHC-I分子结合的亲和力大小和结合稳定性的基础上,我们再用它们在体外刺激健康人PBMC,用可以评价特异性CTL的
[Abstract]:Because the epitope peptide based vaccine is relatively simple, stable and easy to construct, it can avoid all kinds of pollution and potential carcinogens. It has become one of the main strategies in tumor immunotherapy. At present, the epitope peptide of this vaccine is mainly derived from tumor / testis antigen Cancer-testis antigen.SSX gene family is one of CT antigens. In a tumor cell, all members of SSX family are not expressed at the same time, but only one or several of them are expressed. For 10 synovial sarcoma cell lines of 6 different tissue types, the mRNA expression of SSX-1pSSX-2mSSX-3nSSX-3nSX-4nSSX-5 was investigated. The positive rates of SSX-4SSX-5 expression were 90% and 50101060% and 50%, respectively. The two or more genes were expressed at the same time, and all of these tumor cells expressed at least one of the above genes. The positive rates of SSX-1mSSX-2 and SSX-5 were 61.5% and 46.2%, respectively. The positive rates of SSX-1SSX-2 and SSX-5 were 61.5% and 46.2%, respectively. There were 4 cases with two or more genes expressed at the same time and 17 cases with at least one gene expression (65.4%). Therefore, the application of epitope peptide tumor vaccine against one of its members will be limited. Therefore, the research and development of epitope peptide vaccine which can target all members of SSX family at the same time will have a wide application prospect. In this study, nine members of the SSX family were imported into the CTL epitope prediction software developed by Professor Lin Zhihua based on hypermotif and quantization sequence. The SYFPEITHI software named http: / www-bimas.cit.gov. / molbior-hla bindr.) and Heidelberg Biomedical Information Center in Germany rated the amino acid types of anchored residues and auxiliary residues on the basis of the amino acid types of specific peptide anchoring residues and auxiliary residues, and then analyzed their prediction results by using SYFPEITHI software named http: / www-bimas.cit.gov. / molbior.hla-bindr /) and the Heidelberg Biomedical Information Center in Germany, according to the amino acid types of the anchored and auxiliary residues of certain peptides. It was found that SSX57-65 was a peptide fragment with relatively high predictive score among all members, and the sequence similarity between them was very high, and only the difference was found in the first 89th position, while the sequence of other loci was completely consistent. On the basis of these results, we have synthesized four peptides representing all members of SSX57-65, I. e., 1) P1: AMTKLGFKA: SSX-2, SSX-3, SSX-5, SSX-7, SSX-9, 2) P4: AMTKLGFNV SSSX-6, SSX-8, P5) P5: AMTKLGFKV SSX-1, 4) P6: VMTKLGFKV. Based on the analysis of the binding affinity and binding stability of these four epitope peptides to MHC-I molecules, we used them to stimulate PBMCs in vitro and to evaluate the specific CTL.
【学位授予单位】：第三军医大学
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R392

【引证文献】