Identification of the CD4 positive helper T cell antigen that aimed at clinical application of specific immunotherapy for gastrointestinal carcinoma

在肿瘤的免疫治疗中，CD 8阳性T细胞是目前主要的免疫治疗对象。通过由MHC I类分子限制的肿瘤排斥抗原的致敏（癌症疫苗药物治疗）引起体内具有抗肿瘤作用的细胞毒性T细胞的诱导，并且呈现肿瘤的消退。然而，在大多数发现有效的患者中，效果是短暂的或不实质的。另一方面，CD 4阳性T细胞（辅助性T细胞）对于维持和增强抗肿瘤作用起重要作用。辅助性T细胞的有效感染可以加强肿瘤的免疫治疗。因此，本研究旨在开发辅助性T细胞与细胞毒性T细胞联合应用的免疫治疗新方法，在肿瘤特异性反应性T细胞的建立实验中，从两名供者外周血单个核细胞中建立了多种T细胞系。为了获得结肠癌特异性高克隆，挑选了对两种结肠癌细胞系（Colo 205和HT 29）具有交叉反应性的四种克隆。此外，根据cDNA λ噬菌体系统，从提取自HT 29和Colo 205的RNA制备cDNA文库。然而，由于大肠杆菌在T细胞反应中的高抗原性，阳性孔的确定是困难的。考虑了有效的筛选方法，但未提供具有再现性的数据，因此，当使用获得知情同意的癌症患者的淋巴细胞研究患者肿瘤组织的免疫应答性时，未分析特异性免疫治疗，并研究了进一步加强非特异性免疫治疗的可能性。用溶血性链球菌制剂（OK-432）从患者外周血单核细胞一步培养产生抗原呈递细胞树突状细胞。

In immune therapy for cancer, CD8 positive T cell was important mainly by the present. Sensitization by tumor rejection antigen restricted by an MHC class I molecule(cancer vaccine medical treatment) caused induction with cytotoxic T cell having antitumor effect in vivo, and regression of a tumor was presented. However, in most of patients who found an effect, the effect was transient or insubstantiality. On the other hand, CD4 positive T cell(helper T cell) plays an important role for maintenance and augmentation of antitumor effect. Effective inflection of helper T cell can strengthen immune therapy for cancer. Therefore, in this study we were aimed at developing the new immune therapy that used helper T cell together as well as cytotoxic T cell.In an experiment of the establishment of tumor specific reactive T cell, several kinds T cell lines were established from peripheral-blood mononuclear cells of two donors. Four kinds of clones having crossreactivity for two kinds of colon cancer cell line (Colo205 and HT29) were picked up for the purpose of obtaining a colon cancer specific high clone. Furthermore, according to a cDNA lambda phage system, a cDNA library was made from RNA extracted from HT29 and Colo205. However, a determination of positive well was difficult because of high antigenicity of coli in reactivity of T cell. Effective screening methods were considered, but data with reproducibility were not presented.Therefore when immunoresponsiveness with patient tumor tissue was investigated using lymphocyte from the cancer bearing patient who obtained informed consent, specific immunotherapy was not analyzed, and likelihood of further reinforcement of non-specific immunotherapy was investigated. The dendritic cell which was antigen presenting cell was generated from peripheral blood monocyte of the patient in one-step culture by using haemolytic streptococcus preparation(OK-432).