Fundamental study for improvement of cancer immunotherapy based on gene analysis

我们正在使用自体癌症特异性细胞毒性T淋巴细胞（ctl）进行过继免疫治疗。在本临床试验中，将晚期癌症患者外周血单核细胞（PBMC）在IL-2 （100U/ml）和患者辐照肿瘤细胞的作用下培养约14天。培养后，在大多数PBMC中识别出NK细胞和LAK细胞等主要ctl。此外，我们正在使用CTL前体靶向癌症疫苗对晚期或复发癌症患者进行I/II期试验。对于从这些患者身上获得的癌症样本，计划使用DNA尖端进行基因分析，以确定治疗前免疫治疗的有效病例。本研究共库存肿瘤样本2份，有效病例样本6份，无效病例样本5份。然而，在许多情况下，由于没有肿瘤病变或基因分析排斥，我们未能储存癌症样本。在调节性T细胞分析的基础研究中，培养14天以上的淋巴细胞中CD4+/CD25+ T细胞占主导地位。这些调节性t细胞通过抗il -2受体α抗体体外处理而减少。通过这种处理，TGF-β的产生也减少了。我们进一步对蛋白酶体抑制剂（PI）进行基础研究，以提高肿瘤免疫治疗的效果。通过PI处理TRAIL受体弱表达的癌细胞，TRAIL受体明显表达，TRAIL活性明显提高。从这些结果来看，我们必须控制调节性t细胞和TRAIL活性，以提高癌症免疫治疗的临床效果。进一步，我们将继续进行肿瘤样本的储存，以研究DNA尖端的基因分析。

We are performing adoptive immunotherapy using autologous cancer specific cytotoxic T lymphocytes (CTLs). In this clinical trial, peripheral blood mononuclear cells (PBMC) obtained from advanced cancer patient were cultured for about 14 days under the addition of IL-2 (100U/ml) and patient's irradiated tumor cells. Following the cultivation, predominant CTLs including NK cells and LAK cells were recognized in most PBMC. Further more, we are performing phase I/II trial for advanced or recurrent cancer patients using CTL precursor-oriented cancer vaccine. For cancer samples obtained from these patients, gene analysis using DNA tip was planned to define effective cases of immunotherapy prior to treatment. In this study, II cancer samples were stocked, 6 were effective case samples and 5 were non effective case samples. However we have failed to stock cancer samples in many cases due to no tumor lesion or rejection of gene analysis.In the fundamental studies on regulatory T cell analysis, CD4+/CD25+ T-cells were dominant in cultured lymphocytes more than 14 days. These regulatory T-cells were reduced by in vitro treatment of anti-IL-2 receptor α antibody. By this treatment, production of TGF-β was also reduced. We performed further fundamental study on proteasome inhibitor (PI) to improve the effect of cancer immunotherapy. By the PI treatment of cancer cells with weak expression of TRAIL receptor, TRAIL receptor was markedly expressed and TRAIL activity was significantly improved.From these results, we have to control regulatory T-cell and TRAIL activity to improve the clinical effect of cancer immunotherapy. Further we will continue the storage of cancer samples to investigate gene analysis by DNA tip.