Tajima Kouhei, Ito Yoshinori, Demachi Ayako, Nishida Keiko, Akatsuka Yoshiki, Tsujimura Kunio, Hida Toyoaki, Morishima Yasuo, Kuwano Hiroyuki, Mitsudomi Tetsuya, Takahashi Toshitada, Kuzushima Kiyotaka
Division of Immunology, Aichi Cancer Center Research Institute, Nagoya, Japan.
Int J Cancer. 2004 Jun 20;110(3):403-12. doi: 10.1002/ijc.20139.
There is accumulating evidence that peptides derived from the catalytic subunit of human telomerase reverse transcriptase (hTERT) are specifically recognized by CD8+ cytotoxic T lymphocytes. We investigated the cytotoxicity of a human leukocyte antigen (HLA)-A*2402-restricted hTERT-derived peptide 461-469 (hTERT461)-specific CD8+ T-cell clone, designated as K3-1, established from a healthy donor by repetitive peptide stimulation. This clone exhibited cytotoxicity against 4 out of 6 HLA-A24-positive lung cancer cell lines with positive telomerase activity but not 4 HLA-A24-negative examples. When the target cells were pretreated with 100 U/ml of interferon (IFN)-gamma for 48 hr, the susceptibility to K3-1 increased with PC9 cells but unexpectedly decreased with LU99 cells. However, in both cell lines, the expression of molecules associated with epitope presentation such as HLA-A24, transporters associated with antigen processing, low molecular weight polypeptide 7 and proteasome activator 28 was similarly increased after IFN-gamma treatment. Results of CTL assays using acid-extracted peptides indicated that the epitope increased on PC9 cells but not on LU99 cells after IFN-gamma treatment. Semi-quantitative reverse transcriptase polymerase chain reaction disclosed that the expression of hTERT was attenuated in LU99 but not in PC9 cells, accounting for the decreased cytotoxicity mediated by K3-1. The attenuation of the hTERT expression and K3-1-mediated cell lysis after IFN-gamma treatment was also observed in primary adenocarcinoma cells obtained from pulmonary fluid of a lung cancer patient. Our data underline the utility of peptide hTERT461 in immunotherapy for lung cancer, as with other malignancies reported earlier, and suggest that modulation of hTERT expression by IFN-gamma needs to be taken into account in therapeutic approach.
越来越多的证据表明，人端粒酶逆转录酶（hTERT）催化亚基衍生的肽段能被CD8 + 细胞毒性T淋巴细胞特异性识别。我们研究了一种人白细胞抗原（HLA）-A*2402限制性的hTERT衍生肽461 - 469（hTERT461）特异性CD8 + T细胞克隆（命名为K3 - 1）的细胞毒性，该克隆是通过重复肽刺激从一名健康供体中建立的。该克隆对6株具有端粒酶活性的HLA - A24阳性肺癌细胞系中的4株表现出细胞毒性，但对4株HLA - A24阴性的肺癌细胞系无细胞毒性。当靶细胞用100 U/ml的干扰素（IFN）-γ预处理48小时后，PC9细胞对K3 - 1的敏感性增加，但出乎意料的是，LU99细胞的敏感性降低。然而，在这两种细胞系中，IFN - γ处理后，与表位呈递相关的分子如HLA - A24、抗原加工相关转运体、低分子量多肽7和蛋白酶体激活剂28的表达同样增加。使用酸提取肽进行的细胞毒性T淋巴细胞（CTL）检测结果表明，IFN - γ处理后，PC9细胞上的表位增加，而LU99细胞上的表位未增加。半定量逆转录酶聚合酶链反应显示，hTERT的表达在LU99细胞中减弱，但在PC9细胞中未减弱，这解释了K3 - 1介导的细胞毒性降低的原因。在从一名肺癌患者的肺液中获得的原发性腺癌细胞中也观察到IFN - γ处理后hTERT表达的减弱和K3 - 1介导的细胞裂解。我们的数据强调了肽hTERT461在肺癌免疫治疗中的效用，正如早期报道的其他恶性肿瘤一样，并表明在治疗方法中需要考虑IFN - γ对hTERT表达的调节作用。
