Komori Hiroyuki, Nakatsura Tetsuya, Senju Satoru, Yoshitake Yoshihiro, Motomura Yutaka, Ikuta Yoshiaki, Fukuma Daiki, Yokomine Kazunori, Harao Michiko, Beppu Toru, Matsui Masanori, Torigoe Toshihiko, Sato Noriyuki, Baba Hideo, Nishimura Yasuharu
Department of Immunogenetics, Graduate School of Medical Sciences, Kumamoto University, Honjo, Japan.
Clin Cancer Res. 2006 May 1;12(9):2689-97. doi: 10.1158/1078-0432.CCR-05-2267.
We previously reported that glypican-3 (GPC3) was overexpressed, specifically in hepatocellular carcinoma (HCC) and melanoma in humans, and it was useful as a novel tumor marker. We also reported that the preimmunization of BALB/c mice with dendritic cells pulsed with the H-2K(d)-restricted mouse GPC3(298-306) (EYILSLEEL) peptide prevented the growth of tumor-expressing mouse GPC3. Because of similarities in the peptide binding motifs between H-2K(d) and HLA-A24 (A2402), the GPC3(298-306) peptide therefore seemed to be useful for the immunotherapy of HLA-A24+ patients with HCC and melanoma. In this report, we investigated whether the GPC3(298-306) peptide could induce GPC3-reactive CTLs from the peripheral blood mononuclear cells (PBMC) of HLA-A24 (A2402)+ HCC patients. In addition, we used HLA-A2.1 (HHD) transgenic mice to identify the HLA-A2 (A*0201)-restricted GPC3 epitopes to expand the applications of GPC3-based immunotherapy to the HLA-A2+ HCC patients.
We found that the GPC3(144-152) (FVGEFFTDV) peptide could induce peptide-reactive CTLs in HLA-A2.1 (HHD) transgenic mice without inducing autoimmunity. In five out of eight HLA-A2+ GPC3+ HCC patients, the GPC3(144-152) peptide-reactive CTLs were generated from PBMCs by in vitro stimulation with the peptide and the GPC3(298-306) peptide-reactive CTLs were also generated from PBMCs in four of six HLA-A24+ GPC3+ HCC patients. The inoculation of these CTLs reduced the human HCC tumor mass implanted into nonobese diabetic/severe combined immunodeficiency mice.
Our study raises the possibility that these GPC3 peptides may therefore be applicable to cancer immunotherapy for a large number of HCC patients.
我们之前报道过，磷脂酰肌醇蛋白聚糖-3（GPC3）在人类肝细胞癌（HCC）和黑色素瘤中过度表达，可作为一种新型肿瘤标志物。我们还报道过，用H-2K(d)限制性小鼠GPC3(298 - 306)（EYILSLEEL）肽脉冲处理的树突状细胞对BALB/c小鼠进行预免疫，可抑制表达小鼠GPC3的肿瘤生长。由于H-2K(d)和HLA-A24（A2402）之间的肽结合基序存在相似性，因此GPC3(298 - 306)肽似乎对HLA-A24+的HCC和黑色素瘤患者的免疫治疗有用。在本报告中，我们研究了GPC3(298 - 306)肽是否能从HLA-A24（A2402）+的HCC患者外周血单个核细胞（PBMC）中诱导出GPC3反应性细胞毒性T淋巴细胞（CTL）。此外，我们使用HLA-A2.1（HHD）转基因小鼠来鉴定HLA-A2（A*0201）限制性GPC3表位，以将基于GPC3的免疫治疗应用扩展到HLA-A2+的HCC患者。
我们发现GPC3(144 - 152)（FVGEFFTDV）肽能在HLA-A2.1（HHD）转基因小鼠中诱导肽反应性CTL，且不诱导自身免疫。在8例HLA-A2+ GPC3+的HCC患者中，有5例通过用该肽进行体外刺激，从PBMC中产生了GPC3(144 - 152)肽反应性CTL；在6例HLA-A24+ GPC3+的HCC患者中，有4例也从PBMC中产生了GPC3(298 - 306)肽反应性CTL。接种这些CTL可减少植入非肥胖糖尿病/严重联合免疫缺陷小鼠体内的人HCC肿瘤块。
我们的研究提出了这些GPC3肽可能适用于大量HCC患者癌症免疫治疗的可能性。
