Surgery Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Hum Gene Ther. 2012 Oct;23(10):1043-53. doi: 10.1089/hum.2012.041. Epub 2012 Sep 24.
No curative treatment exists for glioblastoma, with median survival times of less than 2 years from diagnosis. As an approach to develop immune-based therapies for glioblastoma, we sought to target antigens expressed in glioma stem cells (GSCs). GSCs have multiple properties that make them significantly more representative of glioma tumors than established glioma cell lines. Epidermal growth factor receptor variant III (EGFRvIII) is the result of a novel tumor-specific gene rearrangement that produces a unique protein expressed in approximately 30% of gliomas, and is an ideal target for immunotherapy. Using PCR primers spanning the EGFRvIII-specific deletion, we found that this tumor-specific gene is expressed in three of three GCS lines. Based on the sequence information of seven EGFRvIII-specific monoclonal antibodies (mAbs), we assembled chimeric antigen receptors (CARs) and evaluated the ability of CAR-engineered T cells to recognize EGFRvIII. Three of these anti-EGFRvIII CAR-engineered T cells produced the effector cytokine, interferon-γ, and lysed antigen-expressing target cells. We concentrated development on a CAR produced from human mAb 139, which specifically recognized GSC lines and glioma cell lines expressing mutant EGFRvIII, but not wild-type EGFR and did not recognize any normal human cell tested. Using the 139-based CAR, T cells from glioblastoma patients could be genetically engineered to recognize EGFRvIII-expressing tumors and could be expanded ex vivo to large numbers, and maintained their antitumor activity. Based on these observations, a γ-retroviral vector expressing this EGFRvIII CAR was produced for clinical application.
目前尚无治疗胶质母细胞瘤的方法，从诊断到中位生存时间不到 2 年。为了开发针对神经胶质瘤干细胞（GSCs）的免疫疗法，我们试图靶向 GSCs 中表达的抗原。GSCs 具有多种特性，使其比已建立的神经胶质瘤细胞系更能代表神经胶质瘤肿瘤。表皮生长因子受体变体 III（EGFRvIII）是一种新的肿瘤特异性基因重排的结果，产生一种独特的蛋白质，约 30%的神经胶质瘤表达，是免疫治疗的理想靶点。使用跨越 EGFRvIII 特异性缺失的 PCR 引物，我们发现该肿瘤特异性基因在三个 GCS 系中均有表达。基于七种 EGFRvIII 特异性单克隆抗体（mAbs）的序列信息，我们组装了嵌合抗原受体（CAR），并评估了 CAR 修饰的 T 细胞识别 EGFRvIII 的能力。其中三种抗 EGFRvIII CAR 修饰的 T 细胞产生了效应细胞因子干扰素-γ，并溶解了表达抗原的靶细胞。我们集中开发了一种来自人源 mAb 139 的 CAR，它特异性地识别表达突变型 EGFRvIII 的 GSC 系和神经胶质瘤细胞系，但不识别任何测试的正常人类细胞。使用基于 139 的 CAR，可以对胶质母细胞瘤患者的 T 细胞进行基因工程改造，以识别表达 EGFRvIII 的肿瘤，并在体外大量扩增，并保持其抗肿瘤活性。基于这些观察结果，生产了一种表达这种 EGFRvIII CAR 的γ-逆转录病毒载体，用于临床应用。
