Preclinical development of breakthrough immunotherapy for brain tumors

摘要 脑恶性肿瘤（如恶性胶质瘤）免疫治疗的最终成功将需要 将对免疫学的深入理解与以下长期挑战的解决方案相结合： 1)神经胶质瘤特异性抗原的缺乏和异质性表达; 2）神经胶质瘤特异性抗原的归巢和持续性差; 效应细胞毒性T淋巴细胞（CTL）;和3）神经胶质瘤诱导的免疫抑制。我的实验室 为这些领域的关键发现做出贡献，并将我们的发现整合到新型免疫疗法中 神经胶质瘤患者的临床试验。在目前的建议中，我们将利用我们目前的研究方向， 结合我们在神经胶质瘤抗原方面的专业知识和临床前细胞工程技术， 问题研究我们假设新的细胞工程和抗原靶向方法的整合 将使我们能够开发更安全，更有效的免疫治疗策略， 抗原的异质性表达和脑免疫学中的独特挑战。我们将评估 以下策略：1.用于安全有效免疫治疗的新型胶质瘤新抗原。我们将利用 我们目前的NINDS奖项（R 01 NS 096954和R21 NS 093654）和表征T细胞受体（TCR） 特异于源自儿童和成人神经胶质瘤的新抗原。2.序贯嵌合抗原 受体（CAR）/TCR系统。作为一种安全靶向神经胶质瘤相关 在不损害脑外正常细胞的情况下， 评估新的顺序合成Notch（synNotch）CAR/TCR系统，其中抗原信号传导 通过针对肿瘤特异性抗原的第一CAR或TCR诱导第二抗GAA CAR/TCR， 触发肿瘤部位的CTL活性。3.通过建立三级免疫系统靶向胶质瘤免疫环境 淋巴器官（TLO）。淋巴器官和专职抗原呈递细胞的缺乏是 这被认为是大脑免疫反应不足的主要原因。我们将评估诱导是否 脑肿瘤部位的TLO将促进有效和持久的胶质瘤抗原特异性免疫 脑肿瘤部位的反应。这三种策略将在逻辑上整合为组合方法。 新的抗原和TCR将被采用到synNotch CAR/TCR系统中，并且TLO方法将 当与synNotch CAR/TCR系统组合时也是最有益的。正如预期的那样， NINDS R35机制，这些策略可能涉及高风险。然而，根据我们的原理证明， 初步数据，我们将在R35机制的长期支持下坚持不懈地追求我们的目标， 灵活、快速地采用新技术。这些研究还将与正在进行的其他领域相结合。 我们实验室的研究。例如，溶瘤病毒介导的靶抗原的表达和CTL-吸引作用可以在细胞内进行。 趋化因子（“有效载荷”方法）将帮助我们克服趋化因子的缺乏和异质表达， 抗原以及CTL向胶质瘤组织的肿瘤归巢。R35将允许这些集成。

ABSTRACT The ultimate success of immunotherapy for brain malignancies, such as malignant glioma, will require integration of in-depth understanding of immunology with solutions for the following long-standing challenges: 1) paucity and heterogeneous expression of glioma-specific antigens; 2) poor homing and persistence of effector cytotoxic T lymphocytes (CTLs); and 3) glioma-induced immunosuppression. My laboratory has been contributing to critical discoveries in each of these areas, and integrated our findings into novel immunotherapy clinical trials for glioma patients. In the current proposal, we will leverage our current research directions by combining our expertise on glioma antigens and cutting-edge cell-engineering technologies in preclinical studies. We hypothesize that integration of novel cell-engineering and antigen-targeting approaches will allow us to develop safer and more effective immunotherapy strategies by overcoming heterogeneous expression of antigens and unique challenges in brain immunology. We will evaluate the following strategies: 1. Novel glioma neoantigens for safe and effective immunotherapy. We will leverage our current NINDS awards (R01NS096954 and R21NS093654) and characterize T-cell receptors (TCRs) specific to neoantigens derived from both pediatric and adult gliomas. 2. Sequential chimeric antigen receptor (CAR)/TCR system for targeting multiple antigens. As a way to safely target glioma-associated antigens (GAAs) in the tumor microenvironment without damaging normal cells outside of the brain, we will evaluate the novel sequential Synthetic Notch (synNotch) CAR/TCR system, in which antigen signaling through the first CAR or TCR against a tumor-specific antigen induces the second, anti-GAA CAR/TCR to trigger the CTL activity at the tumor site. 3. Targeting the glioma immune environment by creating tertiary lymphoid organs (TLOs). The absence of lymphatic organs and professional antigen presenting cells are thought to be major reasons for insufficient immune responses in the brain. We will evaluate whether induction of TLOs in the brain tumor site will facilitate efficient and long-lasting glioma antigen-specific immune responses in the brain tumor site. These 3 strategies will be logically integrated into combination approaches. Novel antigens and TCRs will be adopted into the synNotch CAR/TCR system, and the TLO approach would also be most beneficial when combined with the synNotch CAR/TCR system. As expected per the purpose of the NINDS R35 mechanism, these strategies may involve high risks. However, based on our proof-of-principle preliminary data, we will persistently pursue our goals with the long-term support by the R35 mechanism, and flexibly and swiftly adopt new technologies. These studies will also integrate with other areas of ongoing studies in our lab. For example, oncolytic virus-mediated expression of target antigen and CTL-attracting chemokine (“payload” approaches) would help us to overcome the paucity and heterogeneous expression of antigens as well as tumor homing of CTLs to the glioma tissue. The R35 would allow these integrations.