Synthetic immunoreceptor systems for combinatorial tumor antigen detection

描述(申请人提供)：在过继免疫疗法中，从患者分离的免疫细胞可以植入合成蛋白质，使细胞能够执行治疗功能，如摧毁肿瘤细胞。其中一类是嵌合抗原受体(CARS)，它是细胞外单链抗体和细胞内信号域的融合。可定制的抗体部分可以结合到靶细胞表面上的特定抗原标记物。CAR的模块化细胞内信号部分然后在免疫细胞中启动反应。在癌症免疫治疗中，CAR介导的基于癌细胞上单个标记物的癌细胞识别和杀伤已被证明在临床上是有用的。然而，最近的研究也揭示了安全方面的一个重大陷阱： 肿瘤细胞上高度丰富的标记物在一些正常细胞上也可能存在较低的丰度。车载免疫细胞无意中杀死了这样的正常细胞，导致了患者的严重毒性甚至死亡。该项目计划实现以下目标 目标：(1)开发基于标记组合而不是单一标记来调节免疫细胞功能的CAR系统。预期的结果是，只有具有特定表面标志组合的癌细胞才会被免疫细胞杀死。这一原则验证项目旨在为更复杂的CAR系统的设计提供有价值的见解，并提高合成蛋白受体在细胞免疫疗法中的临床实用价值。(2)比较在过继免疫治疗中有用的两种主要免疫细胞T细胞和自然杀伤细胞中CAR系统的特性。研究表明，由于免疫细胞内的先天差异，CAR可以在不同的细胞类型中表现出不同的功能特性。因此，确定CARS和CAR系统在不同免疫细胞类型中的特征对于丰富目前对分子和细胞免疫学的理解并确定CARS的临床应用范围具有重要意义。通过追求拟议的研究目标，我希望获得生物工程、癌症生物学和免疫学方面的专业知识。所获得的知识和技能将为我在合成生物学和癌症免疫学方面的独立职业生涯做好准备。 公共卫生相关性：在癌症的过继免疫疗法中，可以将合成蛋白质植入患者自身的免疫细胞，使其能够摧毁患者体内的肿瘤。然而，最近的临床试验发现了一个陷阱--对体内癌症和正常细胞的区分不足，导致免疫细胞对正常细胞的不受欢迎的杀伤和严重的毒性。该项目的目标是设计基于合成蛋白质的系统，以提高免疫细胞对癌细胞的识别能力，并丰富目前对免疫细胞中分子信号机制的了解。

DESCRIPTION (provided by applicant): In adoptive immunotherapy, immune cells isolated from patients can be engrafted with synthetic proteins that enable the cells to perform therapeutic functions, such as destroying tumor cells. One class of these proteins is the chimeric antigen receptors (CARs), which are fusions of extracellular single chain antibodies and intracellular signaling domains. The customizable antibody portion can bind to a specific antigen marker on a target cell surface. The modular intracellular signaling portion of the CAR then initiates a response in the immune cell. In cancer immunotherapy, CAR-mediated recognition and killing of cancer cells based on a single marker on the cancer cell has been shown to be clinically useful. However, recent studies also reveal a significant pitfall in safety: markers that are highly abundant on tumor cells can also be present at lower abundance on some normal cells. Unintentional killing of such normal cells by CAR-carrying immune cells has led to severe toxicity or even death of the patient. This project proposes to achieve the following goals: (1) Develop CAR systems that mediate immune cell functions based on combinations of markers instead of single markers. The intended result is that only cancer cells with a specific combination of surface markers will be killed by the immune cell. This proof-of-principle project is envisioned to generate valuable insights into the designs of more sophisticated CAR systems and to improve clinical utility of synthetic protein receptors in cell- based immunotherapy. (2) Compare the properties of the developed CAR systems in both T cells and Natural Killer cells, two major types of immune cells that are therapeutically useful in adoptive immunotherapy. Studies have shown that due to innate differences within the immune cells, a CAR can manifest different functional properties in different cell types. Characterizing CARs and CAR systems in different immune cell types is therefore important for enriching the current understanding of molecular and cellular immunology while defining the range of clinical utility of CARs. By pursuing the proposed research goals, I expect to gain expertise in bio-engineering, cancer biology and immunology. The acquired knowledge and skills will prepare me for an independent career in synthetic biology and cancer immunology. PUBLIC HEALTH RELEVANCE: In adoptive immunotherapy for cancer, a patient's own immune cells can be engrafted with synthetic proteins so that the cells are capable of destroying tumors in the patient. However recent clinical trials revealed a pitfall - insufficient discriminaton between cancer and normal cells in the body, leading to undesirable killing of normal cells by the immune cells and severe toxicity. The goal of this project is to design synthetic protein-based systems that will improve immune cells' recognition of cancer cells and to enrich the current understanding of molecular signaling mechanisms in immune cells.