Optimization of CAR-Bacteria for Oral Cancer

摘要 本项目的目的是探索嵌合抗原受体（汽车）的产生的可行性 由细菌表达。我们建议探索细菌介导的想法和用途，而不是使用T细胞。 有针对性地摧毁癌细胞。此外，我们探索了我们可以靶向CAR细菌的可能性， 特异性主要组织相容性复合物（MHC）-新肽复合物（pMHC）。我们称这些 工程化细菌细胞CAR-细菌。目前表达CAR的T细胞提供了持久的应答，但 三个主要限制：特异性、毒性和可行性。本研究将解决所有这三个问题。在这 在该提案中，我们将工程化细菌裂解靶向表达HLA-A2-E7的头颈癌或宫颈癌细胞， 一种已知的人乳头瘤病毒（HPV）感染的肿瘤细胞上的pMHC。这种靶向作用使抗肿瘤蛋白 只有当达到预定的细菌种群密度时才能生产。这种方法应该戏剧性地 减少细菌菌落大小并大大降低/防止全身毒性。该方法有可能 作为HPV阳性口腔癌的治疗剂，因为它可以作为细菌漱口水施用和控制。 该项目结合了两项创新，利用经过验证的合成进化纳米抗体（SEN）库 能够选择性结合MHC-肽复合物并将这种特异性癌细胞靶向与 同步循环裂解以产生CAR细菌。我们提出的研究提供了概念验证，（1）汽车 可以产生识别pMHC的CAR，（2）CAR-细菌的定位和定植可以由肿瘤控制， （3）CAR-细菌对表达某些pMHC的肿瘤细胞具有治疗活性， 特异性pMHC。我们通过以下两个目标完成这些概念验证研究：（1）优化 CAR-细菌与HLA-A2-E7的结合和特异性，以及（2）检查CAR-细菌在动物模型中的功效 头颈部和宫颈癌的发病率。

ABSTRACT The goal of this project is to explore the feasibility of generating Chimeric Antigen Receptors (CARs) expressed by bacteria. Instead of using T cells, we propose to explore the idea and use of bacteria to mediate the targeted destruction of cancer cells. In addition, we explore the possibility that we could target CAR-bacteria to specific major histocompatibility complex (MHC)-neopeptide complexes (pMHC) on tumor cells. We call these engineered bacteria cells CAR-bacteria. Current CAR-expressing T cells provide durable responses but have three main limitations: specificity, toxicity, and feasibility. This study will address all three concerns. In this proposal, we target engineered bacterial lysis to head and neck or cervical cancer cells expressing HLA-A2-E7, a known pMHC on tumor cells infected by human papilloma virus (HPV). The targeting enables anti-tumor protein production only when a predefined population density of bacteria is reached. This method should dramatically reduce bacterial colony size and greatly lowers/prevents systemic toxicities. The approach has the potential to be a therapeutic in HPV-positive oral cancer as it could be administered and controlled as a bacterial mouthwash. This project combines two innovations leveraging a Synthetically-Evolved Nanobody (SEN) library proven capable of selectively binding MHC-peptide complexes and combining this specific cancer cell targeting with synchronized circuit lysis to create CAR-bacteria. Our proposed studies provide proof-of-concept that (1) CARs can be produced that recognize pMHC, (2) CAR-bacteria localization and colonization can be controlled by tumor expression of certain pMHC and (3) CAR-bacteria have therapeutic activity against tumor cells that express specific pMHC. We accomplish these proof-of-concept studies via the following two objectives: (1) Optimize binding and specificity of CAR-bacteria to HLA-A2-E7 and (2) Check efficacy of CAR-bacteria in an animal model of head and neck and cervical cancer.