Tumor microenvironment: Impact on T cell tumor-targeting, activation and survival

描述（由申请人提供）：异常的肿瘤微环境可损害T细胞功能并限制免疫应答。肿瘤来源的乳酸盐和酸性微环境，以及肿瘤/基质分泌的TGF β可以独立地和协同地抑制T细胞增殖、细胞因子产生和细胞毒性。我们建议改变肿瘤微环境的组分（pH、乳酸盐和TGF？），并在两种具有原位、肺和骨肿瘤生长的高度侵袭性、免疫活性的前列腺癌动物模型中评估这些对PSMA嵌合抗原受体（CAR）特异性T细胞治疗的影响。我们的中心主题和假设是，一个显着异常的肿瘤微环境影响T细胞肿瘤靶向和生存，以及T细胞活化，增殖和效应功能，这些T细胞功能可以使用新的双报告系统进行监测。组成型报告基因将用于对T细胞运输、肿瘤靶向和存活进行成像，诱导型报告基因系统将同时对T细胞功能进行成像和评估。一个诱导型报告基因将监测通过PSMA特异性CAR介导的T细胞活化;另一个将监测T细胞中的TGF β信号传导。将使用多模态成像技术评估肿瘤微环境中遗传诱导的异常（低pHe、高乳酸盐和高TGF？）对T细胞运输和功能的影响。在同一只动物中，将使用MRI重复评估肿瘤微环境的状态，以测量pHe和乳酸盐，并使用microPET评估肿瘤生长期间和过继性T细胞治疗期间的肿瘤缺氧。额外的离体免疫组织化学细胞测定将独立评估肿瘤微环境并确认T细胞状态。我们还预计，使用药物干预使肿瘤微环境的不同组分（pHe、乳酸盐和TGF β）"正常化"将显著增强T细胞治疗;因此，我们纳入了治疗子目标来测试这一假设。这些研究的相关性和影响是：1）肿瘤微环境中的乳酸盐，pHe和TGF水平经常异常，特别是在更具侵袭性的肿瘤中，并且与免疫反应降低有关。2)重要的是，存在特定的治疗方式来“正常化”这些组件，他们将进行调查。3)本项目中开发和使用的许多成像策略（例如，MRSI测量pHe和乳酸）可以转化为临床研究，其中可以使用人类报告基因和PET成像监测患者中的T细胞运输和功能，并且可以更全面地评估过继性T细胞治疗策略。 公共卫生相关性：异常的微环境是侵袭性前列腺癌的特征，并且与对肿瘤的免疫反应降低有关;因此，我们建议研究肿瘤微环境中特定异常对免疫系统的影响。我们预计，“正常化”肿瘤微环境中的这些异常将显着改善对免疫疗法的治疗反应。该建议中开发的成像策略和治疗对策可应用于前列腺癌患者，并可作为其他癌症和干细胞治疗的类似研究的模型。

DESCRIPTION (provided by applicant): An abnormal tumor microenvironment can impair T cell function and limit the immune response. Tumor- derived lactate and an acidic microenvironment, as well as tumor/stromal secretion of TGF¿ can independently and synergistically suppress T cell proliferation, cytokine production and cytotoxicity. We propose to alter components of the tumor microenvironment (pHe, lactate and TGF¿) and assess these effects on PSMA chimeric antigen receptor (CAR) specific T cell therapy in two highly aggressive, immunocompetent animal models of prostate cancer with orthotopic, lung and bone tumor growth. Our central theme and hypothesis is that a markedly abnormal tumor microenvironment affects T cell tumor-targeting and survival, as well as T cell activation, proliferation and effector-function, and that these T cell functions can be monitored using novel dual reporter systems. A constitutive-reporter will be used for imaging T cell trafficking, tumor targeting and survival, and inducible-reporter systems will concurrently image and assess T cell function. One inducible reporter will monitor T cell activation mediated through a PSMA- specific CAR; the other will monitor TGF¿-signaling in T cells. The effects of genetically induced abnormalities in the tumor microenvironment (low pHe, high lactate and high TGF¿) on T cell trafficking and function will be assessed using multimodality imaging techniques. The status of the tumor microenvironment will be assessed repeatedly in the same animal using MRIS to measure pHe and lactate, and microPET to assess tumor hypoxia during tumor growth and during adoptive T cell therapy. Additional ex vivo immunohistochemical cell assays will independently assess the tumor microenvironment and confirm T cell status. We also expect that "normalization" of different components of the tumor microenvironment (pHe, lactate and TGF¿) using pharmacological intervention will significantly enhance T cell therapy; therefore, we have included therapeutic sub-aims to test this hypothesis. The relevance and impact of these studies are that: 1) Lactate, pHe, and TGF¿ levels in the tumor microenvironment are frequently abnormal, particularly in more aggressive tumors, and are associated with a reduced immune response. 2) Importantly, there exist specific treatment modalities to "normalize" these components, and they will be investigated. 3) Many of the imaging strategies developed and used in this project (e.g., MRSI to measure pHe and lactate) could be translated to clinical studies, where monitoring T cell trafficking and function can be monitored in patients using human reporter genes and PET imaging, and where adoptive T cell treatment strategies could be more fully evaluated. PUBLIC HEALTH RELEVANCE: An abnormal microenvironment is characteristic of aggressive prostate cancer, and is associated with a reduced immune response to the tumor; therefore, we propose to study the effects of specific abnormalities in the tumor microenvironment on the immune system. We expect that "normalizing" these abnormalities in the tumor microenvironment will significantly improve the therapeutic response to immunotherapy. The imaging strategies and therapeutic counter-measures developed in this proposal could be applied to patients with prostate cancer, and could serve as a model for similar studies in other cancers and for stem cell therapy as well.