Local control of anti-tumor/anti-self reactivity in low-affinity ACT

 描述（由申请人提供）：基于美国国家癌症研究所（NCI）和美国国家过敏和传染病研究所（NIAID）支持的校内和校外研究的努力，采用肿瘤浸润和受体工程化T细胞的癌症和慢性病毒感染的过继细胞治疗（ACT）已从实验环境转向日益增加的临床现实。尽管高亲和力T细胞的转移对于各种肿瘤类型具有很大的希望，但它们的超生理亲和力和抗原敏感性可对共享靶抗原表达的自身组织造成显著的“中靶”免疫病理损伤。扩大ACT可治疗肿瘤的疗效和范围的一个关键目标将通过设计控制抗肿瘤和抗自身免疫之间的平衡以有利于前者的方法来实现。该探索性项目的目标是确定表达中等亲和力受体的CD 8 + T细胞是否可以通过对其肿瘤微环境的免疫操作来诱导特异性根除肿瘤，而不会对不存在这种改变的健康自身组织造成自身免疫损伤。这项工作将在卵巢癌（ID 8）的鼠模型中进行，其特征在于RIP-mOVA小鼠中胰腺和肾脏共享模型抗原的表达。ACT将在携带ID 8肿瘤的RIP-mOVA小鼠中使用对共享抗原具有特异性的中等亲和力OT-3 CD 8 + T细胞进行，这些细胞反映了人类中的耐受后组库，因为它们已经经历了阴性选择并且仍然不知道其同源外周抗原，除非它们被特异性地引发。目的：我将定义肿瘤控制与中亲和力CD 8 + T细胞的靶向自身免疫的治疗参数，工作假设是对肿瘤和自身的反应性阈值是紧密耦合的。这些实验将检查细胞数量和引发刺激在诱导β胰岛的肿瘤控制与自身免疫破坏中的作用。目的II将评估肿瘤微环境的改变是否可以允许低于自身免疫阈值的OT-3细胞选择性地识别治疗的和远端的肿瘤，工作假设局部免疫调节可以通过中等亲和力T细胞打开肿瘤控制的机会窗口。在这方面待测试的修饰包括A）去除抑制性细胞类型（调节性T细胞，2型巨噬细胞，髓源性抑制细胞）或信号（TGF-β、IL-6、IL-10、PD-1/L1和CTLA-4），B）用肿瘤内免疫刺激细胞因子增强局部OT-3活化在一些实施方案中，本发明涉及通过肿瘤内注射CXCR 3趋化因子（CXCL 9/10）增加OT-3细胞的局部归巢和滞留（IL-2、IL-12）或共刺激信号（CD 27、4-1BB、CD 40），和C）通过肿瘤内注射CXCR 3趋化因子（CXCL 9/10）增加OT-3细胞的局部归巢和滞留。如果成功，该项目将支持一种新的范式，使ACT中使用的肿瘤特异性TCR的库大大扩展，并将大大减少靶向毒性的发生，这些毒性限制了其在更广泛的肿瘤类型中的应用。

 DESCRIPTION (provided by applicant): Based significantly on the efforts of both intramural and extramural research supported by the National Cancer Institute (NCI) and the National Institutes of Allergy and Infectious Disease (NIAID), adoptive cellular therapy (ACT) of cancer and chronic viral infections with tumor-infiltrating and receptor-engineered T cells has moved from experimental setting to one of increasing clinical reality. Although transfer of high-affinityT cells holds great promise for a variety of tumor types, their supraphysiologic affinities and antigen sensitivity can cause significant "on-target" immunpathologic damage to self-tissues that share expression of the targeted antigen. A key goal for expanding the efficacy and range of tumors treatable by ACT would be realized by devising ways of controlling the balance between anti-tumor and anti-self-immunity to favor the former. The goal of this exploratory project is to determine whether CD8+ T cells expressing moderate-affinity receptors can be induced to specifically eradicate tumors through immunologic manipulation of their tumor microenvironment without autoimmune damage to healthy self-tissues where such alterations are absent. This work will be carried out in a murine model of ovarian carcinoma (ID8) which features shared expression of a model antigen with both pancreas and kidney in RIP-mOVA mice. ACT will be performed in ID8 tumor-bearing RIP-mOVA mice using moderate affinity OT-3 CD8+ T cells specific for the shared antigen that mirror the post-tolerant repertoire in humans in that they have undergone negative selection and remain ignorant of their cognate peripheral antigen unless they are specifically primed to do so. Aim I will define the therapeutic parameters of tumor control versus on-target autoimmunity by moderate-affinity CD8+ T cells, with the working hypothesis that the threshold for reactivity to both tumor and self is closely coupled. These experiments will examine the role of cell number and priming stimulus in inducing tumor control versus autoimmune destruction of beta islets. Aim II will evaluate whether alterations of tumor microenvironment can allow a number OT-3 cells that is below the threshold for autoimmunity to selectively recognize treated and distal tumors, with the working hypothesis that local immunomodulation can open a window of opportunity for tumor control by moderate affinity T cells. Modifications to be tested in this regard include A) removing inhibitory cell types (regulatory T cells, type 2 macrophages, myeloid-derived suppressor cells) or signals (TGF-β, IL-6, IL-10, PD-1/L1, and CTLA-4), B) enhancing local OT-3 activation with intratumoral immunostimulatory cytokines (IL-2, IL-12) or costimulatory signals (CD27, 4-1BB, CD40), and C) increasing local homing and retention of OT-3 cells by intratumoral injection of CXCR3 chemokines (CXCL9/10). If successful, this project will support a new paradigm that will enable a greatly expanded repertoire of tumor-specific TCRs to be used in ACT, and will greatly decrease the occurrence of on-target toxicities that have limited its application to a broader range of tumor types.