Research Project Pancreatic Cancer

项目 2（胰腺）总结 胰腺导管腺癌（PDAC）患者的预后很差。不幸的是，尝试 迄今为止，PDAC 的免疫疗法尚未取得显着的临床益处。人们普遍认为 放射治疗（RT）可以通过释放肿瘤源性抗原和危险信号来启动抗肿瘤免疫， 这种免疫启动效应对于多种癌症类型的放疗疗效起着至关重要的作用。相比之下，结合 放疗联合检查点免疫疗法在 PDAC 中通常效果不佳。目前还不清楚这是否反映了 放疗无法启动肿瘤特异性 T 细胞或需要额外的刺激剂来支持 T 细胞 启动。树突状细胞 (cDC) 是产生肿瘤抗原特异性 T 细胞反应的核心。在动物中 模型和人类相关研究表明，CDC 对于检查点免疫疗法的反应至关重要 RT 诱导的肿瘤免疫。我们的假设是放疗对局部和全身肿瘤产生不同的影响 通过对疾控中心的监管来获得豁免。我们将直接解决这个假设，重点关注 DC 和 T 细胞反应在 SOC RT 期间是共同形成的。我们将使用 scRNAseq、空间分辨的组合 人类 PDAC 组织和小鼠模型中的蛋白质、代谢组学分析，以测试以下内容。在目标 1 中，我们将 确定放疗对 cDC 局部免疫启动的局部和全身影响。这些研究将使用 从接受 SBRT 的患者身上纵向收集的人体组织与遗传基因相结合 工程小鼠模型 (GEMM) 评估 RT 对 DC 表型和功能的影响。利用我们的 机构优势，我们将在三组前瞻性和回顾性组织中进行这些研究 收集接受 SBRT 的人类 PDAC 患者，并使用 PDAC GEMM 进行机制研究。 这些研究将评估 SBRT 对 cDC 功能的局部影响。在目标 2 中，我们将确定以下因素的影响： RT 对 PDAC 患者 cDC 分化和全身免疫的影响。我们在人类 PDAC 患者和 小鼠模型表明，PDAC 中骨髓生成和 cDC 发育的关键差异可能会损害 肿瘤免疫。此外，我们的初步数据表明 SBRT 可以改变 cDC 的发育和 表型。为了这个目标，我们将结合人体组织和 GEMM 来专门研究 RTs 如何 影响系统性 DC 发育、表型和功能，以及这对肿瘤免疫和功能的净影响 RT 反应中的 T 细胞启动。在目标 3 中，我们将确定 RT 对区域间互动的影响 代谢和 cDC 导向的 T 细胞免疫。放疗可以对肿瘤和基质细胞产生巨大影响 新陈代谢。同时，这些代谢变化可以调节 cDC 和 T 细胞的存活和功能。然而， 这些相互作用尚未在完整的 PDAC 组织中得到充分研究，其中区域异质性 在免疫浸润中，缺氧和基质密度是主导因素。因此，我们将使用多个正交 包括 CODEX、NIMS 和人类 PDAC 组织的高级成像在内的方法可在空间上解决 SBRT 对细胞免疫、基质成分和代谢特征的次区域异质性的影响。

PROJECT 2 (PANCREAS) SUMMARY The prognosis for pancreatic ductal adenocarcinomas (PDAC) patients is dismal. Unfortunately, attempts at immunotherapy for PDAC to date have not achieved significant clinical benefits. It is widely accepted that radiation therapy (RT) can prime anti-tumor immunity by releasing tumor-derived antigens and danger signals, and this immune priming effect has a crucial role in RT efficacy in multiple cancer types. In contrast, combining RT with checkpoint immunotherapy has been generally underwhelming in PDAC. It is unclear if this reflects an inability of RT to prime tumor-specific T cells or a need for additional stimulants that are supportive of T-cell priming. Dendritic cells (cDCs) are central for generating tumor antigen-specific T-cell responses. In animal models and human correlative studies, cDCs are crucial for responsiveness to checkpoint immunotherapy and RT-induced tumor immunity. Our hypothesis is that RT drives divergent effects on local and systemic tumor immunities through regulation of cDCs. We will directly address this hypothesis, focusing on how DCs and T-cell responses are co-shaped during SOC RT. We will use a combination of scRNAseq, spatially resolved protein, metabolomic profiling in human PDAC tissues and mouse models to test the following. In Aim 1, we will determine the local and systemic impacts of RT on local immune priming by cDCs. These studies will use a combination of longitudinally collected human tissues from patients undergoing SBRT and genetically engineered mouse models (GEMMs) to assess the impact of RT on DC phenotype and function. Leveraging our institutional strengths, we will conduct these studies in three cohorts of prospective and retrospective tissue collections from human PDAC patients receiving SBRT and conduct mechanistic studies using PDAC GEMMs. These studies will assess the local impact of SBRT on cDC function. In Aim 2, we will determine the impact of RT on cDC differentiation and systemic immunity in PDAC patients. Our data in both human PDAC patients and mouse models demonstrated that key differences in myelopoiesis and cDC development in PDAC can impair tumor immunity. Furthermore, our preliminary data indicated that SBRT could alter cDC development and phenotype. In this aim, we will use a combination of human tissues and GEMMs to specifically study how RTs impact systemic DC development, phenotype and function, and the net impact this has on tumor immunity and T-cell priming in response to RT. In Aim 3, we will determine the impact of RT on interactions between regional metabolism and cDC-directed T-cell immunity. RT can have a dramatic impact on tumor and stromal cell metabolism. In parallel, these metabolic changes can regulate cDC and T-cell survival and function. However, these interactions have not been well studied in the context of intact PDAC tissues, where regional heterogeneity in immune infiltrate, hypoxia, and stromal density are dominant players. We will therefore use multiple orthogonal approaches including CODEX, NIMS, and advanced imaging of human PDAC tissues to spatially resolve the impact of SBRT on subregional heterogeneities in cellular immunity, stromal composition, and metabolic profiles.