Modulation of the human pancreatic microenvironment by combined cytokine and immune checkpoint blockade

项目总结 胰腺导管腺癌(PDAC)具有明显的免疫屏障抑制作用。一个值得注意的因素 是由癌症相关成纤维细胞(CAF)亚群驱动的纤维化间质。另一种是髓系偏斜 PDAC肿瘤中TIL的免疫成分，缺乏强大的效应性T细胞浸润。我们假定 白介素6(IL-6)是促进炎性CAF、抑制髓系细胞的关键因子 居住，并伴有PDAC的T细胞功能障碍。使用创新的翻译方法和患者 标本，我们将探讨转移瘤中IL-6、CAF与髓系细胞和T细胞平衡的关系。 人类PDAC。临床前模型的研究支持这些因素在原发和转移中的作用 PDAC肿瘤，我们的工作将通过研究肿瘤和患者的血液样本来促进进一步的发现 其中，关键的细胞因子介质IL-6与PD-1免疫检查点一起被阻断。这一数据将增强 我们对CAF如何与转移灶中的细胞因子和免疫细胞相互作用的理解。这项建议 阐述了IL-6直接作用于CAF和免疫细胞是 在转移性PDAC中维持免疫“冷”的肿瘤微环境(TME)，并有助于 免疫治疗耐药。我们将测试我们的总体假设，即IL-6抑制对PDAC的免疫， 通过它对CAF和免疫细胞的影响，以及它的靶向，重新编程TME以增强 免疫治疗的疗效。我们小组以前的出版物已经证明了IL-6在PDAC和 在小鼠模型中显示了靶向它如何提高免疫检查点阻断的效率。这些广泛的 这项提议的努力已经达到顶峰，它将转化为患者对IL-6和PD-1的首次人体试验 封锁PDAC。这项试验提供了一项关于IL-6和CAF如何与免疫平衡相关的必要研究 转移瘤中的细胞。这项提议是一个重要的机会来揭示 CAF、免疫细胞和IL-6在转移性疾病中的作用我们将实现两个具体目标。首先，我们将 确定IL-6和PD-1的双重阻断如何协调肿瘤中CAF群体的平衡 转移性PDAC患者。在这个目标中，我们将使用来自配对的预编码的人类样本来生成基础数据 以及来自临床试验的PDAC转移的治疗活组织检查。CAF的组成将通过以下方式测量 多重免疫荧光(IF)揭示治疗如何调节转移性PDAC的成纤维细胞亚群。 第二，我们将确定靶向IL-6和PD-1如何影响T细胞和髓系细胞在 转移性PDAC肿瘤和体循环。我们将利用单细胞质量细胞术的方法 配对活检和血液研究转移瘤和全身纵向的免疫表型重编程 治疗过程中的变化及其与临床疗效的关系。这项研究将影响我们对 免疫治疗可以得到改进，并提供与基质和免疫标记物相关的丰富数据集 转移性PDAC为后续治疗机会提供便利。

PROJECT SUMMARY Pancreatic ductal adenocarcinoma (PDAC) harbors significant barriers restraining immunity. One notable factor is the fibrotic stroma, driven by cancer associated fibroblast (CAF) subsets. Another is the myeloid-skewed immune composition of TIL in PDAC tumors, which lack robust effector T cell infiltration. We postulate that interleukin-6 (IL-6) is a critical factor that promotes inflammatory CAF, enables suppressive myeloid cell residence, along with T cell dysfunction in PDAC. Using innovative translational approaches and patient specimens, we will address relationships between IL-6, CAF and the balance of myeloid and T cells in metastatic human PDAC. Studies in pre-clinical models support a role for these factors in both primary and metastatic PDAC tumors, and our work will invigorate further discovery by studying tumor and blood samples from patients where IL-6, a key cytokine mediator, is blocked along with the PD-1 immune checkpoint. This data will enhance our understanding of how CAF interact with cytokines and immune cells in metastatic foci. This proposal addresses the scientific premise that IL-6 acting directly on CAF and immune cells are key mechanisms for maintaining an immunologically “cold” tumor microenvironment (TME) in metastatic PDAC and contributes to immunotherapy resistance. We will test our overall hypothesis that IL-6 restrains immunity against PDAC, through its effects on CAF and immune cells, and that targeting it reprograms the TME to enhance efficacy of immunotherapy. Prior publications from our group have demonstrated a role for IL-6 in PDAC and shown in mouse models how targeting it can improve efficacy of immune checkpoint blockade. These extensive efforts have culminated in this proposal, which will translate into patients a first-in-human trial of IL-6 and PD-1 blockade in PDAC. This trial provides a needed study of how IL-6 and CAF are related to balance of immune cells in metastatic tumors. This proposal represents an important opportunity to uncover connections between CAF, immune cells and IL-6 in metastatic disease in patients. We will conduct two specific aims. First, we will determine how dual blockade of IL-6 and PD-1 orchestrates the balance of CAF populations in tumors from metastatic PDAC patients. In this aim, we will generate foundational data using human samples from paired pre- and on-treatment biopsies of PDAC metastases from the clinical trial. Composition of CAF will be measured via multiplex immunofluorescence (IF) to uncover how therapy modulates fibroblast subsets in metastatic PDAC. Second, we will determine how targeting IL-6 and PD-1 influences the balance of T and myeloid cells in metastatic PDAC tumors and systemic circulation. We will utilize single cell mass cytometry approaches on paired biopsies and blood to study immune phenotype reprogramming in metastases and systemic longitudinal changes during treatment and relationship to clinical response. This study will impact our understanding of how immunotherapy can be improved and provide a rich dataset related to both stroma and immune markers in metastatic PDAC to facilitate subsequent treatment opportunities.