Breaking down tumor immune privilege through targeted hypoxia reduction

项目概要/摘要 肿瘤缺氧预示着所有癌症的不良结局，并且是对这两种癌症产生耐药性的公认来源。 化疗和放疗。我们已经证明，T细胞不能在癌症的缺氧区生长，这是癌症的基础。 免疫“冷”适应症（如胰腺癌和前列腺癌）的检查点阻断失败。虽然我们的 先前的工作依赖于我们的偶然发现，即缺氧激活的前药TH-302可以有效地 减少肿瘤缺氧，目前还没有研究确定最有效的手段，以减少缺氧， 癌从机制上讲，肿瘤缺氧是由氧气供应减少与肿瘤生长抑制相结合引起的。 肿瘤耗氧量增加。虽然这些影响中的每一个都有助于促进缺氧和核化， 免疫抑制状态，没有什么是已知的相对重要性，在建立缺氧状态 本身，也没有它们对缺氧区域内的肿瘤浸润T细胞的差异影响。此外，我们缺乏一个 了解低氧减少的持久性因素，以及任何限制肿瘤生长的干预措施。 恢复缺氧状态的能力。在更深层次上，缺氧引发的精确分子信号， 重新编程基质中的骨髓细胞和肌成纤维细胞，以代谢适应缺氧状态，并获得 免疫抑制功能也仍不清楚。因此，我们假设肿瘤缺氧和 可以减少骨髓基质和肌成纤维细胞基质的相关免疫抑制编程 通过局部组织重塑和通过限制肿瘤氧代谢。我们的首要目标是 为了确定缺氧活化的前药、氧化性前药和氧化性前药对缺氧和免疫浸润调节的动力学， 磷酸化（OxPhos）抑制剂和抗血管生成剂。对于每个类，我们将建立动力学 他们减少缺氧的方式，治疗后这种减少的持久性，以及重新治疗是否可以 消除再发性缺氧。这是第一次系统的研究，不仅将揭示最佳的方法， 在免疫增强的背景下减少肿瘤缺氧，但也将提供对相对 氧供应中断与肿瘤氧消耗升高对建立缺氧的贡献。 其次，我们将研究OxPhos抑制剂对肿瘤和T细胞代谢以及缺氧的影响。 健身我们将评估三种OxPhos代谢抑制剂如何靶向复合物I的不同亚基， 影响肿瘤与T细胞代谢、功能和低氧适应。这些研究将提供关键的 了解肿瘤氧消耗是否可以以损害肿瘤缺氧的方式被抑制 在不损害抗肿瘤免疫功能的前提下，第三个目标 该方案利用了肿瘤髓系中缺乏缺氧诱导因子1-α（HIF 1 α）或HIF 2 α的小鼠， 基质或肌成纤维细胞，以映射负责功能和代谢编程的下游信号 这些细胞对缺氧的反应这些研究将提供重要的见解，使临床缺氧减少 来提高我们对“冷”癌症的免疫治疗能力。

PROJECT SUMMARY/ABSTRACT Tumor hypoxia predicts poor outcomes across all cancers and is a well-established source of resistance to both chemo- and radiotherapy. We have shown that T cells fail to thrive in hypoxic zones of cancer underlying the failure of checkpoint blockade for immune “cold” indications such as pancreatic and prostate cancer. While our prior work relied on our serendipitous discovery that the hypoxia-activated prodrug, TH-302, could efficiently reduce tumor hypoxia, there have been no studies to identify the most effective means to reduce hypoxia in cancer. Mechanistically, tumor hypoxia results from the combination of diminished oxygen supply coupled with enhanced tumor oxygen consumption. While each of these influences helps to foster hypoxia and nucleate an immune suppressive state, nothing is known of their relative importance in establishment of the hypoxic state itself, nor of their differential impact on tumor-infiltrating T cells within hypoxic regions. Further, we lack an understanding of the factors governing durability of hypoxia-reduction, and of any interventions to limit tumors’ capacity to restore the hypoxic state. At a deeper level, the precise molecular signals triggered by hypoxia, which reprogram myeloid and myofibroblast cells in the stroma to adapt metabolically to the hypoxic state and acquire immune suppressive function also remain unclear. We therefore hypothesize that tumor hypoxia and associated immune suppressive programming of the myeloid and myofibroblast stroma can be reduced through both local tissue remodeling and through limitation of tumor oxygen metabolism. Our first aim is to determine the kinetics of hypoxia and immune infiltrate modulation by hypoxia-activated prodrugs, oxidative phosphorylation (OxPhos) inhibitors, and anti-angiogenic agents. For each class, we will establish the kinetics by which they reduce hypoxia, how durable that reduction is post-therapy, and whether re-treatment can eliminate re-emergent hypoxia. This first of its kind systematic study will not only reveal optimal approaches for reducing tumor hypoxia in an immune-potentiating context but will also provide insights into the relative contribution of disrupted oxygen supply versus elevated tumor oxygen consumption toward establishing hypoxia. Second, we will investigate the impact of OxPhos inhibitors on both tumor and T cell metabolism and hypoxic fitness. We will assess how three inhibitors of OxPhos metabolism, which target distinct subunits of Complex I, impact tumor versus T cell metabolism, function, and hypoxic adaptation. These studies will provide critical insight into whether tumor oxygen consumption can be inhibited in a manner which compromises tumor hypoxic fitness and immune privilege without damaging the functional capacity of anti-tumor immunity. The third aim of this proposal utilizes mice lacking hypoxia-inducible factor 1-alpha (HIF1α) or HIF2α in either their tumor myeloid stroma or myofibroblasts to map the downstream signals responsible for functional and metabolic programming of these cells in response to hypoxia. These studies will provide critical insights allowing clinical hypoxia reduction to improve and with it our capacity for immunotherapy of “cold” cancers.