Autochthonous and Ex-vivo Derived Mouse Models of Malignant Glioma

项目总结/摘要 尽管投入了大量的资源来开发更好的治疗方法，多形性胶质母细胞瘤（GBM） 患者面临着治疗选择的匮乏，并且普遍具有较差的结果。经过治疗， 生存期为15个月。免疫治疗可能拥有最大的潜力来对抗这种可怕的疾病。 然而，关于免疫系统和大脑之间的关系，仍然存在许多问题， 尤其是免疫系统和脑癌。免疫反应的哪些组成部分是 对胶质母细胞瘤的免疫反应是不可或缺的为什么免疫系统最终无法控制 GBM？此外，我们如何利用免疫反应来更好地治疗胶质母细胞瘤？该项目的重点是 为了探究胶质母细胞瘤的这些方面，有效地做到这一点，首先要有更好的小鼠模型， 这个项目的核心。 免疫编辑假说假设癌细胞呈现源自其自身的肽 突变的蛋白质，可以被免疫系统识别为外来物。这些突变的功能是 靶点，可以标记肿瘤被细胞毒性T细胞破坏。在此过程中， 肿瘤进化成免疫原性较低，并与免疫系统保持平衡。最终 肿瘤产生较低免疫原性的靶标，并且有效地变得对免疫系统不可见。在这个 在这一点上，肿瘤逃脱了免疫系统的控制，并出现在临床上。这个过程是如何发生的 对中枢神经系统的影响还不太清楚人类GBM带来了额外的挑战，因为它们 携带低突变负荷，因此具有很少的突变靶向。目前的GBM小鼠模型要么具有 高突变负荷或低突变负荷，但由于各种原因不适合研究肿瘤免疫 系统交互。该项目的模型将使用慢病毒作为传递两种致癌蛋白的手段 和Cre重组酶以精确的方式切除loxP侧翼的肿瘤抑制子， 小鼠，具有纯遗传背景。这种原位的临床前模型将更忠实地 概括了这种疾病在人类身上发生的情况。该系统还将用于开发一种超突变的 复发性GBM模型，以建立突变负荷和检查点阻断之间的关系 CNS肿瘤的敏感性。由于以下原因，这些模型在模拟人类疾病方面将是上级 它们的低突变负担，因为遗传靶向是精确的，因为免疫系统将如何“看到” 肿瘤与人类疾病相似，并且由于肿瘤形成的原位性质。 这些GBM的基因工程小鼠模型将回答有关如何 免疫系统与GBM相互作用，将建立突变负荷与检查点之间的关系， 阻断CNS肿瘤的敏感性，并有望导致更有效的治疗方法的发展。

PROJECT SUMMARY/ABSTRACT Despite immense resources devoted to developing better treatments, glioblastoma multiforme (GBM) patients face a paucity of treatment options and universally have poor outcomes. With treatment, the median survival is fifteen months. Immunotherapy treatment likely holds the greatest potential to combat this terrible disease, and yet many questions remain regarding the relationship between the immune system and the brain, and in particular, the immune system and cancer of the brain. Which components of immune response are indispensable for the immune response to glioblastoma? Why does the immune system ultimately fail to control GBM? Further, how can we leverage the immune response to better treat glioblastoma? This project focuses on interrogating these aspects of glioblastoma, and to effectively do so begins with better mouse models, which is the central thrust of this project. The immune editing hypothesis postulates that cancer cells present peptides derived from their own mutated proteins, which can be recognized as foreign by the immune system. These mutations function as targets, which can mark the tumor for destruction by cytotoxic T cells. During the course of this process, the tumor evolves to become less immunogenic and persists in equilibrium with the immune system. Eventually, the tumor gives rise to less immunogenic targets and effectively becomes invisible to the immune system. At this point, the tumor escapes beyond the immune system’s control and presents clinically. How this process occurs in the central nervous system is less well understood. Human GBMs pose the additional challenge in that they carry low mutational burden, and hence have few mutations to target. Current mouse models of GBM either have high mutational burden, or low mutational burden but are for various reasons unsuitable to study tumor-immune system interactions. The model for this project will use lentivirus as a means to deliver both oncogenic proteins and Cre-recombinase to excise loxP flanked tumor-suppressors in a precise way, in immunologically mature mice, of a pure genetic background. This autochthonous, orthotopic pre-clinical model will more faithfully recapitulate the disease as it occurs in humans. This system will also be employed to develop a hypermutated model of recurrent GBM to establish the relationship between mutational burden and checkpoint blockade sensitivity in CNS tumors. These models will be superior for simulating the disease seen in humans because of their low mutational burden, because the genetic targeting is precise, because how the immune system will “see” the tumor is similar to the human disease, and because of the autochthonous nature of tumor formation. These genetically engineered mouse models of GBM will answer fundamental questions regarding how the immune system interacts with GBM, will establish the relationship between mutational burden and checkpoint blockade sensitivity of CNS tumors, and will hopefully lead to development of more effective treatments.