(PQB2) Ontogeny of the tumor-immune interplay in a developmental malignancy

描述(由申请人提供)：这个R21项目解决了NCI的挑衅性问题#PQB2。这项建议的意义将是建立管理恶性肿瘤的初始免疫识别以及免疫抑制肿瘤微环境如何出现的原则。癌症生物学中的一个基本问题是，我们不了解免疫-肿瘤相互作用的规则，也不了解免疫反应如何识别新出现的恶性肿瘤的早期阶段并与其相互作用。免疫系统是否会在一生中抑制癌症，但偶尔会失败，目前仍存在争议。一个相关的争论问题涉及癌症如何与自身区分的机制：解决这个问题的尝试放弃了数十年来对肿瘤抗原及其潜在临床用途的研究。巨噬细胞是最早形成一种新生的恶性肿瘤的免疫细胞。巨噬细胞滋生肿瘤的原因尚不清楚，但可能是其组织修复和恢复功能的结果：巨噬细胞很可能是在研究一个健康的“器官”。巨噬细胞来自不同的来源：卵黄囊/胎肝来源的组织、巨噬细胞和来源于血液单核细胞池的巨噬细胞。在肿瘤生长的早期阶段，巨噬细胞的来源尚不清楚。我们的模型是癌变的第一步，包括来自组织和血液来源的巨噬细胞之间的相互作用，共同建立组织修复和免疫抑制微环境。因此，实验解剖髓系细胞对肿瘤的初始识别是理解恶性肿瘤形成的关键之一。为了剖析最初的免疫-肿瘤相互作用，我们将使用癌症的一个发育模型：神经母细胞瘤(NB)，这是儿童最常见的实体肿瘤。通过综合遗传、成像和免疫学方法，我们将追踪早期恶性肿瘤的免疫识别的个体发育，而不需要原位移植肿瘤细胞来启动癌症。为了解决PQB2，我们将确定随着时间的推移髓系重新聚集到不断增长的肿瘤中的原则(目标1)。利用NB的遗传模型，我们将量化从最早可检测到的肿瘤大小到更大的恶性肿瘤的髓系细胞的来源和性质。在目标2中，我们将量化PRO- 和新生恶性肿瘤中的抗肿瘤T细胞。使用NB，我们将通过肿瘤相关抗原的四聚体染色来量化CD8+T细胞反应，并将这些数据与局部Treg的数量和活性相关联。通过结合四聚体染色、体内可视化技术和组织与单核细胞来源的巨噬细胞的操作，我们将确定T细胞如何与不断增长的恶性肿瘤相互作用，以及T细胞反应和局部髓系群体之间的关系。

DESCRIPTION (provided by applicant): This R21 project addresses the NCI's Provocative Questions #PQB2. The significance of this proposal will be to establish principles governing the initial immune recognition of malignancy, and how the immunosuppressive tumor microenvironment emerges. A fundamental problem in cancer biology is that we do not understand the rules governing the immune-tumor interplay, nor do we understand how the immune response recognizes and interacts with the early phases of an emerging malignancy. Whether the immune system constrains cancer throughout life but occasionally fails remains contentious. A related issue of contention concerns the mechanisms of how cancer is discriminated from self: attempts to address this question have spurned decades of research into tumor antigens and their potential clinical uses. Macrophages are the earliest immune cells to populate a nascent malignancy. Why macrophages populate tumors remains unexplained, but is a probably a consequence of their tissue repair and recovery functions: macrophages are likely surveying an 'organ' for health. Macrophages come from different sources: the yolk sac/fetal liver-derived tissue macrophages and macrophages originating from the blood monocyte pool. In the earliest phases of tumor growth, the source of macrophages is unclear. Our model is the first steps of malignancy involve an interplay between macrophages from both tissue and blood sources conspiring to establish the tissue repair and immunosuppressive microenvironment. Therefore, experimental dissection of the initial recognition of tumors by myeloid cells is one key to understanding how malignancy is established. To dissect the initial immune-tumor interplay we will use a developmental model of cancer: Neuroblastoma (NB), the most common solid tumor of childhood. Through integrated genetic, imaging and immunological approaches we will trace the ontogeny of immune recognition of early malignancy without the need to orthotopically transplant tumor cells to initiate cancer. To address PQB2 we will determine the principles governing myeloid recruitment to a growing tumor across time (Aim 1). Using genetic models of NB, a developmental tumor growing in a defined location and within a predictable time window, we will quantify the source and properties of myeloid cells infiltrating tumors from the earliest detectable size to larger malignancies. In Aim 2 we will quantify the pro- and anti-tumor T cells in nascent malignancies. Using NB, we will quantify CD8+ T cell responses using tetramer staining for a tumor linked antigen and correlate these data with the number and activity of local Treg. By combining tetramer staining, in vivo visualization techniques and manipulation of tissue versus monocyte-derived macrophages we will determine how T cells interact with growing malignancies, and the relationship between the T cell response and local myeloid populations.