Investigating Macrophage Molecular and Functional Diversity in Tumor Immunity

项目总结 巨噬细胞是肿瘤病变中最大的免疫细胞成分之一，其数量 甚至可以超过癌细胞。Mf在形成肿瘤微环境的组成中起关键作用。 肿瘤天然免疫和获得性免疫的调节，以及对癌症免疫治疗的反应。 由于它们的关键作用，MF是癌症治疗的重要靶点。然而，调节肿瘤- 事实证明，与之相关的MF非常困难。这在很大程度上是因为我们仍然没有一个完整的 对肿瘤间隔室的认识。为了开发调节肿瘤微循环的方法并促进 肿瘤免疫，这是至关重要的，我们得到了更深入的了解分子和功能多样性的MF在 他们的组织背景。 利用质量细胞术(CyTOF)和单细胞rna-seq(scRNA-seq)，我们启动了对 早期非小细胞肺癌(NSCLC)的免疫成分我们发现了 在人类肿瘤中丰富的多个不同的MF种群。值得注意的是，相关的MF集群也在#年被确定 小鼠肺癌病变。利用命运图谱和scrna-seq，我们发现了这些离散的mf种群。 发育起源不同，在TME有明显的分布。当MF的不同子集是 肿瘤耗尽，肿瘤生长受到损害，但TME的变化不同，提示有不同的机制 活动。根据我们的发现，我们假设MF的独特子集具有不同的分子状态 并调节对肿瘤生长、组织、免疫和对PD1阻断的反应的不同贡献。 为了解决我们的假设，我们将：(1)全面绘制人类肺部肿瘤的MF区图，在 在非小细胞肺癌中，基线和PD1阻断治疗期间的单细胞水平和空间分辨率 参加新辅助免疫疗法临床试验的患者，(2)评估DISTINCT的功能贡献 MF亚群在TME中对肿瘤组织重塑和免疫细胞动力学的影响，以及(3)决定其贡献 不同的MF亚群对肺肿瘤免疫的影响。我们还将研究(4)特定的功能和活性 细胞表面受体TREM2，我们发现它仅在单核细胞来源的MF上表达，在两种情况下 人和小鼠肺肿瘤，其基因敲除会损害肺肿瘤的生长，类似于MF耗竭； 提示在MF控制肿瘤生长中有一个重要的和潜在的靶向分子。 这些研究的结果将(I)揭示Mf隔室的分子和功能多样性 确定不同的分枝杆菌亚群和分枝杆菌特异性基因如何影响肿瘤生长， TME状态和肿瘤免疫，以及(Iii)提供对MF亚群如何影响和被影响的洞察 在人非小细胞肺癌中，PD1被阻断。这些研究有可能帮助我们理解一些因素 有助于肿瘤的反应和对免疫编辑的抵抗，并有助于进一步的发展和 肿瘤免疫治疗策略的临床应用。

PROJECT SUMMARY Macrophages (MF) are one of the largest immune cell components of tumor lesions, where their numbers can even exceed cancer cells. MF play a key role in shaping the composition of the tumor microenvironment (TME), the modulation of tumor innate and adaptive immunity, and the response to cancer immunotherapy. Because of their critical roles, MF are an important target for cancer treatment. However, modulating tumor- associated MF has proved extremely difficult. This is in large part because we still do not have a complete understanding of the tumor MF compartment. In order to develop ways to modulate tumor MF and promote cancer immunity, it is vital we gain a deeper understanding of the molecular and functional diversity of MF in their tissue context. Using mass cytometry (CyTOF) and single cell RNA-seq (scRNA-seq), we initiated deep characterization of the immune composition of early human non-small cell lung carcinomas (NSCLC). We uncovered evidence of multiple distinct MF populations enriched in human tumors. Notably, related MF clusters were also identified in mice lung cancer lesions. Using fate mapping and scRNA-seq, we discovered these discrete MF populations differ in developmental origin and have a distinct distribution in the TME. When the different subsets of MF were depleted, tumor growth was impaired, but the alterations in TME differed, suggesting distinct mechanisms of activity. Based on our findings, we hypothesize that the unique subsets of MF have differential molecular states and mediate differential contributions to tumor growth, organization, immunity, and response to PD1 blockade. To address our hypothesis, we will: (1) comprehensively map the MF compartment of human lung tumors, at the single cell level and with spatial resolution, at baseline and during treatment with PD1 blockade, in NSCLC patients enrolled in a neoadjuvant immunotherapy clinical trial, (2) assess the functional contribution of distinct MF subsets to tumor tissue remodeling and immune cell dynamics in the TME, and (3) determine the contribution of distinct MF subsets to lung tumor immunity. We will also (4) investigate the function and activity of a specific cell surface receptor, Trem2, which we found to be exclusively expressed on monocyte-derived MF in both human and mouse lung tumors, and whose knockout impaired lung tumor growth similar to MF depletion; suggesting an important and potentially targetable molecule in MF control of tumor growth. The outcome of these studies will (i) uncover the molecular and functional diversity of the MF compartment of human lung tumors, (ii) determine how distinct MF subsets, and MF-specific genes, influence tumor growth, the TME state, and tumor immunity, and (iii) provide insight into to how MF subsets influence, and are influenced by, PD1 blockade in human NSCLC. These studies have the potential to help us understand some of the factors that contribute to tumor response and resistance to immune editing, and aid in the further development and clinical use of cancer immunotherapy strategies.