Mechanisms of immune control of intratumor heterogeneity and clonal competition

项目摘要/摘要 肿瘤内异质性(ITH)和克隆性进化对设计有效的 以及持久的癌症疗法。这与前列腺癌高度相关，它是一种高度异质性疾病的典型例子。 具有不同突变和表型特征的波动细胞亚群(克隆)可以共存的地方 并在疾病过程中独立进化、多样化和竞争。ITH研究的大部分 集中在遗传决定因素上，而非遗传变异性，如由于空间克隆分布和 肿瘤亚群之间的相互作用以及与免疫TME之间的相互作用仍然知之甚少。这些 机制是多方面的，与环境有关，很难在体内进行实验研究。然而， 这些复杂的相互作用可能会带来强大的抗肿瘤干预。例如，消除机制 可能被利用来降低总体肿瘤适合性，新的靶向治疗可能是 被开发来抵消使克隆优势成为可能的因素。我们最近产生了新的简化论者 ITH模型至少部分地反映了人类PCA的克隆适应度多样性。通过融合多种颜色 在小鼠模型中的谱系追踪，纵向器官研究和单细胞转录组，我们表明 不太严重的模型适应了多个生长肿瘤亚群的共存。相比之下， 侵袭性肿瘤表现出急剧和快速的克隆减少，出现了更大的优势种群 在体内和体外，增长较慢的种群被快速增长的种群和大规模的TME所击败 改建。与此同时，一些少数群体持续存在，并可能成为抗药性的储存库。 克隆人。此外，少数群体具有明显的免疫编辑分子特征，标记为增加 Cxcl9/Cxcl11和MHC II类成员的表达。我们假设直接竞争机制 在特定的TME生态位内的显性克隆和次要克隆之间的关系以及免疫的适应效果 克隆扩增系统决定了PCa中的ITH。这项提议的目标是识别分子 相互克隆相互作用的机制和细胞环境，以及与TME的相互作用 空间转录技术在小鼠前列腺癌模型中肿瘤竞争景观的功能定位 分析和2)阐明Cxcl9/11在降低小无性系适应潜力中的作用 竞争趋化性和T细胞渗入有机物分析和体内免疫调节干预。 这些研究的结果不仅将极大地扩展我们对种群水平相互作用的理解 在肿瘤中，还发现了新的有针对性的免疫编辑机制，这些机制在克隆水平上操作 克隆多样化和选择对预防晚期疾病和药物进展的影响 抵抗。

PROJECT SUMMARY/ABSTRACT Intratumor heterogeneity (ITH) and clonal evolution pose tremendous challenges in designing effective and durable cancer therapies. This is highly relevant for PCa, a prime example of a highly heterogenous disease where fluctuating cellular subpopulations (“clones”) with distinct mutational and phenotypic profiles can coexist and evolve independently, diversify and compete during the course of the disease. The majority of ITH studies centers on genetic determinants, while non-genetic variability such as due to spatial clonal distributions and interactions of tumor subpopulations with each other and with the immune TME remain poorly understood. These mechanisms are multifaceted, context-dependent and difficult to investigate experimentally in vivo. However, these complex interactions might hold powerful anti-tumor interventions. For instance, mechanisms of elimination of “loser” cells/clones could be exploited to lower overall tumor fitness and new targeted therapies could be developed to counteract the factors that enable clonal dominance. We recently generated new reductionist models of ITH that reflect, at least in part, the clonal fitness diversity of human PCa. By incorporating multicolor lineage tracing in mouse models, longitudinal organoid studies and single cell transcriptomics, we showed that less severe models accommodate the coexistence of multiple growing tumor subpopulations. In contrast, aggressive tumors exhibit a drastic and rapid clonal reduction, emergence of larger dominant populations as slower-growing populations are out-competed by fast-growing ones in vivo and in vitro, and massive TME remodeling. In the same time, some minor populations persist and might serve as a reservoir for drug-resistant clones. Moreover, the minor populations have distinct immunoediting molecular signatures marked by increased expression of Cxcl9/Cxcl11 and MHC class II members. We hypothesize that direct competition mechanisms between dominant and minor clones within specialized TME niches coupled with fitness effects of the immune system on clonal expansions determine the ITH in PCa. The goal of this proposal is to identify molecular mechanisms and cellular contexts underlying clonal interactions with each other and with TME by pursuing 1) Functional mapping of tumor competitive landscapes in mouse models of PCa by spatial transcriptomic analyses and 2) Elucidate the role of Cxcl9/11 in reducing the fitness potential of minor clones by novel competition-chemotaxis and T-cell infiltration organoid assays and in vivo immunomodulatory interventions. Results from these studies will not only greatly expand our understanding of population-level interactions in tumors, but also uncover new targetable immunoediting mechanisms that operate at clonal level in driving clonal diversification and selection with impact on preventing progression to advanced disease and drug resistance.