Immune Regulation of Disseminated Cancer Cell Dormancy

摘要：大多数癌症患者不是死于原发肿瘤，而是死于转移性疾病。在此之前 致命性转移的形成，播散性癌细胞(DCC)可能会休眠长达数十年，如 临床表现为微小残留病(MRD)，尚无有效治疗方法。免疫疗法 已经取得了重大进展。然而，大多数研究都集中在原发肿瘤上。我们知道的要少得多 对于转移性疾病，特别是对MRD。这项提案的首要目标是揭示 参与休眠DCC与免疫系统相互作用的机制，从而揭示 在发展成一种完全致命的疾病之前，MRD的治疗机会。我们将决定 潜伏期DCC及其相关免疫细胞与外生性转移相关的特异性表型 使用单细胞RNA测序、质量细胞术(或称CyTOF)和纳米串技术。一个重要的 在整个研究过程中将使用的临床前模型是MMTV-ErbB2小鼠，它们会自发发展 次级器官中的休眠DCC。与广泛使用的涉及已建立的移植的模型相比 无论是肿瘤还是疫苗接种，这种模型将更好地模拟患者的真实情况，因为免疫系统协同 从癌细胞一开始就和它们一起进化。在目标1中，我们将确定T细胞是否抑制了 DCCs通过休眠的诱导及其相关机制。我们将测试T细胞耗尽是否会导致 MMTV-ErbB2模型中休眠DCC的重新激活，以及作为补充的原位模型。我们 还将测试免疫细胞因子是否在3D有机培养物和活体中诱导DCC休眠，并确定 这些细胞因子的细胞来源。在目标2中，我们将确定DCC是否使用休眠程序来诱导 通过调节免疫检查点进行免疫抑制/逃避。具体地说，我们将测试休眠- 诱导细胞因子和转录因子调节免疫调节因子的表达。免疫逃避 确定DCC是否一般使用休眠程序来避免免疫反应和 因此要坚持下去。我们还将测试免疫检查点抑制剂是否能使免疫反应对抗休眠状态 DCC。总之，这些方法将使我们能够了解免疫系统是否诱导DCC休眠，如果 休眠程序使免疫反应的抑制得以逃避，如果干预这些 进程将消除休眠的DCC。因此，这项研究应该揭示治疗MRD的机会。 从而最大限度地减少导致大多数癌症患者死亡的疾病复发。

SUMMARY: Most cancer patients do not die from primary tumors but from the metastatic disease. Before formation of lethal metastases, disseminated cancer cells (DCCs) may stay dormant for up to decades, shown in clinics as the minimal residual disease (MRD), for which effective therapies are unavailable. Immunotherapies have made significant progress. However, most of the research focuses on primary tumors. Much less is known for the metastatic disease, in particular for MRD. The overarching goal of this proposal is to uncover mechanisms involved in the interaction between dormant DCCs and the immune system and therefore reveal therapeutic opportunities for MRD before the development into a full-blown lethal disease. We will determine the specific phenotypes of dormant DCCs and the associated immune cells relative to outgrowing metastases using single-cell RNA-sequencing, mass cytometry (or CyTOF), and Nanostring technologies. An important preclinical model that will be used throughout the study is the MMTV-ErbB2 mice, which develop spontaneous dormant DCCs in secondary organs. Compared to widely used models involving transplantation of established tumors or vaccination, this model will better mimic real-life situations in patients, as the immune system co- evolve with the cancer cells since their inception. In Aim 1, we will determine if T cells inhibit the expansion of DCCs via induction of dormancy and the mechanisms involved. We will test if T cell depletion allows the reactivation of dormant DCCs in the MMTV-ErbB2 model but also an orthotopic model as a complement. We will also test if immune cytokines induce DCC dormancy in 3D organoid cultures and in vivo and determine the cellular source of these cytokines. In Aim 2, we will determine if DCCs use the dormancy program to induce immune-suppression/-evasion via regulation of immune checkpoints. Specifically, we will test if dormancy- inducing cytokines and transcription factors regulate expression of immunoregulatory factors. immune-evasion genes to determine if the dormancy program in general is used by DCCs to avoid immune response and therefore persist. We will also test if immune checkpoint inhibitors enable immune reactions against dormant DCCs. Together, these approaches will allow us to understand if the immune system induces DCC dormancy, if the dormancy program enables evasion of suppression of the immune response, and if intervention of these processes will eliminate dormant DCCs. Thus, this study should reveal therapeutic opportunities to treat MRD and thereby minimize the disease recurrence that kills the majority of cancer patients.