Ontogeny and Function of Tumor-Resident Innate Lymphocytes and Innate-Like T Cells

项目摘要 癌症免疫监控归因于免疫系统在抑制肿瘤发展中的作用。癌 免疫治疗方法，如检查点封锁，恢复耗尽的T细胞的这一功能 彻底改变了癌症患者的护理。尽管如此，许多患者对这种癌症形式没有反应。 治疗，呼吁对更广泛的肿瘤引起的免疫反应进行调查。我们有 最近发现，肿瘤生长诱导组织驻留的细胞毒性先天淋巴细胞的扩张，并 与生俱来的T细胞共享与NK细胞和耗尽的T细胞不同的基因表达程序。 这些细胞的特征是高表达转录因子Hobit和细胞溶解颗粒酶 本文将其命名为先天淋巴样细胞(ILCk)和类T细胞(ILTCk)。值得注意的是，基因枯竭 ILCk和ILTCk的结合可加速肿瘤生长。此外，肿瘤细胞表达高水平的IL-15 并失去E-钙粘蛋白的极性，IL-15或E-钙粘蛋白缺乏会耗尽ILCk和ILTCk，导致 加速了肿瘤的生长。基于这些发现，我们假设ILCk和ILTCk是新的 细胞毒性淋巴细胞，它们通过感应肿瘤细胞来源的IL-15而发挥细胞转化的哨兵作用 和E-钙粘附素。为了验证这一假说，我们将首先定义ILCk和ILTCk的发育途径。通过 进行细胞转移和细胞命运图实验，以及使用谱系指定缺陷的小鼠 对于转录因子，我们将评估ILCk是否沿着固有淋巴样细胞谱系分化。在……里面 此外，我们还将培育T细胞受体(TCR)逆转录小鼠，并进行TCR“交换”实验 确定不同的胸腺选择是否促进ILTCk分化。异型共生和诱导 还将进行针对造血干细胞的细胞命运图谱实验，以确定 ILCk和ILTCk在整个肿瘤进展过程中不断产生。其次，我们将定义 通过初步评估Hobit表达是否标志着一个阶段的ILCk和ILTCk的功能和调节 功能规范，以及Hobit是否控制ILCk和ILTCk所必需的基因表达程序- 通过媒介进行癌症监测。此外，我们还将利用Il15和Il2rb的条件性零等位基因和一个- 编码转录因子Stat5b活性形式的功能等位基因决定肿瘤IL-15 作为ILCk和ILTCk的警报器，以及IL-15信号是否构成 ILCk和ILTCk响应。最后，我们将研究肿瘤细胞与ILCk和ILTCk之间的相互作用 通过活体成像，并评估E-钙粘附素是否被转化生长因子-β诱导的整合素CD103感知，以及 患者CDH1热点错义突变是否促进ILCk和ILTCk介导的肿瘤逃逸 癌症监测。这个项目的成功完成不仅将产生对 肿瘤驻留的ILCk和ILTCk的谱系承诺和调控，但也指导了这一新的靶向 治疗多种恶性肿瘤的癌症免疫监测途径。

Project Summary Cancer immunosurveillance ascribes a role of the immune system in repressing tumor development. Cancer immunotherapy approaches such as checkpoint blockade that revives this function of exhausted T cells have revolutionized cancer patient care. Nonetheless, many patients do not respond to this modality of cancer treatment, calling for investigation of a broader spectrum of tumor-elicited immune responses. We have recently shown that tumor growth induces expansion of tissue-resident cytotoxic innate lymphocytes and innate-like T cells that share a gene expression program distinct from that of NK cells and exhausted T cells. Characterized by high expression of the transcription factor Hobit and cytolytic granzymes, these cells are herein named killer innate lymphoid cells (ILCk) and killer innate-like T cells (ILTCk). Notably, genetic depletion of ILCk and ILTCk results in accelerated tumor growth. Furthermore, tumor cells express high levels of IL-15 and lose E-cadherin polarity, and IL-15 or E-cadherin deficiency depletes ILCk and ILTCk resulting in accelerated tumor growth. Based on these findings, we hypothesize that ILCk and ILTCk are novel lineages of cytotoxic lymphocytes, and they function as sentinels of cell transformation by sensing tumor cell-derived IL-15 and E-cadherin. To test this hypothesis, we will first define the developmental pathways of ILCk and ILTCk. By performing cell transfer and cell fate-mapping experiments as well as using mice deficient in lineage-specifying transcription factors, we will assess whether ILCk are differentiated along the innate lymphoid cell lineage. In addition, we will generate T cell receptor (TCR) retrogenic mice and perform TCR “swapping” experiments to determine whether distinct thymic selection promotes ILTCk differentiation. Parabiosis and inducible hematopoietic stem cell-targeted cell fate-mapping experiments will also be performed to determine whether ILCk and ILTCk are continuously generated throughout tumor progression. Secondly, we will define the function and regulation of ILCk and ILTCk by initially assessing whether Hobit expression marks a stage of functional specification, and whether Hobit controls a gene expression program essential for ILCk and ILTCk- mediated cancer surveillance. In addition, we will utilize conditional null alleles of Il15 and Il2rb and a gain-of- function allele encoding an active form of the transcription factor Stat5b to determine whether tumor IL-15 functions as an alarmin for ILCk and ILTCk, and whether IL-15 signaling constitutes a rate-limiting step of the ILCk and ILTCk response. Finally, we will investigate the interactions between tumor cells and ILCk and ILTCk by intravital imaging, and assess whether E-cadherin is sensed by the TGF-b-induced integrin CD103, and whether patient CDH1 hot-spot missense mutations promote tumor evasion from ILCk and ILTCk-mediated cancer surveillance. Successful completion of this project will not only generate mechanistic insights into the lineage commitment and regulation of tumor-resident ILCk and ILTCk, but also guide the targeting of this novel cancer immunosurveillance pathway for therapy of a wide range of malignancies.