The role of Notch signaling in human natural killer cell functional maturation

项目总结/摘要 我们在这个项目中的长期目标是阐明人类自然杀伤细胞发育的机制， 目的是将NK细胞生物学过程应用于癌症治疗。自然杀伤（NK）细胞识别 恶性细胞在其表面上缺乏自身MHC分子，从而靶向它们进行穿孔素介导的免疫调节。 细胞毒NK细胞在对恶性肿瘤的先天性免疫应答中起重要作用， 癌症如急性髓性白血病（AML）已显示具有受损的NK细胞发育， 功能因此，了解NK细胞成熟的未知机制， 正常和疾病环境将改善癌症治疗的转化研究工作。我们正在进行的工作 研究次级淋巴组织（包括扁桃体）中NK细胞的发育途径 和淋巴结）。在我们目前的研究中，我们观察到Notch信号通路的激活导致 在从无功能表型到功能成熟NK细胞的发育过程中的关键转变。此外，委员会认为， 我们在新鲜的成熟NK细胞中检测到Notch转录活性结构域的组成型表达， 分离自扁桃体，因此支持Notch在调节功能表型中的生理重要性 成熟的NK细胞。我们假设，Notch信号在微环境中调节了细胞的生长。 从未成熟到功能性NK细胞的发育转变。我们进一步假设，信号通过 我们观察到在AML中被激活的芳香烃受体（AHR）改变Notch信号传导以抑制NK细胞 发展因此，我们的目标是：1）确定在SLTs中Notch被激活以促进细胞凋亡的机制。 NK细胞功能成熟;和2）确定AHR如何调节Notch以拮抗NK细胞成熟。 为了验证这一假设，我们将进行体外培养研究和体内过继转移实验， 从人扁桃体中分离的NK和其他SLT驻留细胞。我们将确定激活的直接基因靶点， NK细胞中的Notch，以确定Notch如何调节NK细胞功能的关键分子的转录。 最后，我们将确定AHR如何调节NK细胞中的Notch信号传导。这个项目的整体意义 将解决有关人类NK细胞成熟调节的相关知识空白， 微环境该项目代表了癌症免疫学的一种新颖和创新的方法，因为它 结合了对一个重要信号通路的机制研究，并试图确定癌症如何 例如AML可以逃避人类免疫系统。成功地完成这些目标将提高我们的 了解NK细胞发育的正常过程，目的是将这些发现应用于 癌症的新型免疫疗法。

PROJECT SUMMARY/ABSTRACT Our long-term goal in this project is to elucidate the mechanisms of human natural killer cell development in order to apply the processes of NK cell biology in the treatment of cancer. Natural killer (NK) cells recognize malignant cells lacking self-MHC molecules on their surface, thus targeting them for perforin-mediated cytotoxicity. NK cells comprise an important role in the innate immune response to malignancy, and indeed cancers such as acute myeloid leukemia (AML) have been shown to have impaired NK cell development and function. Therefore, understanding the yet unknown mechanisms regulating NK cell maturation in both the normal and disease settings will improve translational research efforts for cancer therapy. Our ongoing work investigates NK cell developmental pathways occurring in secondary lymphoid tissues (SLTs; including tonsils and lymph nodes). In our current studies, we observed that activation of the Notch signaling pathway results in a key transition during development from a non-functional phenotype to a functionally mature NK cell. Moreover, we detected constitutive expression of the transcriptionally-active domain of Notch in mature NK cells freshly isolated from tonsils, thus supporting the physiologic importance of Notch in regulating the functional phenotype of mature NK cells. We hypothesize that Notch signaling in the SLT microenvironment regulates the developmental transition from immature to functional NK cells. We further hypothesize that signaling through the aryl hydrocarbon receptor (AHR), which we observe is activated in AML, alters Notch signaling to inhibit NK cell development. Thus our aims are 1) to determine the mechanism by which Notch is activated in SLTs to promote NK cell functional maturation; and 2) to determine how AHR modulates Notch to antagonize NK cell maturation. To test this hypothesis, we will perform in vitro culture studies and in vivo adoptive transfer experiments using NK and other SLT-resident cells isolated from human tonsils. We will identify the direct gene targets of activated Notch in NK cells to determine how Notch regulates the transcription of critical molecules for NK cell function. Finally, we will identify how AHR modulates Notch signaling in NK cells. The overall significance of this project will address a relevant gap in knowledge regarding the regulation of human NK cell maturation in the SLT microenvironment. This project represents a novel and innovative approach to cancer immunology because it combines both mechanistic studies of an important signaling pathway, and also seeks to identify how cancers such as AML can evade the human immune system. Successful completion of these aims will improve our understanding of the normal processes of NK cell development with the goal of applying these discoveries toward novel immune-based therapies for cancer.