Unraveling the plasticity and tumor-promoting role of neutrophils as a function of tumor heterogeneity

肿瘤相关中性粒细胞（TAN）是实体瘤（如黑色素瘤）免疫浸润的重要组成部分。利用其主动迁移的能力，TAN被募集到黑色素瘤的附近和中心。已经表明，这些细胞表现出巨大的功能异质性。一方面，它们可以通过许多机制促进肿瘤生长增加、更具侵袭性的转移和对肿瘤治疗的耐药性的发展。另一方面，TAN也被描述为发挥显著的肿瘤控制。由于迄今为止缺乏合适的临床前模型，这种不同功能（促肿瘤与抗肿瘤）的潜在机制尚未得到很好的阐明。因此，目前还不可能选择性地影响TAN以改善对靶向肿瘤治疗的反应。在本项目中，将使用新生成的实验系统和主要患者材料在转移性黑色素瘤的背景下研究TAN。为此，使用了具有移植或自发发展的黑色素瘤的创新小鼠模型，其中TAN同时被遗传标记以使其可见。移植的肿瘤在对治疗的敏感性方面显示出明确的可塑性。这种可塑性也反映在自发发展的模型中。在第一个资助阶段，我们能够证明有黑色素瘤对免疫检查点阻断剂有抗性，但通过去除TAN而大大减缓了生长。我们最初使用复杂蛋白质组学阐明了TAN的功能和分子身份。在活体显微镜直接在肿瘤内部的帮助下，我们能够分析TAN和肿瘤的相互作用，并在体外筛选中获得关于如何控制TAN迁移到肿瘤中的初步信息。在第二个资助阶段，我们现在希望详细阐明TAN的分子特征，不仅在黑色素瘤中，而且在FOR的其他肿瘤实体中。此外，我们想了解TAN如何支持肿瘤逃避免疫治疗，以及存在哪些临床适用的抑制剂可以阻止TAN迁移到肿瘤中。此外，一个目标是使用条形码来找出在免疫治疗抗性和TAN非依赖性持续细胞中发展的肿瘤细胞特征。其目的是，一方面，以确定可能的新的治疗概念，目标的TAN的调制，另一方面，定义新的TAN相关的生物标志物，将允许预测在未来的治疗的有效性。此外，在PhenoTIME的框架内，对其他肿瘤实体获得的见解的有效性有待澄清。

Tumor-associated neutrophil granulocytes (TAN) form an essential component of the immunological infiltrate of solid tumors, such as melanoma. Taking advantage of their ability to actively migrate, TAN are recruited to the vicinity and center of melanomas. It has been shown that these cells exhibit enormous functional heterogeneity. On the one hand, they can contribute to increased tumor growth, more aggressive metastasis and development of resistance to tumor therapies through a number of mechanisms. On the other hand, TANs have also been described that exert significant tumor control. Due to the lack of suitable preclinical models to date, the underlying mechanisms of this different functionality (pro- versus anti-tumor) are not well elucidated. Thus, it is not yet possible to selectively influence TAN to improve the response to targeted tumor therapy. In this project, TAN will be investigated in the context of metastatic melanoma using newly generated experimental systems and primary patient material. For this purpose, innovative mouse models with transplanted or spontaneously developing melanomas are used, in which the TAN are simultaneously genetically labeled to make them visible. The transplanted tumors show a defined plasticity in terms of sensitivity to therapies. This plasticity is also reflected in the spontaneously developing models. In the first funding phase, we were able to show that there are melanomas that are resistant to immune checkpoint blockers but are strongly slowed down in growth by removal of TAN. We initially clarified the functional and molecular identity of TAN using complex proteomics. With the help of intravital microscopy directly inside the tumor, we were able to analyze the interaction of TAN and tumors and gain initial information in an in vitro screen on how the migration of TAN into the tumors is controlled. In the second funding phase, we now want to clarify the molecular characteristics of TAN in detail, not only in melanoma, but also in other tumor entities of the FOR. Furthermore, we want to understand how TAN support tumors in escaping from immunotherapies and which clinically applicable inhibitors exist that can prevent the migration of TAN into tumors. In addition, one goal is to use barcoding to find out which tumor cell characteristics develop in immunotherapy-resistant and TAN-independent persister cells. The aim is, on the one hand, to identify possible new therapeutic concepts that target the modulation of TAN and, on the other hand, to define new TAN-related biomarkers that will allow prediction of the effectiveness of a therapy in the future. Furthermore, within the framework of PhenoTImE, the validity of the insights gained for other tumor entities is to be clarified.