The Role of Met Tyrosine Kinase Signaling in Dendritic Cells for Regulation of Cell Motility, Migration, and Immune Response

Met 酪氨酸激酶信号在树突状细胞中调节细胞运动、迁移和免疫反应的作用

• 批准号: 289105815
• 负责人: Dr. Thomas Hieronymus
• 金额: --
• 依托单位: Institut für Zellbiologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/289105815?language=en
• 关键词: Role; Met; Tyrosine; Kinase; Signaling

Antigen-presenting dendritic cells (DCs) are key regulators of adaptive immune responses and play a crucial role in various inflammatory diseases. Following antigen capture, DCs residing in peripheral tissues, such as intestine and skin, are activated and migrate towards lymphoid organs. We follow the concept that TGF-beta receptor and the Met tyrosine kinase signaling pathways have an antagonistic activity on DC homing in and emigration from peripheral tissues. TGF-beta-signaling is essential to maintain the stationary phenotype of epidermal DCs (Langerhans cells; LCs) by inhibiting their migration. In contrast, by employing a conditional Met-knockout (Metfl/fl) mouse model we recently identified Met-signaling in LCs and dermal DCs as essential for emigration from skin. Signaling by TGF-beta receptors and Met are known to play important roles in controlling epithelial-to-mesenchymal transition (EMT) where Met is a potent inducer of EMT. The main objective in this project is to survey the concept that Met-signaling executes an EMT program in DCs, which is crucial for their development and function. We aim at identifying molecular mechanisms and factors involved in migration regulation of DCs by Met. Global gene and microRNA expression profiling will identify Met target genes in DCs to provide further insight into the cell type specific signal cascade. Furthermore, we will use the Metfl/fl mouse model to confirm Met-signaling specificity. To better understand whether or not these effects are due to post-transcriptional modifications of factors, such as phosphorylation, we will specifically address the Gab1-Shp2-ERK/MAPK signaling cascade on the molecular level and by employing a conditional Gab1-knockout (Gab1fl/fl) mouse model. Changes in motile properties of cells including disassembly of focal adhesions, cytoskeleton remodeling, and the formation of podosomes are recognized as part of the EMT program. Whether Met-signaling is involved in podosome formation or function in DCs is yet unknown and this will be tested using the Metfl/fl mouse model. Complementary, the functional role of signaling pathways and factors on migration, adhesion, and podosome formation assays will be analyzed using kinase inhibitors and siRNA approaches. Finally, we will address the physiological role of Met-signaling in DCs in inflammatory mouse disease models in skin and intestine. Taken together, this research shall reveal whether execution of an EMT program by Met-signaling in DCs represents a crucial mechanism in DC development and function. This may provide novel strategies for treatment of immune-regulated diseases.

抗原呈递树突状细胞（DC）是适应性免疫应答的关键调节因子，在各种炎症性疾病中起着至关重要的作用。抗原捕获后，位于外周组织如肠和皮肤中的DC被激活并向淋巴器官迁移。我们遵循这样的概念，即TGF-β受体和Met酪氨酸激酶信号通路对DC归巢和从外周组织迁移具有拮抗活性。TGF-β信号传导对于通过抑制表皮DC（朗格汉斯细胞; LC）的迁移来维持其稳定表型是必不可少的。相比之下，通过采用条件性Met敲除（Metfl/fl）小鼠模型，我们最近确定了LC和真皮DC中的Met信号传导对于从皮肤迁移是必需的。已知TGF-β受体和Met的信号传导在控制上皮-间充质转化（EMT）中起重要作用，其中Met是EMT的有效诱导剂。本项目的主要目标是调查Met-signaling在DC中执行EMT程序的概念，这对它们的发展和功能至关重要。我们的目的是确定分子机制和因素参与迁移调节的树突状细胞的Met。全局基因和microRNA表达谱将鉴定DC中的Met靶基因，以进一步了解细胞类型特异性信号级联。此外，我们将使用Metfl/fl小鼠模型来确认Met信号传导特异性。为了更好地了解这些效应是否是由于转录后修饰的因素，如磷酸化，我们将具体解决Gab1-Shp2-ERK/MAPK信号级联的分子水平上，并采用条件性Gab1敲除（Gab1fl/fl）小鼠模型。细胞运动特性的改变，包括局部粘连的分解、细胞骨架重塑和足体的形成，被认为是EMT程序的一部分。Met信号传导是否参与DC中的足体形成或功能尚不清楚，这将使用Metfl/fl小鼠模型进行测试。互补的，信号通路和迁移，粘附，和podosome形成测定因子的功能作用将使用激酶抑制剂和siRNA的方法进行分析。最后，我们将讨论在皮肤和肠道炎症小鼠疾病模型中，DCs中Met信号传导的生理作用。两者合计，这项研究将揭示是否执行EMT程序的Met-信号在DC代表一个重要的机制，在DC的发展和功能。这可能为治疗免疫调节疾病提供新的策略。