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Molecular mechanisms of immune cell trafficking

免疫细胞运输的分子机制

基本信息

批准号：
17209018
负责人：
KINASHI Tatsuo
金额：
$ 33.03万
依托单位：
Kansai Medical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17209018/
关键词：
integrin Rap 1 chemokines lymphocyte RAPL cell adhesion lymphocyte homing

项目摘要

To elucidate the regulatory mechanisms of integrin adhesion receptors by the small GTPase Rap1 and its effector molecule RAPL, we isolated Mst1, which belongs to the ste20-like kinase family. Mst1 was associated with and activated by RAPL through its coiled-coil region. Mst1 kinase activity was stimulated by activated Rap1 and also by chemokines and TCR ligation. However, in RAPL-deficient lymphocytes, Mst1 was hardly activated by chemokines and TCR ligation, indicating that Mst1 is activated by these stimulation in a RAPL-dependent manner. Overexpression of Mst1 led to development of the leading edge and uropod, and LFA-1 clustering in the leading edge, resulting in increased adhesion by LFA-1, all of which required the Mst1 kinase activity. Conversely, Mst1 knockdown by shRNA impaired cell polarity development and augmentation of adhesion by chemokines and TCR ligation. These results indicate that Mst1 is a critical downstream protein kinase responsible for cell polarity development … More and LFA-1 regulation triggered by chemokines and the TCR. In RAPL-deficient mice, the T and B lymphocyte numbers in peripheral lymph nodes was reduced due to defective lymphocyte homing. In vitro flow adhesion assays with HEV-like endothelial cells and intravital microscopic analysis of lymphocyte trafficking indicate that Rap1 plays a critical role in arrest from rolling, and RAPL is required for firm adhesion by LFA-1 and α4β7. The β2 and αL cytoplasmic domains is involved in arrest and firm adhesion, respectively. Furthermore, intravital two-photon microscopy revealed that RAPL-deficient T and B cells moved at slower velocities with reduced displacement within lymph nodes. Taken together, these studies demonstrate that the Rap1-RAPL signaling regulates lymphocyte cell polarity and LFA-1 activity through Mst1 and control lymphocyte adhesion to endothelial cells and interstitial migration within lymph nodes in vivo. Based on these functions, we are currently examining lymphocyte growth and differentiation in mice genetically engineered on RAPL and Mst1 loci in order to clarify the relationship of lymphocyte adhesion with cell growth/differentiation and immune diseases. Less

为了阐明小GT受体Rap 1及其效应分子RAPL对整合素粘附受体的调节机制，我们分离了属于ste 20样激酶家族的Mst 1。Mst 1通过其卷曲螺旋区与RAPL相关并被RAPL激活。Mst 1激酶活性被激活的Rap 1刺激，也被趋化因子和TCR连接。然而，在RAPL缺陷型淋巴细胞中，Mst 1几乎不被趋化因子和TCR连接激活，表明Mst 1以RAPL依赖性方式被这些刺激激活。Mst 1的过表达导致前缘和尾足的发育，LFA-1聚集在前缘，导致LFA-1的粘附增加，所有这些都需要Mst 1激酶活性。相反，Mst 1敲低的shRNA损害细胞极性的发展和增强的粘附趋化因子和TCR连接。这些结果表明，Mst 1是一个关键的下游蛋白激酶，负责细胞极性的发展 ...更多信息以及由趋化因子和TCR触发的LFA-1调节。在RAPL缺陷型小鼠中，由于淋巴细胞归巢缺陷，外周淋巴结中的T和B淋巴细胞数量减少。HEV样内皮细胞的体外流动粘附试验和淋巴细胞运输的活体显微镜分析表明，Rap 1在阻止滚动中起关键作用，而RAPL是LFA-1和α4β7牢固粘附所必需的。β2和αL胞质结构域分别参与停滞和牢固粘附。此外，活体双光子显微镜显示，RAPL缺陷的T和B细胞移动速度较慢，淋巴结内的位移减少。总之，这些研究表明，Rap 1-RAPL信号调节淋巴细胞极性和LFA-1活性通过Mst 1和控制淋巴细胞粘附内皮细胞和淋巴结内的间质迁移在体内。基于这些功能，我们目前正在研究淋巴细胞的生长和分化的小鼠基因工程的RAPL和Mst 1位点，以澄清淋巴细胞粘附与细胞生长/分化和免疫疾病的关系。少