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

为了通过小的GTPase RAP1及其效应分子RAPL阐明整联蛋白粘合剂受体的调节机制，我们分离了属于Ste20样激酶家族的MST1。 MST1与Rapl通过其盘绕螺旋区域相关联并激活。激活的RAP1以及趋化因子和TCR连接刺激MST1激酶活性。然而，在Rapl缺陷型淋巴细胞中，MST1几乎不会被趋化因子和TCR连接激活，表明MST1被这些刺激以Rapl依赖性方式激活。 MST1的过表达导致前缘和uropod的发展，并在前缘中簇中LFA-1聚类，从而导致LFA-1的粘合剂增加，所有这些都需要MST1激酶活性。相反，shRNA敲除细胞极性发展和趋化因子和TCR连接的粘合剂增强。这些结果表明，MST1是负责细胞极性发展的关键下游蛋白激酶……更多和LFA-1调节是由趋化因子和TCR触发的。在RAPL缺乏小鼠中，由于淋巴细胞寄养缺陷，外周淋巴细胞淋巴结中的T和B淋巴细胞数减少了。体外流动的粘合剂用HEV样内皮细胞和淋巴细胞运输的插入显微镜分析表明，RAP1在滚动中的逮捕中起着至关重要的作用，而LFA-1和α4β7的粘合剂需要RAPL。 β2和αL细胞质结构域分别参与了停滞和粘合剂。此外，插入的两光子显微镜表明，Rapl缺陷型T和B细胞以较慢的速度移动，淋巴结内部位移降低。综上所述，这些研究表明，Rap1-apl信号传导通过MST1调节淋巴细胞细胞极性和LFA-1活性，并控制体内淋巴结淋巴结内的内皮细胞和间质迁移。基于这些功能，我们目前正在研究在RAPL和MST1局部进行的淋巴细胞生长和分化，以阐明淋巴细胞粘合剂与细胞生长/分化和免疫疾病的关系。较少的