The roles of interaction between adhesion molecules, chemokines and vascular endothelial cells in the pathogenesis of periodontitis

牙周炎是由牙龈卟啉单胞菌等口腔致病菌激活牙菌斑中的免疫成分细胞而引起的慢性炎症性疾病。为了分析慢性炎症的发病机制，我们研究了NK细胞、T细胞和单核细胞等免疫组分细胞活化的信号转导作用，以及这些细胞介导的内皮损伤，从而导致血管损伤。此外，我们研究了fractalkine和RANKL在牙周炎发展中的可能参与。1）分析了NK 3.3细胞中Cbl与衔接蛋白Grb 2和CrkL的酪氨酸磷酸化及其相互作用。我们发现，CrkL协会与大部分的酪氨酸磷酸化的Cbl后，CD2刺激的NK 3.3细胞。与Cbl与Grb 2的组成性结合相反，酪氨酸磷酸化的Cbl仅通过其SH2结构域与CrkL相互作用， ...更多信息 称为CD2刺激。它们的酪氨酸磷酸化强烈表明Cbl与Grb2和CrkL的相互作用可能在CD2介导的NK细胞活化中起关键作用。2)我们发现，衔接蛋白LAT的酪氨酸磷酸化和随后的信号分子，Grb 2，CrkL，Shc和Cbl之间的相互作用可能解释了IL-2刺激和CD 2交联对NK细胞活化的累加效应的分子机制。3)我们发现通过NK细胞活化受体的聚集调节脂筏的完整性，导致LAT与PI 3-K和PLC-γ 1形成复合物，是NK细胞溶解机制所必需的。4)MCP-1、RANTES等趋化因子在T细胞与成纤维细胞的粘附中起重要作用，可能通过增强炎症部位的免疫反应参与牙周炎的发病. Fractalkine在单核细胞和NK细胞损伤血管内皮细胞中的作用：1）Fractalkine可能是单核细胞和内皮细胞之间的粘附分子，而不是趋化因子。2)我们发现，fractalkine可能诱导单核细胞和内皮细胞之间的牢固粘附，不仅通过内在的粘附功能本身，但也通过激活整合素的亲和力，他们的配体。3)提示Fractalkine不仅在NK细胞与内皮细胞的结合中起重要作用，而且在NK细胞介导的内皮细胞损伤中起重要作用，从而可能导致血管损伤. Fractalkine和RANKL在人牙周炎中的表达：在炎症性人牙龈组织的粘膜下血管中已经鉴定出对Fractalkine和RANKL的阳性免疫反应性。这些结果表明，Fractalkine和RANKL是人类牙周炎的发病机制和发展的重要分子。少

Periodontitis is the chronic inflammatory disease caused by immunocomponents cells activated by oral pathologic bacteria such as Porphymonas gingivalis in dental plaque. To analyzes the pathogenic mechanisms of the chronic inflammation, we investigated the signaling roles on the activation of immunocomponents cells, such as NK cell, T cell and monocyte, and the roles on these cells-mediated endothelium damage, which may result in vascular injury. Moreover, we investigated the possible involvement of fractalkine and RANKL in the development of periodontitis.1. The signaling roles in the activation of immunocomponents cells: 1) We analyzed tyrosine phosphorylation and interaction of Cbl with adaptor proteins, Grb2 and CrkL in NK3.3 cells. We revealed that CrkL associates with a large portion of tyrosine phosphorylated Cbl after CD2 stimulation of NK3.3 cells. In contrast to constitutive Cbl association with Grb2, tyrosine phosphorylated Cbl interacted with CrkL via its SH2 domain only af … More ter CD2 stimulation. Their tyrosine phosphorylation strongly suggests that interactions of Cbl with Grb2 and CrkL may play pivotal roles in CD2-mediated NK cell activation. 2) We revealed that tyrosine phosphorylation of adaptor protein LAT and consequent interactions between signaling molecules, Grb2, CrkL, Shc and Cbl might explain that the molecular mechanisms of the additive effects of IL-2 stimulation and CD2 cross-linking on NK cell activation. 3) We found that modulation of lipid raft integrity by aggregation of NK cell activating receptors, which leaded to the formation of complexes of LAT with PI3-K and PLC-γ1, was essential for the NK cell lytic mechanisms. 4) We also revealed that some chemokines, such as MCP-1 and RANTES, had an important role in the adhesion of T cells to fibroblasts, which might be involved in the pathogenesis of periodontitis by enhancing immunologic reaction at the inflammatory sites.2. The roles of fractalkine in vascular endothelial cell injury by monocytes and NK cells: 1) We revealed that fractalkine might function as an adhesion molecule between monocytes and endothelial cells rather than as a chemotactic factor. 2) We found that fractalkine might induce firm adhesion between monocytes and endothelial cells not only through an intrinsic adhesion function itself, but also through activation of integrin avidity for their ligands. 3) We suggest that fractalkine plays an important role not only in the binding of NK cells to endothelial cells, but also in NK cell-mediated endothelial cell damage, which may result in vascular injury.3. Expression of fractalkine and RANKL in human periodontitis: Positive immunoreactivities to fractalkine and RANKL have been identified in submucosal vessels of inflammatory human gingival tissue. These results suggest that fractalkine and RANKL are important molecules in the pathogenesis and progression of human periodontitis. Less