Phosphorylation of Leukocyte PECAM and Its Association with Detergent-Resistant Membranes Regulate Transendothelial Migration
Phosphorylation of Leukocyte PECAM and Its Association with Detergent-Resistant Membranes Regulate Transendothelial Migration
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DOI：
10.4049/jimmunol.1001305
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发表时间：
2010-08-01
影响因子：
4.4
通讯作者：
Muller, William
中科院分区：
文献类型：
--
作者：
Florey, Oliver;Durgan, Joanne;Muller, William
白细胞穿过内皮细胞的迁移是机体对感染和炎症反应的关键步骤。内皮细胞PECAM和白细胞PECAM之间的嗜同性相互作用是这个过程所必需的。PECAM参与在内皮细胞中触发的分子事件已得到很好的表征;然而，白细胞PECAM的功能仍有待阐明。为了研究这一点，我们首先使用抗PECAM抗体阻断白细胞的迁移，然后特异性激活白细胞PECAM。这足以克服阻断并促进迁移，表明白细胞PECAM的积极信号传导作用。与此一致，我们发现白细胞PECAM的连接诱导其胞质尾区上两个酪氨酸残基的磷酸化。通过进行RNA干扰拯救实验，我们证明了这些磷酸化事件是不可缺少的跨内皮迁移。最后，我们表明，白细胞PECAM易位到洗涤剂抗性膜（DRM）在轮回。位于DRM中的PECAM显示磷酸化减少，并且不支持迁移。总之，这些数据支持白细胞PECAM的参与诱导其瞬时酪氨酸磷酸化和诱导下游信号，驱动轮回的模型。然后，这些信号在PECAM易位至DRM后下调。免疫学杂志，2010，185：1878-1886。
Leukocyte migration across the endothelial lining is a critical step in the body's response to infection and inflammation. The homophilic interaction between endothelial PECAM and leukocyte PECAM is essential for this process. The molecular events that are triggered in the endothelial cell by PECAM engagement have been well characterized; however, the function of leukocyte PECAM remains to be elucidated. To study this, we first blocked leukocyte transmigration using anti-PECAM Ab and then specifically activated leukocyte PECAM. This was sufficient to overcome the block and promote transmigration, suggesting an active signaling role for leukocyte PECAM. Consistent with this, we found that ligation of leukocyte PECAM induces phosphorylation of two tyrosine residues on its cytoplasmic tail. By performing RNA interference-rescue experiments, we demonstrate that these phosphorylation events are indispensable for transendothelial migration. Finally, we show that leukocyte PECAM translocates to a detergent-resistant membrane (DRM) during transmigration. PECAM localized in DRMs displays reduced phosphorylation and does not support transmigration. Together, these data support a model whereby engagement of leukocyte PECAM induces its transient tyrosine phosphorylation and induction of downstream signals that drive transmigration. These signals are then downregulated following PECAM translocation to DRMs. The Journal of Immunology, 2010, 185: 1878-1886.