Scandella Elke, Men Ying, Legler Daniel F, Gillessen Silke, Prikler Ladislav, Ludewig Burkhard, Groettrup Marcus
Department of esearch, Cantonal Hospital St Gallen, Switzerland.
Blood. 2004 Mar 1;103(5):1595-601. doi: 10.1182/blood-2003-05-1643. Epub 2003 Oct 30.
The control of dendritic cell (DC) migration is pivotal for the initiation of cellular immune responses. When activated with inflammatory stimuli, the chemokine receptor CCR7 is up-regulated on DCs. Activated DCs home to lymphoid organs, where the CCR7 ligands CCL19 and CCL21 are expressed. We previously found that human monocyte-derived DCs (MoDCs) exclusively migrated to CCL19 and CCL21 when matured in the presence of prostaglandin (PG) E2. Because PGE2 did not alter CCR7 cell surface expression, we examined whether PGE2 may exert its effect by coupling CCR7 to signal transduction modules. Indeed, stimulation with CCR7 ligands led to enhanced phosphatidylinositol-3-kinase-mediated phosphorylation of protein kinase B when MoDCs were matured in the presence of PGE2. Moreover, CCL19/CCL21-induced intracellular calcium mobilization in MoDCs occurred only when PGE2 was present during maturation. MoDC migration to CCL19 and CCL21 was dependent on phospholipase C and intracellular calcium flux but not on phosphatidylinositol-3 kinase. Hence, our data provide insight into CCL19/CCL21-triggered signal transduction pathways and identify a novel function for PGE2 in controlling the migration of mature MoDCs by facilitating CCR7 signal transduction.
树突状细胞(DC)迁移的控制对于细胞免疫反应的启动至关重要。当受到炎症刺激激活时,趋化因子受体CCR7在DC上上调。活化的DC归巢至表达CCR7配体CCL19和CCL21的淋巴器官。我们之前发现,人单核细胞衍生的DC(MoDC)在前列腺素(PG)E2存在下成熟时仅迁移至CCL19和CCL21。由于PGE2不会改变CCR7的细胞表面表达,我们研究了PGE2是否可能通过将CCR7与信号转导模块偶联来发挥其作用。实际上,当MoDC在PGE2存在下成熟时,用CCR7配体刺激会导致磷脂酰肌醇-3-激酶介导的蛋白激酶B磷酸化增强。此外,仅当成熟过程中存在PGE2时,CCL19/CCL21诱导的MoDC细胞内钙动员才会发生。MoDC向CCL19和CCL21的迁移依赖于磷脂酶C和细胞内钙通量,但不依赖于磷脂酰肌醇-3激酶。因此,我们的数据为CCL19/CCL21触发的信号转导途径提供了见解,并确定了PGE2通过促进CCR7信号转导来控制成熟MoDC迁移的新功能。