Chemokines Induce Wnt-Frizzled Gene Expression in Human T Cells

趋化因子已被证明在体外和体内诱导和指导人和啮齿动物白细胞的粘附、趋化、活化和脱粒。CXCL 12和CCL 19是两种重要的趋化因子，在正常和炎症条件下调节T细胞运动和活化。尽管有许多研究趋化因子功能的报道，但对其中涉及的转录事件知之甚少。在这里，我们对CXCL 12处理的T细胞进行了微阵列分析，发现Wnt蛋白家族在CXCL 12处理期间显著上调。通过实时PCR和Western分析证实这些结果表明，在CXCL 12刺激期间，Wnt 5A和非经典Wnt通路的其他成员的表达特异性上调，而β-连环蛋白和经典Wnt家族成员选择性下调。发现Wnt 5A通过蛋白激酶C（PKC）的活化增强通过CXCL 12-CXCR 4轴的信号传导。此外，我们的数据显示，Wnt 5A表达是介导响应CXCL 12的定向T细胞迁移所必需的，并且用重组Wnt 5A处理人T细胞使T细胞对CXCL 12诱导的迁移敏感。此外，Wnt 5A的表达也需要CXCR 4的持续表达，无论是转录还是转录。使用EL 4胸腺瘤转移作为T细胞迁移模型在体内进一步支持这些结果。总之，这些数据首次证明Wnt 5A是人和鼠T细胞中CXCL 12-CXCR 4信号传导和迁移的关键介体。 有趣的是，我们还发现Wnt 10A在CCL 19趋化性和维持T细胞上CCR 7表达中起作用。 这些发现可能揭示了各种趋化因子与Wnt受体和配体之间的新型合作信号网络，该网络可能控制细胞极化和定向迁移。 此外，我们目前还在验证和表征几个额外的基因家族，这些基因家族在迁移后在T细胞中高度表达，以响应或简单地刺激CXCL 12，CCL 19，gp 120和HIV-1病毒。此外，脂筏在趋化因子生物学和HIV感染性中的作用也正在使用微阵列分析进行检查。 更好地了解不同的转录信号诱导的各种趋化因子受体的连接可能提供一种手段来解剖这些化学引诱剂诱导细胞迁移和激活的途径，以及任何主机的转录信号在HIV的进入和复制的重要。

Chemokines have been shown to induce and direct adhesion, chemotaxis, activation, and degranulation of human and rodent leukocytes both in vitro and in vivo. CXCL12 and CCL19 are two important chemokines that regulate T cell motility and activation under normal and inflammatory conditions. Despite numerous reports examining the function of chemokines, little is known about the transcriptional events involved therein. Here, we performed microarray analysis on CXCL12- treated T-cells, and found that the Wnt family of proteins was significantly upregulated during CXCL12 treatment. Confirmation of these results by real-time PCR and Western analysis revealed that the expression of Wnt5A and other members of the non-canonical Wnt pathway were specifically upregulated during CXCL12 stimulation, while -catenin and canonical Wnt family members were selectively downregulated. Wnt5A was found to augment signaling through the CXCL12-CXCR4 axis via the activation of protein kinase C (PKC). Moreover, our data has revealed that Wnt5A expression is required to mediate directional T-cell migration in response to CXCL12, and that the treatment of human T-cells with recombinant Wnt5A sensitized T-cells to CXCL12-induced migration. Furthermore,Wnt5A expression was also required for the sustained expression of CXCR4, both transcriptionally and translationally. These results were further supported in vivo using EL4 thymoma metastasis as a model of T-cell migration. Together, these data demonstrate, for the first time, that Wnt5A is a critical mediator in CXCL12-CXCR4 signaling and migration in human and murine T cells. Interestingly, we also found that Wnt10A plays a role in CCL19 chemotaxis and in the maintenance of CCR7 expression on T cells. These findings may reveal a novel cooperative signaling network between various chemokine and Wnt receptors and ligands that may control cell polarization and directional migration. Moreover, we are also currently verifying and characterizing several additional gene families that are highly expressed in T cells after migration in response to or simply stimulation with CXCL12, CCL19, gp120 and HIV-1 virus. Moreover, the role of lipid rafts in chemokine biology and HIV infectivity are also under examination using microarray analysis. A greater understanding of the transcriptional signals differentially induced by the ligation of various chemokine receptors may provide a means to dissect the pathways by which these chemoattractants induce cell migration and activation as well as any host transcriptional signals important in HIV entry and replication.