Hoeck J, Woisetschläger M
Department of Allergic Diseases, Novartis Research Institute, Vienna, Austria.
J Immunol. 2001 Sep 15;167(6):3216-22. doi: 10.4049/jimmunol.167.6.3216.
Allergic inflammatory conditions such as asthma are characterized by an accumulation of eosinophils at sites of inflammation. Eotaxin-3/CCL26 is a member of the family of CC chemokines, which are known to be potent chemoattractants for eosinophils. This chemokine was shown to be up-regulated by IL-4 and IL-13 in endothelial cells. This study demonstrates that eotaxin-3 transcription and eotaxin-3 protein expression are stimulated by IL-4 and IL-13 in a time- and dose-dependent fashion in human dermal fibroblasts. In contrast to eotaxin-1/CCL11, TNF-alpha could not act as inducer on its own nor did it synergize with IL-4. The activities of eotaxin-3 promoter luciferase constructs were significantly increased by IL-4 and IL-13 in human dermal fibroblasts. This effect was mediated by a binding site for the transcription factor STAT6 in the eotaxin-3 promoter sequence. Mutations in the STAT6 binding site abrogated up-regulation of eotaxin-3 promoter activity. In STAT6-defective human embryonic kidney 293 cells, the wild-type luciferase construct, but not the STAT6 binding mutant, was inducible by IL-4 only upon cotransfection of STAT6 expression vector. In addition, eotaxin-3 protein was detectable in the supernatants of STAT6-transfected human embryonic kidney 293 cells upon IL-4 or IL-13 stimulation. In the same experiments, TNF-alpha induced activation of the monocyte chemoattractant protein-1/CCL2 gene was independent of STAT6 transfection. These results indicate that IL-4 and IL-13 activate eotaxin-3 gene expression in a STAT6-dependent fashion. Although both eotaxin-1 and -3 are regulated by this transcription factor, the response of the eotaxin-3 gene to TNF-alpha stimulation appears to be different.
诸如哮喘之类的变应性炎症性疾病的特征是嗜酸性粒细胞在炎症部位积聚。嗜酸性粒细胞趋化因子-3/CCL26是CC趋化因子家族的成员，已知其是嗜酸性粒细胞的有效趋化剂。该趋化因子在内皮细胞中被白细胞介素-4和白细胞介素-13上调。本研究表明，在人皮肤成纤维细胞中，嗜酸性粒细胞趋化因子-3的转录和嗜酸性粒细胞趋化因子-3蛋白表达受到白细胞介素-4和白细胞介素-13的刺激，呈时间和剂量依赖性。与嗜酸性粒细胞趋化因子-1/CCL11不同，肿瘤坏死因子-α自身不能作为诱导剂，也不能与白细胞介素-4协同作用。在人皮肤成纤维细胞中，白细胞介素-4和白细胞介素-13显著增加了嗜酸性粒细胞趋化因子-3启动子荧光素酶构建体的活性。这种效应是由嗜酸性粒细胞趋化因子-3启动子序列中转录因子STAT6的结合位点介导的。STAT6结合位点的突变消除了嗜酸性粒细胞趋化因子-3启动子活性的上调。在STAT6缺陷的人胚肾293细胞中，仅在共转染STAT6表达载体后，野生型荧光素酶构建体而非STAT6结合突变体才能被白细胞介素-诱导。此外，在白细胞介素-4或白细胞介素-13刺激后，在转染STAT6的人胚肾293细胞的上清液中可检测到嗜酸性粒细胞趋化因子-3蛋白。在相同实验中，肿瘤坏死因子-α诱导的单核细胞趋化蛋白-1/CCL2基因的激活与STAT6转染无关。这些结果表明，白细胞介素-4和白细胞介素-13以STAT6依赖性方式激活嗜酸性粒细胞趋化因子-3基因表达。虽然嗜酸性粒细胞趋化因子-1和-3均受该转录因子调节，但嗜酸性粒细胞趋化因子-3基因对肿瘤坏死因子-α刺激的反应似乎不同。
