Proinflammatory cytokines induce liver and activation-regulated chemokine/macrophage inflammatory protein-3α/CCL20 in mucosal epithelial cells through NK-κB
Proinflammatory cytokines induce liver and activation-regulated chemokine/macrophage inflammatory protein-3α/CCL20 in mucosal epithelial cells through NK-κB
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DOI：
10.1093/intimm/13.10.1255
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发表时间：
2001-10-01
影响因子：
4.4
通讯作者：
Yoshie, O
中科院分区：
文献类型：
--
作者：
Fujiie, S;Hieshima, K;Yoshie, O
肝脏和活化调节趋化因子（LARC）/CCL 20由表面衬里上皮和表皮细胞表达，并且可能通过吸引未成熟树突状细胞、效应记忆T细胞和B细胞经由CCR 6来连接先天性和获得性免疫。在这里，我们研究了LARC在上皮型细胞中表达的机制。IL-1 β或肿瘤坏死因子（TNF）-α在肠细胞系Caco-2和T84中强烈诱导LARC mRNA，而两者对HEK 293 T细胞均有效。用IL-1 α或TNF-α处理后，在BALB/c小鼠的肠上皮中也证实了LARC的诱导。使用鼠LARC启动子-报告基因构建体的瞬时转染测定鉴定了Caco-2和293 T细胞中IL-1 β或TNF-α诱导的启动子活化所必需的区域。使用定点突变，我们证明了位于转录起始位点上游-96和-87 bp之间的NF-κ B位点对于Caco-2和293 T细胞中IL-1 β或TNF-α诱导的启动子激活是必要的和足够的。电泳迁移率变动分析表明，在用IL-1 β和TNF-α处理后，NF-κ B的p50/p65异源二聚体和p65同源二聚体在293 T细胞中结合于该位点，并且在用IL-1 β处理后，p50/p65异源二聚体在Caco-2细胞中结合于该位点。组成型活性p65的共表达强烈激活了293 T和Caco-2细胞中携带完整NF-κ B位点的启动子构建体。总的来说，肠上皮型细胞中的LARC表达由促炎细胞因子如IL-1和TNF-α诱导，主要通过NF-κ B的活化。
Liver and activation-regulated chemokine (LARC)/CCL20 is expressed by surface-lining epithelial and epidermal cells, and is likely to link innate and acquired immunity by attracting immature dendritic cells, effector memory T cells and B cells via CCR6. Here we examined the mechanism of LARC expression in epithelial-type cells. Either IL-1 beta or tumor necrosis factor (TNF)-alpha strongly induced LARC mRNA in intestinal cell lines Caco-2 and T84, while both were effective on HEK 293T cells. Induction of LARC was also demonstrated in the intestinal epithelium of BALB/c mice upon treatment with IL-1 alpha or TNF-alpha. Transient transfection assays using murine LARC promoter-reporter constructs identified a region essential for IL-1 beta, or TNF-alpha -induced promoter activation in Caco-2 and 293T cells. Using site-directed mutagenesis, we demonstrated that an NF-kappaB site located between -96 and -87 bp upstream from the transcriptional start site was both necessary and sufficient for IL-1 beta- or TNF-alpha -induced promoter activation in Caco-2 and 293T cells. Electrophoretic mobility shift assays demonstrated that p50/p65 heterodimer and p65 homodimer of NF-kappaB bound to this site in 293T cells upon treatment with IL-1 beta and TNF-alpha, and p50/p65 heterodimer bound to this site in Caco-2 cells upon treatment with IL-1 beta. Co-expression of constitutively active p65 strongly activated the promoter construct carrying the intact NF-kappaB site in 293T and Caco-2 cells. Collectively, LARC expression in intestinal epithelial-type cells is induced by proinflammatory cytokines such as IL-1 and TNF-alpha primarily through activation of NF-kappaB.