Transcriptional activation of the human TNF-alpha promoter by superantigen in human monocytic cells: role of NF-kappa B.
Transcriptional activation of the human TNF-alpha promoter by superantigen in human monocytic cells: role of NF-kappa B.
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DOI：
10.4049/jimmunol.155.2.902
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发表时间：
1995-07
影响因子：
4.4
通讯作者：
N. Trede;A. Tsytsykova;T. Chatila;A. Goldfeld;R. Geha
中科院分区：
文献类型：
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作者：
N. Trede;A. Tsytsykova;T. Chatila;A. Goldfeld;R. Geha
我们研究了超抗原葡萄球菌肠毒素A（SEA）在人前单核细胞系THP-1中对人TNF-α基因的转录激活。来自SEA刺激的THP-1细胞的核蛋白与kappa 3强烈结合，kappa 3是在TNF-α基因的5'调节区发现的三个推定的NF-κ B结合位点（kappa 1-kappa 3）中的最近端，但仅与kappa 1弱结合，kappa 1是NF-κ B结合位点的最远端，并且显示不与kappa 2结合。kappa 3-核蛋白复合物的迁移率与核蛋白和共有NF-κ B序列之间形成的复合物的迁移率相同。此外，5'和3'突变体的kappa 3不能取代kappa 3的结合，这表明SEA诱导的kappa 3结合复合物具有NF-κ B的特征。使用针对NF-κ B亚基p50和p65的Ab的研究表明，p50和p65都与κ 3序列结合。报告基因分析表明，kappa 3（-99至-89 bp）的缺失和kappa 3序列中3个5'鸟嘌呤碱基的点突变降低了SEA和LPS对TNF-α启动子的诱导作用。这些结果表明超抗原诱导人单核细胞中的NF-κ B，并提示NF-κ B与TNF-α启动子的κ 3位点的结合在超抗原对TNF-α基因的转录激活中起重要作用。
We have studied the transcriptional activation of the human TNF-alpha gene by the superantigen staphylococcal enterotoxin A (SEA) in the human premonocytic cell line THP-1. Nuclear proteins from SEA-stimulated THP-1 cells bound strongly to kappa 3, the most proximal of three putative NF-kappa B binding sites (kappa 1-kappa 3) found in the 5' regulatory region of the TNF-alpha gene, but only weakly to kappa 1, the most distal of the NF-kappa B binding sites, and showed no binding to kappa 2. The mobility of the kappa 3-nucleoprotein complex was identical to that of complexes formed between nuclear proteins and the consensus NF-kappa B seuqence. Moreover, both 5' and 3' mutants of kappa 3 were unable to displace kappa 3 binding, suggesting that the kappa 3 binding complex induced by SEA has the characteristics of NF-kappa B. Studies using Abs directed against the NF-kappa B subunits p50 and p65 suggested that both p50 and p65 bind to the kappa 3 sequence. Reporter gene assays showed that deletion of kappa 3 (-99 to -89 bp) and point mutation of the three 5' guanine bases in the kappa 3 sequence reduced the inducibility of the TNF-alpha promoter by SEA and LPS. These results indicate that superantigen induces NF-kappa B in human monocytic cells and suggest that binding of NF-kappa B to the kappa 3 site of the TNF-alpha promoter plays an important role in the transcriptional activation of the TNF-alpha gene by superantigen.