Patestos N P, Haegeman G, Vandevoorde V, Fiers W
Laboratory of Molecular Biology, Gent University, Belgium.
Biochimie. 1993;75(11):1007-18. doi: 10.1016/0300-9084(93)90153-j.
After treatment of L929 cells, a murine fibrosarcoma line, with tumor necrosis factor (TNF), a nuclear kappa B-like transcription factor is rapidly induced as identified by gel shift mobility assays using the kappa B-responsive sequence of the immunoglobulin or interleukin-6 (IL-6) genes as a DNA probe. When induction was carried out under conditions of increased or decreased cytotoxicity, which correlates with altered IL-6 gene expression, nuclear factor kappa B (NF-kappa B) activation was also demonstrated, but the abundance of the protein/DNA complex observed remained unchanged. Also activation of NF-kappa B as a function of time following TNF treatment did not reveal a correlation between the abundance of the protein/DNA complex and the TNF-induced IL-6 mRNA levels. Moreover, in L929 cells resistant to TNF cytotoxicity, the kappa B-like factor still became fully activated by TNF, although the IL-6 gene was only marginally expressed. In conclusion, discrepancies between the abundance of the activated NF-kappa B-like factor and the IL-6 mRNA production upon treatment with TNF indicate that (an) additional transcription factor(s) and/or (a) regulating mechanism(s) is (are) necessary for fine regulation of the level of IL-6 gene expression in response to cytokine stimulation.
用肿瘤坏死因子（TNF）处理小鼠纤维肉瘤细胞系L929细胞后，通过凝胶迁移率变动分析鉴定发现，一种类核κB转录因子被迅速诱导，该分析使用免疫球蛋白或白细胞介素-6（IL-6）基因的κB反应序列作为DNA探针。当在细胞毒性增加或降低的条件下进行诱导时（这与IL-6基因表达的改变相关），也证明了核因子κB（NF-κB）的激活，但观察到的蛋白质/DNA复合物的丰度保持不变。TNF处理后NF-κB的激活随时间变化的情况也未显示蛋白质/DNA复合物的丰度与TNF诱导的IL-6 mRNA水平之间存在相关性。此外，在对TNF细胞毒性具有抗性的L929细胞中，类κB因子仍能被TNF完全激活，尽管IL-6基因仅少量表达。总之，TNF处理后活化的类NF-κB因子的丰度与IL-6 mRNA产生之间的差异表明，为了精细调节IL-6基因表达水平以响应细胞因子刺激，需要额外的转录因子和/或调节机制。
