INDUCTION OF NF-KB AFTER EXPOSURE OF LYMPHOID CELLS TO SOLUBLE TAX1

淋巴细胞暴露于可溶性 TAX1 后诱导 NF-KB

• 批准号: 3838474
• 负责人: J BRADY
• 金额: --
• 依托单位: DIVISION OF CANCER EPIDEMIOLOGY AND GENETICS
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3838474
• 关键词: gel mobility shift assay; gene induction /repression; genetic regulation; human T cell lymphotropic virus type 1; immunoglobulin genes; phosphoproteins; polymerase chain reaction; tissue /cell culture; transcription factor; tumor necrosis factor beta; virus genetics; virus protein

HTLV-I Tax1, in addition to the protein's role of viral and cellular gene regulation in the infected cell, is released from the infected cell to act as an extracellular cytokine. It has been demonstrated that purified, extracellular Tax1 protein induced the nuclear accumulation of NF-kB binding activity in lymphoid cells. Since HTLV-I infection causes increased levels of lymphotoxin (TNF-beta) and immunoglobulin secretion, the interaction of NF-kB proteins from Tax1- stimulated cells with the TNF-~ and immunoglobulin kappa (Igk) light chain genes has been analyzed. Tax1 induction of NF-kB occurred in the presence of cyclo-heximide. Tax1 stimulation did not result in increased levels of NF-kB or c-rel RNA. These results indicate that new synthesis of NF-kB proteins was not required for induction of NF-kB binding activity. Using the Igk NF-kB binding site as a probe, two distinct NF-kB gel shift complexes were induced by the Tax1 protein. Analysis of the gel shift complexes suggest that they are regulated by distinct inhibitor proteins. The NF-kB proteins that interacted with the consensus NF-kB binding sites in the Igk and TNF-beta promoter were distinct. Tax1 stimulation led to increased levels of TNF-beta and Igk mRNA as measured by reverse transcription and PCR analysis. These results represent the first experimental evidence that extracellular Tax1 can regulate the expression of endogenous cellular genes.

HTLV-I Tax 1除了蛋白质的作用外还有病毒和细胞基因 受感染细胞中的调节，从受感染细胞释放， 作为细胞外细胞因子。 已经证明 纯化的细胞外Tax 1蛋白诱导细胞核积聚， 淋巴样细胞中的NF-kB结合活性。 由于HTLV-I感染导致 增加的光敏素（TNF-β）和免疫球蛋白分泌水平， 来自Tax 1刺激的细胞的NF-kB蛋白与 分析了TNF-α和免疫球蛋白κ（Igk）轻链基因。 Tax 1诱导NF-κ B发生在环己酰亚胺的存在下。 Tax1 刺激不导致NF-κ B或c-rel RNA水平的增加。 这些结果表明NF-kB蛋白质的新合成不是由细胞周期的变化引起的。 诱导NF-kB结合活性所需。 使用Igk NF-kB 结合位点作为探针，两种不同的NF-κ B凝胶位移复合物， 由Tax 1蛋白诱导。 凝胶位移复合物的分析表明， 它们受到不同的抑制蛋白的调控。 的NF-κ B 与NF-kB结合位点相互作用的蛋白质， Igk和TNF-β启动子不同。 Tax 1刺激导致 通过逆转录-聚合酶链反应测定TNF-β和Igk mRNA水平升高 转录和PCR分析。 这些结果代表了第一个 实验证据表明细胞外Tax 1可以调节 内源性细胞基因。