Suppression of interleukin-2 by the putative endogenous cannabinoid 2-arachidonyl-glycerol is mediated through down-regulation of the nuclear factor of activated T cells
Suppression of interleukin-2 by the putative endogenous cannabinoid 2-arachidonyl-glycerol is mediated through down-regulation of the nuclear factor of activated T cells
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DOI：
10.1124/mol.53.4.676
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发表时间：
1998-04-01
影响因子：
3.6
通讯作者：
Kaminski, NE
中科院分区：
文献类型：
--
作者：
Ouyang, YL;Hwang, SG;Kaminski, NE
2-花生四烯酸甘油（2-Ara-G1）是大麻素受体CB 1和CB 2的内源性配体。最近的免疫功能试验表明，2-Ara-G1具有免疫调节活性。由于几种植物衍生的大麻素抑制白细胞介素-2（IL-2）表达，因此研究了2-Ara-G1调节这种细胞因子的能力。直接添加2-Ara-G1小鼠脾细胞培养物抑制佛波醇-12-肉豆蔻酸酯-13-乙酸酯加离子霉素诱导的IL-2分泌和稳态mRNA表达的剂量依赖性方式。通过用pIL-2-CAT构建体瞬时转染EL4.IL-2细胞测定，2-Ara-G1也产生对IL-2启动子活性的显著抑制。5、10、20和50 μ M的2-Ara-G1分别抑制佛波醇-12-肉豆蔻酸酯-13-乙酸酯加离子霉素诱导的IL-2启动子活性18%、28%、39%和54%。为了进一步表征2-Ara-G1对IL-2的转录调节机制，在小鼠脾细胞中通过电泳迁移率变动分析评估转录因子、活化T细胞核因子（NF-AT）、B细胞中免疫球蛋白κ链核因子（NF-kappa B/Rel）、激活蛋白-1（AP-1）、八聚体和cAMP-反应元件结合蛋白的DNA结合活性。此外，在瞬时转染的EL 4. IL-2细胞中使用p（NF-κ B）（3）-CAT、p（NF-AT）（3）-CAT和p（AP-1）（3）-CAT的报告基因表达系统，以确定2-Ara-G1对每种特异性转录因子启动子活性的影响。2-Ara-G1以剂量依赖性方式降低NF-AT结合和启动子活性，并在较小程度上降低NF-κ B/Rel结合和启动子活性。未观察到对八聚体和cAMP反应元件结合活性的显著影响。AP-1 DNA结合活性不被2-Ara-G1抑制，但观察到启动子活性的适度抑制。
2-Arachidonyl-glycerol (2-Ara-G1) recently was identified as a putative endogenous ligand for cannabinoid receptor types CB1 and CB2 by competitive binding. More recent immune function assays demonstrated that 2-Ara-G1 possessed immunomodulatory activity. Because several plant-derived cannabinoids inhibit interleukin-2 (IL-2) expression, 2-Ara-G1 was investigated for its ability to modulate this cytokine. The direct addition of 2-Ara-G1 to mouse splenocyte cultures suppressed phorbol-12-myristate-13-acetate plus ionomycin-induced IL-2 secretion and steady state mRNA expression in a dose-dependent manner. 2-Ara-G1 also produced a marked inhibition of IL-2 promotor activity as determined by transient transfection of EL4.IL-2 cells with a pIL-2-CAT construct. 2-Ara-G1 at 5, 10, 20, and 50 mu M suppressed phorbol-12-myristate-13-acetate plus ionomycin-induced IL-2 promotor activity by 18%, 28%, 39%, and 54%, respectively. To further characterize the mechanism for the transcriptional regulation of IL-2 by 2-Ara-G1, the DNA-binding activity of transcription factors, nuclear factor of activated T cells (NF-AT), nuclear factor for immunoglobulin kappa chain in B cells (NF-kappa B/Rel), activator protein-1 (AP-1), octamer, and cAMP-response element binding protein was evaluated by electrophoretic mobility shift assay in mouse splenocytes. In addition, a reporter gene expression system for p(NF-kappa B)(3)-CAT, p(NF-AT)(3)-CAT, and p(AP-1)(3)-CAT was used in transiently transfected EL4.IL-2 cells to determine the effect of 2-Ara-G1 on promoter activity for each of the specific transcription factors. 2-Ara-G1 reduced both the NF-AT-binding and promoter activity in a dose-dependent manner and, to a lesser degree, NF-kappa B/Rel-binding and promoter activity. No significant effect was observed on octamer-and cAMP-response element-binding activity. AP-1 DNA-binding activity was not inhibited by 2-Ara-G1, but a modest inhibition of promoter activity was observed.