Distribution and behavior of the Ah receptor in murine T lymphocytes.
Distribution and behavior of the Ah receptor in murine T lymphocytes.
复制标题
Ah 受体在小鼠 T 淋巴细胞中的分布和行为。
DOI：
10.1006/taap.1996.0126
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发表时间：
1996
影响因子：
3.8
通讯作者：
Kerkvliet,NI
中科院分区：
文献类型：
--
作者：
Lawrence,BP;Leid,M;Kerkvliet,NI
C57 Bl/6小鼠暴露于2，3，7，8-四氯二苯并-p-二恶英（TCDD）可引起细胞介导和体液免疫的抑制。对Ah基因座同源小鼠的研究表明，这种抑制是由芳烃受体（AhR）介导的。Ah受体是一种配体依赖性转录因子，已在肝细胞中得到充分研究;然而，TCDD介导的免疫毒性机制仍不清楚。缺乏机制的理解是由于，部分，难以证明TCDD对免疫功能的直接影响vitro.In这项研究中，我们已经研究了小鼠AhR的T细胞中的行为，使用分离的脾T淋巴细胞和T细胞克隆（10.5.17，F4，和F1.A.2）来自Ah-responsive小鼠品系。通过Western印迹法检测静息和活化脾淋巴细胞和T细胞克隆的全细胞提取物中AhR的存在。在T细胞克隆和脾细胞中观察到7-乙氧基试卤灵-O-脱乙基酶（EROD）活性增加;然而，TCDD诱导的EROD水平比Hepa细胞中诱导的水平低100倍。通过评估TCDD诱导的核转位和DNA结合来检查小鼠T细胞AhR的行为。通过亚细胞分级的静息和活化的T细胞的存在和不存在的TCDD的AhR的细胞内分布进行了研究。使用电泳迁移率变动分析测量DNA结合。AhR在所有检查的细胞类型中检测到，但AhR仅在活化的TCDD处理的T细胞中易位到细胞核。虽然来自TCDD处理的野生型hepa细胞的AhR特异性结合到DRE，但当使用从活化的T细胞获得的相同量的AhR时，未检测到结合。我们不能检测到T细胞核AhR复合物与共有反应元件的结合，结合观察到TCDD在体外难以再现体内免疫毒性效应，表明T细胞可能缺乏AhR与DRE结合所需的因子，或可能含有抑制AhR与DNA结合的抑制因子。基于这些数据，TCDD似乎通过间接机制影响T细胞功能。
Exposure of C57Bl/6 mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes suppression of both cell-mediated and humoral immunity. Studies with mice congenic at the Ah locus have demonstrated that this suppression is mediated by the aryl hydrocarbon receptor (AhR). The Ah receptor is a ligand-dependent transcription factor that has been well-studied in hepatocytes; however, the mechanism of TCDD-mediated immunotoxicity remains unknown. Lack of mechanistic understanding is due, in part, to difficulty demonstrating a direct effect of TCDD on immune functionin vitro.In this study, we have investigated the behavior of the murine AhR in T cells using isolated spleen T lymphocytes and T cell clones (10.5.17, F4, and F1.A.2) derived from Ah-responsive mouse strains. The presence of the AhR in whole cell extracts of resting and activated splenic lymphocytes and T cell clones was examined by Western blotting. Increased 7-ethoxyresorufin-o-deethylase (EROD) activity was observed in T cell clones and spleen cells; however, the level of EROD induction by TCDD was ∼100-fold less than the level induced in hepa cells. The behavior of the murine T cell AhR was examined by assessing TCDD-induced nuclear translocation and DNA binding. The intracellular distribution of the AhR was studied by subcellular fractionation of both resting and activated T cells in the presence and absence of TCDD. DNA binding was measured using an electrophoretic mobility shift assay. The AhR was detected in all cell types examined, but the AhR translocated to the nucleus only in activated, TCDD-treated T cells. While AhR derived from TCDD-treated wild-type hepa cells bound specifically to a DRE, no binding was detected when an identical amount of AhR obtained from activated T cells was used. Our inability to detect binding of the T cell nuclear AhR complex to a consensus response element, combined with the observation that it is difficult to reproduce thein vivoimmunotoxic effects of TCDDin vitro,suggests that T cells may lack a factor(s) required for AhR binding to a DRE, or may contain a suppressor factor which inhibits AhR binding to DNA. Based on these data, TCDD appears to affect T cell function via an indirect mechanism.