Voltage-gated potassium channels are required for human T lymphocyte activation.
Voltage-gated potassium channels are required for human T lymphocyte activation.
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DOI：
10.1084/jem.160.2.369
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发表时间：
1984-08-01
期刊：
影响因子：
--
通讯作者：
Gupta S
中科院分区：
文献类型：
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作者：
Chandy KG;DeCoursey TE;Cahalan MD;McLaughlin C;Gupta S
钙通道阻滞剂维拉帕米和地尔硫卓在阻断T淋巴细胞K通道电流的浓度下抑制植物血凝素（PHA）诱导的有丝分裂。K通道阻滞剂也以剂量依赖的方式抑制同种异体混合淋巴细胞反应，其效价序列与阻断K电流相同。K通道阻滞剂只有在加入PHA后的前20-30小时内才能抑制PHA刺激的有丝分裂，而不是在此之后，这表明在此期间需要功能性的K通道。我们研究了K通道阻滞剂对蛋白质合成的各个方面的影响，原因有两个：首先，蛋白质合成似乎是导致DNA合成的事件所必需的，其次，蛋白质合成速率的增加开始于添加PHA后的第一个24-48小时。K通道阻滞剂以剂量依赖的方式将pha诱导的总蛋白合成降低到未刺激T淋巴细胞的水平，其效价序列与阻断K电流和抑制[3H]胸苷结合的效价序列相同。二维凝胶电泳显示，尽管K通道阻滞剂将大多数蛋白质的合成降低到未刺激T细胞的水平，但与静息细胞相比，一些蛋白质的合成速度继续提高。在未受刺激的T淋巴细胞中，通过二维凝胶电泳检测到两种蛋白质S和T，在pha处理的T淋巴细胞中，两种蛋白质的强度似乎降低了，而其余蛋白质的合成则增加了。在抑制蛋白合成的浓度下，4-氨基吡啶（4-AP）可以阻止pha诱导的蛋白S和T的明显减少。这些蛋白可能在维持T淋巴细胞处于静息状态中发挥作用，并且可能与翻译抑制因子有关，这些因子在静止T淋巴细胞中比在pha激活的T细胞中具有更高的特异性活性。在T淋巴细胞活化过程中，IL-2受体（Tac）的表达不受K通道阻滞剂的影响，而白细胞介素2 （IL-2）的产生在未受刺激的T淋巴细胞中降低到原来的水平。外源性IL-2通过低浓度（而不是高浓度）的4-AP部分缓解了对有丝分裂发生的抑制。这些实验阐明了K通道在T淋巴细胞活化中的作用，并表明功能性K通道是蛋白质合成或导致蛋白质合成的事件所必需的。
The calcium channel blockers, verapamil and diltiazem, inhibit phytohemagglutinin (PHA)-induced mitogenesis at concentrations that block the T lymphocyte K channel currents. K channel blockers also inhibit the allogeneic mixed lymphocyte response in a dose-dependent manner with the same potency sequence as for block of K currents. K channel blockers inhibit PHA-stimulated mitogenesis only if added during the first 20-30 h after PHA addition, but not later, indicating a requirement for functional K channels during this period. We investigated the effect of K channel blockers on various aspects of protein synthesis for two reasons: first, protein synthesis appears to be necessary for the events leading to DNA synthesis, and second, the increase in the protein synthetic rate commences during the first 24-48 h after PHA addition. PHA-induced total protein synthesis was reduced to the level in unstimulated T lymphocytes by K channel blockers in a dose-dependent manner with the same potency sequence as for the block of K currents and inhibition of [3H]thymidine incorporation. Two- dimensional gel electrophoresis demonstrated that although the synthesis of the majority of proteins was reduced by K channel blockers to the level in unstimulated T cells, some proteins continued to be synthesized at an enhanced rate compared with resting cells. Two proteins, S and T, detected by two-dimensional gel electrophoresis in unstimulated T lymphocytes, appeared to be reduced in intensity in gels of PHA-treated T lymphocytes, in contrast to the increased synthesis of the remaining proteins. 4-Aminopyridine (4-AP), at concentrations that inhibit protein synthesis, prevented the apparent PHA-induced reduction of proteins S and T. These proteins may play a role in maintaining the T lymphocyte in a resting state and may be related to the translation inhibitory factors reported to be present at a higher specific activity in quiescent T lymphocytes than in PHA-activated T cells. The expression of the IL-2 receptor (Tac) during T lymphocyte activation was not altered by K channel blockers, whereas the production of interleukin 2 (IL-2) was reduced to the level in unstimulated T lymphocytes. Exogenous IL-2 partially relieved the inhibition of mitogenesis by low, but not by high, concentrations of 4-AP. These experiments clarify the role of K channels in T lymphocyte activation and suggest that functional K channels are required either for protein synthesis or for events leading to protein synthesis.