IL-1 activates the Na+/H+ antiport in a murine T cell.
IL-1 activates the Na+/H+ antiport in a murine T cell.
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DOI：
10.4049/jimmunol.143.12.4000
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发表时间：
1989-12
影响因子：
4.4
通讯作者：
Roberto Civitelli;Steven L. Teitelbaum;Keith A. Hruska;D. Lacey
中科院分区：
文献类型：
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作者：
Roberto Civitelli;Steven L. Teitelbaum;Keith A. Hruska;D. Lacey
生长因子暴露后的早期事件之一是细胞内pH升高，这是一个由Na+/H+反向通道介导的过程。我们研究了人rIL-1α(hrIL-1α)对小鼠T细胞系(MD10细胞)细胞内pH(Phi)和钙离子([Ca+]i)的影响，该细胞系仅对IL-1有反应。通过使用细胞内捕获的荧光染料(2(1)，7(1)-双-2-羧乙基)-5(和-6)羧基荧光素和Indo-1，我们监测了HrIL-1α对PHi和[Ca~(2+)]i的即时和早期响应。暴露于HrIL-1α(120 PM)会导致早期持续的细胞内碱化(增量pH=+0.09+/-0.03)，并在20分钟内进入平台期。较低浓度的单核细胞因子(12 PM和1.2 PM)对PHI有积极的影响，但在统计学上没有显著意义。这些影响与KD(49 Pm)预测的MD10 IL-1R饱和程度平行，通过MD10细胞的125I-HrIL-1α结合(Bmax=约1300)进行评估。然而，MD10 IL-1受体Kd和HrIL-1α浓度都超过了MD10增殖所需的HrIL-1αED50(50 FM)三个数量级。IL-1诱导的PHI升高既是钠依赖的，也是阿米洛利敏感的，表明Na+/H+逆向通道被激活。此外，PMA(100 NM)和IL-2(2 NM)使MD10细胞碱化，当PMA超过最大IL-1效应(增量pH=+0.13+/-0.04)时，PHI升高。此外，尽管PMA使先前暴露于HrIL-1α的细胞碱化，但单核细胞因子并不改变PMA处理的MD10细胞的PHI。重要的是，由HrIL-1α或PMA诱导的细胞内碱化可被星形孢子素(1muIm)抑制。最后，HrIL-1α不会以急性或持续方式改变MD10[Ca~(2+)]i。这些结果表明，IL-1激活T细胞Na+/H+逆向转运蛋白的机制与细胞内[Ca~(2+)]i的变化无关，但可能与蛋白激酶C的激活有关。
One of the early events following growth factor exposure is elevation of intracellular pH, a process mediated by the Na+/H+ antiport. We studied the effects of human rIL-1 alpha (HrIL-1 alpha) on intracellular pH (pHi) and calcium ([Ca2+]i) in a murine T cell line (MD10 cells), which proliferates in response to IL-1 alone. By using the intracellularly trapped fluorescent dyes (2(1),7(1)-bis-2-carboxyethyl)-5(and -6) carboxyfluorescein) and indo-1, we monitored immediate to early changes of pHi and [Ca2+]i in response to HrIL-1 alpha. Exposure to HrIL-1 alpha (120 pM) leads to an early, sustained intracellular alkalinization (delta pH = + 0.09 +/- 0.03) that plateaus within 20 min. Lower concentrations of the monokine (12 pM, 1.2 pM) have a positive but not statistically significant effect on pHi. These effects parallel the degree of MD10 IL-1R saturation predicted by the KD (49 pM) as assessed by 125I-HrIL-1 alpha binding by MD10 cells (Bmax = approximately 1300). Both the MD10 IL-1 receptor KD and the HrIL-1 alpha concentration required to induce early measurable alkaline pH shifts, however, exceed by three orders of magnitude the HrIL-1 alpha ED50 (50 fM) required for MD10 proliferation. The IL-1-induced rise in pHi is both sodium dependent and amiloride sensitive, indicative of activation of the Na+/H+ antiport. Additionally, PMA (100 nM) and IL-2 (2 nM) alkalinize MD10 cells, with the rise in pHi as a result of PMA exceeding the maximal IL-1 effect (delta pH = + 0.13 +/- 0.04). Furthermore, although PMA alkalinizes cells previously exposed to HrIL-1 alpha, the monokine does not alter the pHi of PMA-treated MD10 cells. Importantly, intracellular alkalinization induced by either HrIL-1 alpha or PMA is inhibited by staurosporine (1 mu iM). Finally, HrIL-1 alpha does not change MD10 [Ca2+]i, in either an acute or sustained fashion. These results indicate that IL-1 activates the Na+/H+ antiport in T cells by a mechanism that is unrelated to changes in [Ca2+]i but may involve protein kinase C activation.