Identification and functional characterization of voltage-dependent calcium channels in T lymphocytes
Identification and functional characterization of voltage-dependent calcium channels in T lymphocytes
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DOI：
10.1074/jbc.m309268200
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发表时间：
2003-11-21
影响因子：
4.8
通讯作者：
Jefferies, WA
中科院分区：
文献类型：
--
作者：
Kotturi, MF;Carlow, DA;Jefferies, WA
在 T 淋巴细胞中，钙 (Ca2+) 通过位于质膜的 Ca2+ 通道持续流入对于 T 细胞的激活和增殖至关重要。先前的研究表明，电压依赖性 Ca2+ 通道 (VDCC) 在 T 淋巴细胞激活过程中的 Ca2+ 动员中发挥作用。然而，VDCC 在非兴奋性细胞中的作用仍然知之甚少。我们使用 RT-PCR 鉴定了编码 T 淋巴细胞中 L 型 Ca2+ 通道的成孔 α(1F) 亚基的转录本。它的身份通过 DNA 测序得到证实。为了进一步研究 Ca2+ 通过 VDCC 流入的贡献，我们评估了 1,4-二氢吡啶 L 型 Ca2(+) 通道激动剂 (+/-) Bay K 8644 和拮抗剂硝苯地平对人 Jurkat T 细胞白血病系、人外周血 T 淋巴细胞和小鼠脾细胞的影响。我们发现，用 (+/-) Bay K 8644 处理 T 淋巴细胞会增加细胞内 Ca2+ 并诱导磷酸细胞外调节激酶 1/2 (Erk1/2) 的激活，而硝苯地平则阻断 Ca2+ 内流、Erk1/2 的活性和活化 T 细胞的核因子 (NFAT)、白细胞介素 2 (IL-2) 的产生和 IL-2 受体的表达。硝苯地平还显着抑制体外混合淋巴细胞反应中的脾细胞增殖以及体内移植的雄性小鼠中雄性抗原(H-Y)特异性T细胞受体转基因CD8(+)T细胞的增殖。总而言之，这些新发现表明，L 型 Ca2+ 通道在介导体外和体内 T 淋巴细胞活化和增殖的 Ca2+ 流入途径中发挥着重要作用。
In T lymphocytes, sustained calcium (Ca2+) influx through Ca2+ channels localized in the plasma membrane is critical for T cell activation and proliferation. Previous studies indicated that voltage-dependent Ca2+ channels (VDCCs) play a role in Ca2+ mobilization during T lymphocyte activation. However, the role of VDCCs in otherwise nonexcitable cells is still poorly understood. We used RT-PCR to identify a transcript encoding the pore-forming alpha(1F)-subunit of an L-type Ca2+ channel in T lymphocytes. Its identity was confirmed by DNA sequencing. To further investigate the contribution of Ca2+ influx through VDCCs, we assessed the effects of the 1,4-dihydropyridine L-type Ca2(+) channel agonist, (+/-) Bay K 8644, and antagonist, nifedipine, on the human Jurkat T cell leukemia line, human peripheral blood T lymphocytes and mouse splenocytes. We found that treatment of T lymphocytes with (+/-) Bay K 8644 increased intracellular Ca2+ and induced the activation of phosphoextracellular-regulated kinase 1/2 (Erk1/2), whereas nifedipine blocked Ca2+ influx, the activity of Erk1/2 and nuclear factor of activated T cells ( NFAT), interleukin-2 (IL-2) production, and IL-2 receptor expression. Nifedipine also significantly suppressed splenocyte proliferation in an in vitro mixed lymphocyte reaction and the proliferation of male antigen (H-Y)-specific T cell receptor-transgenic CD8(+) T cells in transplanted male mice in vivo. Taken together these novel findings indicate that an L-type Ca2+ channel plays a significant role in the Ca2+ influx pathways mediating T lymphocyte activation and proliferation in vitro and in vivo.