Nisbet-Brown E, Cheung R K, Lee J W, Gelfand E W
Nature. 1985;316(6028):545-7. doi: 10.1038/316545a0.
Calcium has been implicated as an intracellular messenger in the cellular response to various external stimuli. Exposure of lymphocytes to various mitogens and lectins results in rapid transmembrane calcium fluxes and increased cytoplasmic calcium concentrations ([Ca2+]i). It is not clear, however, whether the mechanisms by which these non-physiological stimuli activate cells are related to those involved in antigen-specific activation. We have now used antigen-specific T-cell clones to study changes in [Ca2+]i associated with specific activation and show here that these cells respond specifically in the presence of antigen and antigen-presenting cells (APC) with increased [Ca2+]i and that this increased [Ca2+]i shows the same genetic restrictions as are seen in the proliferation assay. The kinetics of the [Ca2+]i response to antigen indicate that antigen undergoes a time-dependent processing step as a prerequisite for recognition by T cells, as has been shown for T-cell proliferative responses, but that the [Ca2+]i response to processed antigen is extremely rapid. The close correlation between changes in [Ca2+]i and cell activation resulting in proliferation suggests that Ca2+ may act as an intracellular messenger in antigen-specific responses.
钙被认为是细胞对各种外部刺激作出反应时的一种细胞内信使。淋巴细胞暴露于各种促有丝分裂原和凝集素会导致快速的跨膜钙通量和细胞质钙浓度（[Ca2+]i）增加。然而，尚不清楚这些非生理性刺激激活细胞的机制是否与抗原特异性激活所涉及的机制相关。我们现在使用抗原特异性T细胞克隆来研究与特异性激活相关的[Ca2+]i变化，并在此表明这些细胞在抗原和抗原呈递细胞（APC）存在的情况下会特异性反应，[Ca2+]i增加，且这种增加的[Ca2+]i显示出与增殖试验中相同的遗传限制。[Ca2+]i对抗原反应的动力学表明，抗原经历一个时间依赖性的加工步骤，作为被T细胞识别的前提条件，正如T细胞增殖反应中所显示的那样，但[Ca2+]i对加工后抗原的反应极其迅速。[Ca2+]i变化与导致增殖的细胞激活之间的密切相关性表明，Ca2+可能作为抗原特异性反应中的一种细胞内信使。
