Nuffield Department of Clinical Medicine and Medical Research Council Human Immunology Unit, The Weatherall Institute of Molecular Medicine, University of Oxford, Oxford Radcliffe Hospital, Oxford OX3 9DS, UK.
Trends Immunol. 2011 Jan;32(1):1-5. doi: 10.1016/j.it.2010.11.003. Epub 2010 Dec 27.
Exactly how ligand binding 'triggers' T cell receptor (TCR) phosphorylation is unclear. It has been proposed that ligand engagement by the TCR somehow activates the Src kinase Lck, which in turn phosphorylates the receptor. Recent data, however, suggest instead that a significant fraction of the Lck in resting T cells is already activated and that the proportion of active Lck does not change during the early stages of T cell activation. We argue that, caveats notwithstanding, these new observations offer support for the 'kinetic-segregation' model of TCR triggering, which involves spatial reorganization of signalling proteins upon ligand binding and requires a fraction of Lck to be active in resting T cells.
配体结合如何“触发” T 细胞受体（TCR）磷酸化尚不清楚。有人提出，TCR 与配体的结合以某种方式激活Src 激酶 Lck，后者反过来磷酸化受体。然而，最近的数据表明，静止 T 细胞中已有相当一部分 Lck 已经被激活，并且在 T 细胞激活的早期阶段，活性 Lck 的比例并没有改变。我们认为，尽管存在警告，但这些新的观察结果为 TCR 触发的“动力学分离”模型提供了支持，该模型涉及配体结合时信号蛋白的空间重排，并且需要静止 T 细胞中一部分 Lck 处于活性状态。
