Baldwin Troy A, Hogquist Kristin A, Jameson Stephen C
Center for Immunology, Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA.
J Immunol. 2004 Dec 1;173(11):6515-20. doi: 10.4049/jimmunol.173.11.6515.
During late stages of thymic development, T cells must chose between different fates, dictated by their TCR specificity. Typically, this is thought of as a choice between three alternatives (being positive selection for useful T cells vs negative selection or neglect for harmful or useless T cells). However, there is growing evidence for a fourth alternative, in which T cells are positively selected by agonist ligands, which would normally be expected to induce T cell deletion. In this review, we will discuss where and when agonist selection is induced and whether this should be considered as a novel form of thymic selection or as an alternative differentiation state for Ag-exposed T cells.
在胸腺发育的后期，T细胞必须根据其TCR特异性在不同命运之间做出选择。通常，这被认为是三种选择之间的抉择（对有用的T细胞进行阳性选择，而对有害或无用的T细胞进行阴性选择或忽视）。然而，越来越多的证据表明存在第四种选择，即T细胞被激动剂配体进行阳性选择，而激动剂配体通常会诱导T细胞删除。在这篇综述中，我们将讨论激动剂选择在何处以及何时被诱导，以及这是否应被视为一种新的胸腺选择形式，或者是抗原暴露T细胞的一种替代分化状态。
