Endrizzi Bart T, Jameson Stephen C
Center for Immunology and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, MN 55455, USA.
Int Immunol. 2003 Nov;15(11):1341-8. doi: 10.1093/intimm/dxg133.
Kruppel-like Factor 2 [KLF2, also called lung Kruppel-like factor (LKLF)] is a transcription factor shown to be necessary for the maintenance of naive T cells. KLF2 is expressed in both naive and memory cells, and is proposed to promote quiescence in these populations. During T cell stimulation, both KLF2 protein and mRNA are down-regulated, and loss of KLF2 appears to be critical for full T cell activation. It is unclear, however, how KLF2 expression is maintained in naive T cells. Recently it was proposed that IL-7, which is known to promote KLF2 re-expression in antigen-stimulated T cells, may also induce KLF2 expression in naive T cells. Here we address this issue by comparing the impact of IL-7 on KLF2 expression in naive and activated T cells. Use of bcl-2 transgenic T cells allowed us to uncouple the requirements for IL-7 in preserving naive T cell survival from its role in maintaining KLF2 expression. Our data demonstrates that IL-7 signals are not required for KLF2 maintenance in naive T cells, suggesting that this cytokine has distinct effects on KLF2 expression in naive versus activated T cells.
克鲁ppel样因子2 [KLF2，也称为肺克鲁ppel样因子（LKLF）]是一种转录因子，已证明对维持初始T细胞是必需的。KLF2在初始细胞和记忆细胞中均有表达，并被认为可促进这些细胞群体的静止状态。在T细胞刺激过程中，KLF2蛋白和mRNA均下调，而KLF2的缺失似乎对T细胞的完全激活至关重要。然而，目前尚不清楚KLF2在初始T细胞中是如何维持表达的。最近有人提出，已知能促进抗原刺激的T细胞中KLF2重新表达的白细胞介素-7（IL-7），也可能诱导初始T细胞中KLF2的表达。在这里，我们通过比较IL-7对初始T细胞和活化T细胞中KLF2表达的影响来解决这个问题。使用bcl-2转基因T细胞使我们能够将IL-7在维持初始T细胞存活方面的需求与其在维持KLF2表达方面的作用区分开来。我们的数据表明，初始T细胞中维持KLF2不需要IL-7信号，这表明这种细胞因子对初始T细胞和活化T细胞中KLF2的表达有不同的影响。
