Transcriptional Regulation in Murine Regulatory T Cells and Suppressed CD4+ T Cells: Identification and Functional Analyses

小鼠调节性 T 细胞和抑制的 CD4 T 细胞的转录调控：鉴定和功能分析

• 批准号: 245118548
• 负责人: Professor Dr. Tobias Bopp
• 金额: --
• 依托单位: Institut für Immunologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/245118548?language=en
• 关键词: Transcriptional; Regulation; Murine; Regulatory; Cells

The maintenance of peripheral tolerance is largely based on CD4+FoxP3+ Thymus-derived regulatory T cells (Tregs). While on the one hand preventing the development of autoimmune and allergic diseases, Tregs contribute to cancer pathogenesis and progression. Therefore, the in vivo modulation of Treg-derived suppressive mechanisms is a worthwhile but challenging task. This can be achieved by either targeting the suppressive properties of Tregs directly or by rendering the responder cells, e.g. CD4+ T cells resistant to Treg-mediated suppression. However, the molecular principles of suppression still remain relatively obscure. Our analyses clearly revealed an important role of cAMP in Treg-mediated suppression. Coherently, we observed a strong induction and nuclear localization of the transcription factor Inducible cAMP Early Repressor (ICER) in suppressed CD4+ T cells in vitro as well as in vivo. CD4+ T cells from Icer-deficient mice revealed a strongly reduced susceptibility to Treg-mediated suppression in vitro. In addition, such mice are less susceptible in a B16F10 melanoma model indicating a reduced sensitivity of Icer-deficient T cells to Treg-mediated suppression.Since kinases strongly influence transcriptional regulation, we performed kinome analysis comparing conventional CD4+ T cells and Tregs. Casein kinase 2 (CK2) showed the highest activity in activated Tregs. Pharmacologic inhibition in vitro as well as genetic ablation of the beta subunit of CK2 specifically in Tregs demonstrated a crucial contribution of this kinase to the suppressive properties of Tregs. Hence, this project focuses on 1. the analysis of the molecular mechanisms steered by ICER in suppressed CD4+ T cells, 2. the downstream signaling events evoked by CK2 in Tregs contributing to their suppressive properties as well as 3. the interrelation of CK2 and cAMP-mediated induction of ICER.

外周耐受的维持主要基于CD4+FoxP3+胸腺衍生的调节性T细胞（TCFs）。虽然一方面防止自身免疫性和过敏性疾病的发展，但TdR有助于癌症发病机制和进展。因此，Treg衍生的抑制机制的体内调节是一项有价值但具有挑战性的任务。这可以通过直接靶向Treg的抑制特性或通过使应答细胞（例如CD4+ T细胞）对Treg介导的抑制具有抗性来实现。然而，抑制的分子原理仍然相对模糊。我们的分析清楚地揭示了cAMP在Treg介导的抑制中的重要作用。一致地，我们观察到一个强大的诱导和核定位的转录因子诱导型cAMP早期抑制因子（ICER）在抑制的CD4+ T细胞在体外以及在体内。来自Icer缺陷小鼠的CD4+ T细胞显示出对Treg介导的体外抑制的敏感性大大降低。此外，这样的小鼠在B16 F10黑色素瘤模型中不太敏感，表明Icer缺陷的T细胞对Treg介导的抑制的敏感性降低。酪蛋白激酶2（CK 2）在活化的TcR中显示最高活性。体外药理学抑制以及CK2 β亚基的基因消融，特别是在TcG中，证明了这种激酶对TcG抑制特性的重要贡献。因此，本项目的重点是1。ICER在抑制的CD 4 + T细胞中引导的分子机制分析，2.由CK2在TcR中诱发的下游信号传导事件有助于其抑制特性以及3. CK2与cAMP介导的ICER诱导的相互关系。