Regulation of T cell Differentiation

T 细胞分化的调节

• 批准号: 7592251
• 负责人: WARREN STROBER
• 金额: $ 118.33万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7592251
• 关键词: Area; Cell Differentiation process; Cell Nucleus; Cell physiology; Cells; Disease; Goals; Green Fluorescent Proteins; IL2RA gene; Immunosuppression; In Vitro; Inflammatory; Inflammatory Bowel Diseases; Interleukin-17; Interleukin-6; Knock-in Mouse; Knowledge; Laboratories; Ligands; Link; Luciferases; Mediating; Membrane; Regulation; Reporter; Reporting; Signal Pathway; Signal Transduction; Sorting - Cell Movement; System; T-Lymphocyte; Therapeutic Uses; Therapeutic immunosuppression; Transforming Growth Factor beta; inhibiting antibody; notch protein; promoter

Project 1:Previous studies have shown that the Notch1 and TGF-β signaling pathways are mutually re-enforcing. Given recent evident that regulatory T cell (Treg) effector function is mediated by TGF-β signaling, we investigated if Notch1 signaling also participated in Treg effector function. Initial studies showed that Notch1 ligands, particularly Jagged1, is present on Tregs and that, indeed, blockade of Notch1 signaling with a anti-Jagged1 or a blocking anti-Notch1 antibody inhibits Treg suppressor function in vitro. We then showed that a signaling component generated by Notch1 activation (NICD) physically interacts with a signaling component generated by TGF-β signaling (pSmad3). Furthermore, this interaction has functional downstream effects since over-expression of NICD facilitates pSmad3 translocation to the nucleus and enhances pSmad3 transcriptional activity of a Smad sensitive promoter linked to a luciferase reporter. Finally, we showed that blockade of TGF-β signaling and Notch signaling did not have additive inhibitory effects on Treg suppressor function. These results are consistent with the conclusion that Notch1 signaling enhances and facilitates TGF-β-mediated effector function of Tregs. Project 2: Recent studies have shown that TGF-β together with IL-6 induce the differentiation of IL-17-producing T cells (Th17) T cells. We therefore examined if CD4+CD25+Foxp3+ regulatory T cells (Tregs), i.e., cells previously shown to produce TGF-β, serve as Th17 inducers. We found that upon activation purified CD25+ T cells (or sorted GFP+ T cells obtained from Foxp3-GFP knock-in mice) produce high amount of soluble TGF-β and when cultured with CD4+CD25-Foxp3- T cells in the presence of IL-6 induce the latter to differentiate into Th17 cells. Perhaps more importantly, upon activation, CD4+CD25+Foxp3+(GFP+) T cells themselves differentiate into Th17 cells in the presence of IL-6 (and in the absence of exogenous TGF-β). These results indicate that CD4+CD25+Foxp3+ regulatory T cells can function as inducers of Th17 cells and can differentiate into Th17 cells. They thus have important implications to our understanding of regulatory T cell function and their possible therapeutic use.

项目1：之前的研究表明Notch1和TGF-β信号通路是相互增强的。 鉴于最近有证据表明调节性 T 细胞 (Treg) 效应器功能是由 TGF-β 信号传导介导的，我们研究了 Notch1 信号传导是否也参与了 Treg 效应器功能。 初步研究表明，Notch1 配体，特别是 Jagged1，存在于 Tregs 上，并且事实上，用抗 Jagged1 或阻断性抗 Notch1 抗体阻断 Notch1 信号传导会在体外抑制 Treg 抑制功能。 然后我们表明，Notch1 激活 (NICD) 产生的信号传导成分与 TGF-β 信号传导 (pSmad3) 产生的信号传导成分发生物理相互作用。此外，这种相互作用具有功能性下游效应，因为 NICD 的过度表达促进 pSmad3 易位到细胞核，并增强与荧光素酶报告基因连接的 Smad 敏感启动子的 pSmad3 转录活性。 最后，我们证明阻断 TGF-β 信号和 Notch 信号不会对 Treg 抑制功能产生附加抑制作用。 这些结果与 Notch1 信号增强和促进 TGF-β 介导的 Tregs 效应功能的结论一致。 项目2：最近的研究表明，TGF-β与IL-6一起诱导产生IL-17的T细胞（Th17）T细胞的分化。因此，我们检查了 CD4+CD25+Foxp3+ 调节性 T 细胞 (Treg)（即先前显示可产生 TGF-β 的细胞）是否可充当 Th17 诱导剂。 我们发现，纯化的 CD25+ T 细胞（或从 Foxp3-GFP 敲入小鼠获得的分选的 GFP+ T 细胞）激活后会产生大量可溶性 TGF-β，并且当与 CD4+CD25-Foxp3- T 细胞在 IL-6 存在的情况下培养时，会诱导后者分化为 Th17 细胞。也许更重要的是，激活后，CD4+CD25+Foxp3+(GFP+) T 细胞本身在 IL-6 存在（且不存在外源 TGF-β）的情况下分化为 Th17 细胞。这些结果表明CD4+CD25+Foxp3+调节性T细胞可以作为Th17细胞的诱导剂，并且可以分化为Th17细胞。因此，它们对我们理解调节性 T 细胞功能及其可能的治疗用途具有重要意义。