Novel Mucosal Regulatory DC4+ T Cells: Interface Between Th17 and Treg

本项目中提议的研究的基础反映了最初的和 我们实验室长期观察到，调节性T细胞在与正常T细胞相互作用后被激活 肠上皮细胞。这些研究还记录了CD8 Treg激活的缺陷，当上皮细胞 用来自IBD患者的细胞来激活T细胞。在确定剧目的过程中 在上一个授予周期中，调节性T细胞存在于正常和炎症的肠道中，我们发现了一个 CD固有层中新的CD4FoxP3/IL17双阳性细胞群，而非UC和正常人 病人。这些细胞具有Th17细胞的表型特征，分泌IL17、IL22。IL21而 高表达CCR6、CD161和RORyt。然而，与传统的Th17(细胞和类似于 Foxp3Tregs，它们表达高水平的CD101和低水平的CD127，表现出类似的TCR谱系 (BV使用)，并在体外共培养系统中具有功能抑制作用。产生Foxp3 IL-17的细胞是 印迹用于肠道归巢，CCR6、CD103和整合素a4b7的高水平表达表明。 这些细胞能分泌IFNy，但不能分泌IL10或TGFb。因此，它们代表了一种新的细胞群体，可以 为Tregs与Th17细胞的谱系承诺提供有用的见解。我们认为这些细胞位于 在Treg和Th17细胞之间的十字路口，进一步致力于任一血统的结果是 微环境线索存在于组织中。目前的提案试图描述这些细胞的特征，并 定义激活过程中涉及的因素。最重要的是，我们的目标是确定微环境线索 这允许这些细胞致力于Th17(更有可能在CD中)，而不是调节谱系。我们将：1) 明确CD4FoxP3/IL17双阳性细胞的功能和表型特性 Cd；2)定义导致调节血统的转录程序的微环境线索 这些细胞的承诺。与熊博士在项目3(IRF8)中合作，评估互动 在FoxP3和RORyt之间，并确定允许对这两种转录进行负调控的因素 各种因素。3)在回肠炎/结肠炎小鼠模型或小鼠感染模型中确定这些细胞的对应物 与Lira博士和Blander博士合作，建立他们在体内生成所需的条件。

The basis of the studies proposed in this project reflect the findings emanating from the initial and longstanding observations in our lab that regulatory T cells are activated following interactions with normal intestinal epithelial cells. These studies also documented defects in CD8+ Treg activation when epithelia cells derived from IBD patients were used to activate T cells. During the course of defining the repertoire of regulatory T cells present in normal and inflamed intestine during the last granting cycle, we identified a novel population of CD4+ FoxP3/IL17 double positive cells in the lamina propria of CD but not UC or normal patients. These cells share phenotypic characteristics of Th17 cells with secretion of IL17, IL22. IL21 while expressing high levels of CCR6, CD161, and RORyt. However, unlike conventional Th17 (cells and similar to FoxP3+ Tregs, they express high levels of CD101 and low levels of CD127, exhibit a similar TcR repertoire (BV usage) and are functionally suppressive in in vitro co-culture systems. FoxP3+IL-17 producing cells are imprinted for gut homing, as indicated by high levels of CCR6, CD103 and the integrin a4B7 expression. These cells secrete IFNy but not IL10 or TGFB. Thus they represent a novel cell population that could provide useful insights into lineage commitment of Tregs versus Th17 cells. We propose that these cells sit at the crossroads between Treg and Th17 cells and that further commitment to either lineage results from microenvironmental cues present in the tissues. The current proposal seeks to characterize these cells and define factors involved in their activation. Most importantly we aim to detemiine the microenvironmental cues that allow these cell to commit to a Th17 (more likely in CD) rather than a regulatory lineage. We will: 1) Define the functional and phenotypic properties of the CD4+ FoxP3/IL17 double positive cells derived from CD; 2) Define the microenvironmental cues leading to a transcriptional program that regulates lineage commitment of these cells. In collaboration with Dr. Xiong in Project 3 (IRF8), assess the interactions between FoxP3 and RORyt and determine factors that allow for negative regulation of both transcription factors. 3) Identify counterparts of these cells in murine models of ileitis/colitis or murine infection models in collaboration with Drs. Lira and Blander to establish the conditions required for their generation in vivo.