Molecular and genomic control of innate γδ T cell development

项目摘要/摘要 γδNKT(也称为NKγδT或Vδ6.3T)谱系代表一种先天类型的γδT细胞，它产生于 新生儿的胸腺，随后在胸腺、脾和其他组织中维持终生 肝脏。这些细胞与αβ血统的iNKT细胞密切相关，后者表达半不变的αβTCR，以及 它们共同构成了先天T淋巴细胞的主要群体。先天类T细胞的主要功能 淋巴细胞是调节包括传统T细胞在内的其他免疫细胞的发育和功能 淋巴细胞。γδNKT细胞使用刻板的Vγ1.1Vδ6.3TCR；然而，他们的配体(S)仍然未知。这个 胸腺中DNANKT细胞的生成受γδ结合蛋白E盒家族活性的严格控制 (E蛋白)，它们在T细胞发育中发挥着深远的作用。E蛋白的活性受ID蛋白的抑制。 ID家族蛋白ID3是由TCR信号强度与TCR信号强度成比例地诱导的，是ID3-E 蛋白质平衡对γδ神经干细胞的生成起着至关重要的调节作用。本计划项目完成的工作 已经揭示了TCR信号协调E蛋白与一系列 γδT谱系规范、分化和扩展过程中的增强剂。然而，关键E的身份 控制个体γδT亚系发育的蛋白质靶点仍然是知识的主要缺口。 我们与项目1一起确定了调控γδNKT发展的两个关键E蛋白靶点 细胞：编码定型的Vγ1.1Vδ6.3TCR的基因组元件和一个发挥作用的转录因子 在执行TCR发起的差异化计划中发挥关键作用。我们现在建议澄清 E蛋白调节γδNKT发育并限制其进入新生儿生活的机制。我们将通过以下方式做到这一点 目标有以下几点。在目标1中，我们将研究E-蛋白在调控重组事件中的功能 负责生成Vδ6.3TCR链。在目标2中，我们将检查刻板印象的独特性质 Vγ1.1Vδ6.3TCR及E蛋白如何协调Vγ1.1Vδ6.3TCR引发的基因表达变化 信号。目前的建议是建立在从方案项目中得出的主要观察结果之上的。建议数 实验将继续汲取TCR信号领域的补充专业知识(项目1)，MICE 遗传学(项目2)，小鼠和人类T细胞发育的体外模拟(项目3)，基因组学和 分子成像技术(项目4)。我们的具体目标不仅将使我们更好地理解 γδNKT的发展机制，但也将提供对一般机制的独特见解，通过 哪些E蛋白控制着细胞的命运。

PROJECT SUMMARY/ABSTRACT The γδNKT (also known as NKγδT or Vδ6.3 T) lineage represents an innate type of γδT cells that is generated in the neonatal thymus and subsequently maintained throughout life in tissues such as the thymus, spleen, and liver. These cells are closely related to αβ lineage iNKT cells, which express a semi-invariant αβTCR, and together they constitute the main populations of innate-like T lymphocytes. A major function of innate-like T lymphocytes is to modulate the development and function of other immune cells including conventional T lymphocytes. γδNKT cells use a stereotyped Vγ1.1Vδ6.3 TCR; however, their ligand(s) remains unknown. The generation of γδNKT cells in the thymus is tightly controlled by the activity of E box family of DNA-binding proteins (E proteins), which play profound roles in T cell development. The activity of E proteins is inhibited by Id proteins. The Id family protein, Id3, is induced by TCR signaling in proportion to TCR signal strength and it is the Id3-E protein balance that critically regulates the generation of γδNKT cells. Work completed by this Program Project has revealed that TCR signals orchestrate genome-wide remodeling of E protein binding to a constellation of enhancers during γδT lineage specification, differentiation, and expansion. However, the identity of the critical E protein targets that control the development of individual γδ T sublineages remains a major gap in knowledge. We, together with Project 1, have identified two critical E protein targets that regulate the development of γδNKT cells: the genomic elements encoding the stereotyped Vγ1.1Vδ6.3 TCR and a transcription factor that plays a crucial role in executing the differentiation program initiated by the TCR. We now propose to elucidate the mechanism by which E-proteins regulate γδNKT development and restrict it to neonatal life. We will do so through the following aims. In aim 1, we will investigate E-protein function in regulating the recombination events responsible for generation of the Vδ6.3 TCR chain. In aim 2, we will examine the unique nature of the stereotyped Vγ1.1Vδ6.3 TCR and how E-proteins coordinate the changes in gene expression triggered by Vγ1.1Vδ6.3 TCR signals. The current proposal is built upon key observations derived from the Program Project. The proposed experiments will continue to draw the complementary expertise in the areas of TCR signaling (Project 1), mouse genetics (Project 2), in vitro modeling of mouse and human T cell development (Project 3), and genomics and molecular imaging technologies (Project 4). Our specific aims will not only lead to a better understanding of the mechanism of γδNKT development but will also provide unique insight into the general mechanisms through which E proteins control cell fate.