Regulation of Natural Killer T cell maturation, homeostasis and activation

项目概要/摘要： 自然杀伤T（NKT）细胞是免疫系统的先天性细胞，能够迅速激活和产生 细胞因子。NKT细胞已被证明在细菌、病毒和真菌感染期间应答，以及 在自身免疫性疾病中起作用;在镰状细胞病和哮喘中对肺组织造成损害;以及 检测和消除恶性细胞。虽然特定的转录因子和信号分子 已被证明对NKT细胞的早期发育是重要的，它们所需的许多因子 外周中的成熟、维持和激活仍然是未知的。我最近展示了 转录因子HEB是NKT细胞发育所必需的，也表明转录调节因子HEB是NKT细胞发育所必需的。 Id 2控制NKT细胞在组织如肺和肝中的存活。这一建议将阐明E的作用 蛋白和Id蛋白在这种重要细胞类型的分化中的作用。我将探索NKT细胞如何对 急性与慢性感染以及与它们的激活与无反应性沉默相关的因素。我会 研究感染期间NKT细胞活化如何影响其他适应性免疫细胞，即CD 8 + T细胞。到 为此，我提出以下目标。目的1：研究Id 2和Id 3在NKT细胞凋亡中的作用。 分化和这些细胞的稳态和活化。我目前的数据显示 调节因子Id 2-和Id 3-在NKT细胞分化过程中和在成熟NKT细胞中不稳定表达， 外周组织我建议，使用最近生成的Id 2和Id 3的报告细胞系，以及Id 2和Id 3- 缺陷株，以检查这些转录调节因子如何影响NKT细胞成熟和活化。目标二： 了解NKT细胞对急性和慢性感染的反应。NKT细胞产生大量的 细胞因子，以及表现出细胞毒性功能。这种激活爆发之后是无反应性的 细胞经历凋亡或保持抗增殖的阶段。目前尚不清楚这种无反应性是否 在慢性感染期间，NKT细胞中是否存在持续的细胞分裂期，或者NKT细胞是否由于持续的细胞分裂而保持活性。 抗原刺激使用LCMV作为急性和慢性感染的模型，我将检查NKT细胞的反应 持续的抗原刺激。此外，使用微阵列基因表达分析，我建议检查 NKT细胞在感染过程中通过无反应期时发生的分子变化。 这些研究的结果将有助于了解胸腺中NKT细胞的发育， 外周组织以及在急性和慢性感染中激活它们所需的因子。目标3：定义 NKT细胞如何影响活化后CD 8 + T细胞效应子和记忆形成。当NKT细胞产生 许多炎性细胞因子被激活时，这如何影响CD 8+效应和记忆T细胞的形成， 在感染过程中对炎症环境非常敏感，这是完全未知的。使用 NKT细胞缺陷小鼠和T细胞受体转基因小鼠，我将检测效应和记忆CD 8 + T细胞 在感染过程中NKT细胞不存在的情况下的形成和功能。这些研究将有助于定义 NKT细胞在急性感染中的重要性，并将评估这些细胞如何影响免疫记忆， 免疫系统的重要组成部分，需要保护免受随后的感染。这些研究将 对未来的疫苗设计和效力至关重要。

Project Summary/Abstract: Natural Killer T (NKT) cells are innate-like cells of the immune system, capable of swift activation and production of cytokines. NKT cells have been shown to respond during bacterial, viral and fungal infections, as well as playing roles in autoimmune disease; causing damage to lung tissue in sickle cell disease and in asthma; and in the detection and elimination of malignant cells. While specific transcription factors and signaling molecules have been shown to be important for early stage development of NKT cells, many of the factors required for their maturation, maintenance and activation in the periphery remain unknown. I recently showed that the transcription factor HEB is essential for NKT cell development and also showed that the transcriptional regulator Id2 controls survival of NKT cells in tissues such as lung and liver. This proposal will illuminate the role of E proteins and the Id proteins in differentiation of this important cell type. I will explore how NKT cells respond to acute versus chronic infection and the factors associated with their activation versus anergic silencing. I will examine how NKT cell activation during infection affects other adaptive immune cells, namely CD8+ T cells. To this end I propose the following aims. Aim 1: Examine the role of both Id2 and Id3 during NKT cell differentiation and in the homeostasis and activation of these cells. My current data suggest the transcriptional regulators Id2- and Id3- are reciprocally expressed during NKT cell differentiation and in mature NKT cells in peripheral tissues. I propose, using recently generated reporter lines for Id2 and Id3, as well as Id2 and Id3- deficient lines, to examine how these transcriptional regulators impact NKT cell maturation and activation. Aim 2: Understanding NKT cell response to acute and chronic infection. NKT cells produce prodigious quantities of cytokines upon activation, as well as exhibiting cytotoxic function. This activation burst is followed by an anergic phase in which cells undergo apoptosis or remain resistant to proliferation. It is not known whether this anergic phase occurs in NKT cells during chronic infection or indeed whether NKT cells retain activity due to continual antigen stimulation. Using LCMV as a model of acute and chronic infection, I will examine the NKT cell response to persistent antigen stimulation. Furthermore, using microarray gene-expression analysis, I propose to examine the molecular changes that occur in NKT cells as they transition through the unresponsive phase during infection. The results from these studies will be useful in understanding development of NKT cells in the thymus and peripheral tissues as well as the factors required for their activation in acute and chronic infection. Aim 3: Define how NKT cells affect CD8+ T cell effector and memory formation upon activation. While NKT cells produce numerous inflammatory cytokines when activated, how this affects CD8+ effector and memory T cell formation, which are exquisitely sensitive to the inflammatory environment during infection, is completely unknown. Using NKT cell-deficient mice and T cell receptor-transgenic mice, I will examine effector and memory CD8+ T cell formation and function in the absence of NKT cells during infection. These studies will help to define the importance of NKT cells in acute infection and will assess how these cells influence immunological memory, an essential component of the immune system, required for protection from subsequent infection. These studies will be important for future vaccine design and efficacy.