ROLE OF SH2D1A/SAP IN NKT CELL DEVELOPMENT AND FUNCTION

SH2D1A/SAP 在 NKT 细胞发育和功能中的作用

• 批准号: 6852322
• 负责人: KIM Erika NICHOLS
• 金额: $ 24.9万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-12-01 至 2006-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6852322
• 关键词: CD antigens; biological signal transduction; cell differentiation; cell population study; clinical research; cytogenetics; cytology; genetically modified animals; human subject; inborn immunodeficiency; laboratory mouse; leukocyte activation /transformation; natural killer cells; phenotype; protein structure function; receptor expression

DESCRIPTION (provided by applicant): The Src homology 2 domain-containing gene 1A (SH2D1A) encodes an adaptor molecule known as SAP that is defective in patients with X-linked lymphoproliferative disease (XLP), a disorder associated with abnormal antiviral and antitumor immunity. SAP is expressed in T cells and Natural Killer (NK) cells, where it regulates Thl and Th2 cytokine production, as well as cytotoxic function. To determine whether SAP controls the activity of NKT cells, a lymphocyte subset sharing features with T and NK cells, we examined SAP -/- mice and human XLP patients for the presence of this lineage. Remarkably, NKT cells were dramatically reduced or absent, suggesting that, in addition to its essential role in mature T and NK cells, SAP is required for NKT cell development. Consistent with the lack of NKT cells, SAP -/- mice failed to upregulate cytokines in response to a-galactosyl ceramide, a glycolipid antigen that specifically activates these cells. Based on these new findings, we hypothesize that SAP is a critical signaling molecule that is required for coordinating the biochemical pathways controlling NKT cell ontogeny. We also propose that the severe reduction in NKT cells, when combined with abnormally functioning T and NK cells, contributes to the pathogenesis of XLP. In this proposal, we aim to rigorously dissect the role of SAP during NKT cell development and mature NKT cell activation. To firmly establish whether SAP is required during human NKT cell differentiation, in Aim 1 we will use cell-based and molecular assays to evaluate NKT cell number in a larger spectrum of patients with XLP and related immunological defects. In Aim 2, we will study whether SAP is required for mature NKT cell function. After reconstituting NKT cell development in SAP -/- mice, WT and SAP -/-cells will be investigated using in vitro and in vivo assays. Structure-function analyses in Aim 3 will define how the domains within SAP mediate its participation in NKT cell signaling. These investigations will increase our understanding of NKT cell development and may enable the design of new treatments for XLP or other human diseases associated with quantitative or qualitative NKT cell defects, including immunodeficiency, autoimmunity and cancer.

描述（由申请人提供）：Src同源2结构域基因1A （SH2D1A）编码一种称为SAP的接头分子，该接头分子在x连锁淋巴细胞增生性疾病（XLP）患者中存在缺陷，XLP是一种与异常抗病毒和抗肿瘤免疫相关的疾病。SAP在T细胞和自然杀伤（NK）细胞中表达，在那里它调节Thl和Th2细胞因子的产生，以及细胞毒性功能。为了确定SAP是否控制NKT细胞的活性，我们检测了SAP -/-小鼠和人类XLP患者是否存在该谱系。NKT细胞是一种与T细胞和NK细胞共享特征的淋巴细胞亚群。值得注意的是，NKT细胞显著减少或缺失，这表明除了在成熟的T细胞和NK细胞中发挥重要作用外，SAP也是NKT细胞发育所必需的。与缺乏NKT细胞一致，SAP -/-小鼠在a-半乳糖神经酰胺（一种特异性激活这些细胞的糖脂抗原）的反应中未能上调细胞因子。基于这些新发现，我们假设SAP是协调控制NKT细胞个体发生的生化途径所必需的关键信号分子。我们还提出，NKT细胞的严重减少，当与功能异常的T和NK细胞结合时，有助于XLP的发病机制。在本提案中，我们的目标是严格剖析SAP在NKT细胞发育和成熟NKT细胞激活中的作用。为了确定在人类NKT细胞分化过程中是否需要SAP，在Aim 1中，我们将使用基于细胞和分子的方法来评估XLP和相关免疫缺陷患者的NKT细胞数量。在Aim 2中，我们将研究成熟的NKT细胞功能是否需要SAP。在SAP -/-小鼠中重建NKT细胞发育后，将使用体外和体内实验研究WT和SAP -/-细胞。Aim 3中的结构-功能分析将定义SAP中的结构域如何介导其参与NKT细胞信号传导。这些研究将增加我们对NKT细胞发育的理解，并可能为XLP或其他与定量或定性NKT细胞缺陷相关的人类疾病（包括免疫缺陷、自身免疫和癌症）设计新的治疗方法。