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）：含Src同源2结构域的基因1A（SH 2D 1A）编码称为SAP的衔接分子，该衔接分子在X连锁淋巴增生性疾病（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，其中它调节Thl和Th 2细胞因子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，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，我们检查了SAP -/-小鼠和人XLP患者是否存在这种谱系。值得注意的是，NKT细胞显著减少或不存在，这表明除了其在成熟T和NK细胞中的重要作用外，SAP是NKT细胞发育所必需的。与缺乏NKT细胞一致，SAP -/-小鼠未能上调细胞因子以响应α-半乳糖基神经酰胺，一种特异性激活这些细胞的糖脂抗原。基于这些新的发现，我们假设SAP是一个关键的信号分子，需要协调控制NKT细胞个体发育的生化途径。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。在这项提案中，我们的目标是严格剖析SAP在NKT细胞发育和成熟NKT细胞活化过程中的作用。为了确定SAP在人NKT细胞分化过程中是否是必需的，在目标1中，我们将使用基于细胞的和分子测定来评估更大范围的XLP和相关免疫缺陷患者中的NKT细胞数量。在目标2中，我们将研究SAP是否是成熟NKT细胞功能所必需的。在SAP -/-小鼠中重建NKT细胞发育后，将使用体外和体内试验研究WT和SAP -/-细胞。目标3中的结构-功能分析将定义SAP内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，并可能设计新的治疗方法，用于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。