Regulation of PMN activation by SLP-76, PRAM-1 and ADAP

SLP-76、PRAM-1 和 ADAP 对 PMN 激活的调节

• 批准号: 6808884
• 负责人: GARY A. KORETZKY
• 金额: $ 42.01万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-15 至 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6808884
• 关键词: antibody receptor; binding proteins; biological signal transduction; cell adhesion; cell line; cell migration; flow cytometry; free radical oxygen; gene expression; genetically modified animals; immunoglobulins; integrins; laboratory mouse; leukocyte activation /transformation; mutant; neutrophil; phosphoproteins; protein localization; protein protein interaction; protein structure function; proteins; western blottings

DESCRIPTION (provided by applicant): Polymorphonuclear cells (PMN) play integral roles in the immune response to invading microorganisms. Activated PMN, however, can damage host tissues due to the production of highly toxic proinflammatory mediators. To learn more about the mechanisms controlling PMN activation, we are studying how adaptor molecules coordinate the signaling pathways initiated by Fc receptors for immunoglobulin (Fc-gammaR) or beta2 integrins, receptors that regulate critical PMN functions. We have new information that the hematopoietic adaptor SLP-76 (SH2 domain-containing Leukocyte-specific Phosphoprotein of 76 kD) is inducibly tyrosine phosphorylated following Fc-gammaR and integrin ligation. Consistent with a possible role for this adaptor in the signaling pathways used by these receptors, SLP-76-/-PMN demonstrate reduced Fc-gammaR and absent integrin-mediated activation in vitro, including defective production of reactive oxygen species (ROS). From these and related observations, we hypothesize that SLP-76, and the SLP-76-associated adaptors PRAM-1 (PML-RARalpha target gene encoding an Adaptor Molecule-1) and ADAP (Adhesion and Degranulation-promoting Adaptor Protein) regulate PMN function by integrating Fc-gammaR and integrin-mediated signals. In this proposal, we will use complementary approaches to investigate this hypothesis and to rigorously dissect the spatial and biochemical requirements for these molecules during PMN activation. Structure-function analyses in Aim 1 will define the domains within SLP-76 that are required to mediate its cellular localization, interaction with associated proteins and PMN-specific functions. In Aim 2, we will use similar approaches to further investigate the roles of PRAM-1 and ADAP in PMN. In Aim 3, we will generate and characterize myeloid lineage-restricted gene-targeted mice to determine whether the loss of SLP-76, PRAM-1 and ADAP expression in vivo influences PMN activation in animal models of infection and autoimmunity. These investigations will increase out understanding of PMN function and may provide insights into the development of new treatments for human disorders associated with PMN activation, including immunodeficiency, infection and autoimmunity.

描述（由申请人提供）：多形核细胞（PMN）在针对入侵微生物的免疫反应中发挥着不可或缺的作用。然而，激活的中性粒细胞会由于产生剧毒促炎介质而损害宿主组织。为了了解更多关于控制 PMN 激活的机制，我们正在研究接头分子如何协调免疫球蛋白 Fc 受体 (Fc-gammaR) 或 β2 整联蛋白（调节关键 PMN 功能的受体）启动的信号传导途径。我们获得的新信息表明，造血接头 SLP-76（含有 SH2 结构域的 76 kD 白细胞特异性磷酸蛋白）在 Fc-gammaR 和整合素连接后可诱导酪氨酸磷酸化。与该接头在这些受体使用的信号通路中的可能作用一致，SLP-76-/-PMN 在体外表现出 Fc-gammaR 减少和缺乏整合素介导的激活，包括活性氧 (ROS) 的产生缺陷。根据这些和相关观察结果，我们假设 SLP-76 和 SLP-76 相关接头 PRAM-1（编码接头分子 1 的 PML-RARα 靶基因）和 ADAP（促进粘附和脱颗粒的接头蛋白）通过整合 Fc-gammaR 和整合素介导的信号来调节 PMN 功能。在本提案中，我们将使用补充方法来研究这一假设，并严格剖析中性粒细胞激活过程中这些分子的空间和生化要求。目标 1 中的结构功能分析将定义 SLP-76 内介导其细胞定位、与相关蛋白相互作用和 PMN 特异性功能所需的结构域。在目标 2 中，我们将使用类似的方法进一步研究 PRAM-1 和 ADAP 在 PMN 中的作用。在目标 3 中，我们将生成并表征骨髓谱系限制性基因靶向小鼠，以确定体内 SLP-76、PRAM-1 和 ADAP 表达的丧失是否会影响感染和自身免疫动物模型中的 PMN 激活。这些研究将加深对中性粒细胞功能的了解，并可能为开发与中性粒细胞激活相关的人类疾病（包括免疫缺陷、感染和自身免疫）的新疗法提供见解。