Biology of the Human Platelet Fc(gamma) Receptor

人血小板 Fc(γ) 受体的生物学

基本信息

批准号：
6741160
负责人：
Alan D Schreiber
金额：
$ 32.33万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2003
资助国家：
美国
起止时间：
2003-04-01 至 2008-03-31
项目状态：
已结题

项目摘要

The human platelet Fcgamma receptor plays an important role in several hematologic disorders characterized by thrombocytopenia, thrombosis or vasculitis. Over the past 15 years, knowledge of the platelet Fcgamma receptor has grown. Aspects of its genetics, regulated expression and structure/function relationships, as well as its function in rive in immune pathology, have been studied by our group and others. The long term goai of our project is to more fully decipher the molecular mechanisms underlying piatelet Fcgamma, receptor biology in order to provide safer and more rational therapy for the immune platelet disorders, in addition, studies of the genetics, regulated expression, and signaling pathways of the platelet Fcgamma receptor remain synergistic with the other projects of our Program Project. The Specific Aims of this proposal are: 1. To examine the role of platelet FcgammaRIIA vs macrophage FcgammaRIIA in immune clearance in vivo. Our hypothesis is that the expression of FcgammaRllA ptays a major rote in regulating the fate of immune complexes in vivo, and that abrogation of ptatelet Fcgamma receptors, despite continued macrophage expression, will lead to aberrant clearance of immune complexes. Platetet-specific FcgammaRIIA transgenic mice as well as macrophage-specific FcgammaRIIA transgenic mice will be generated by use of DNA constructs with celt-specific promoter sequences appended to the coding region of the FcgammaRIIA gene. 2. To examine the regulation of expression of the platelet Fcgamma receptor. The level of platetet FcgammaRIIA correlates with its function in health and disease. Our hypothesis is that genetic variation in FcgammaRllA gene regulatory sequences, such as the promoter single nucleotide polymorphisms (SNPs) we recently identified, determine differences in the level of FcgammaRIlA expression. The mechanism of the SNP effects on FcgammaRllA expression will be studied in vitro with transfected reporter genes driven by genetic isoforms of the FcgammaRllA gene in megakaryocytic ceils, and in vivo in new transgenic mouse lines created with FcgammaRlIA variants. 3. To examine the role of Cbl in immune clearance, endocytosis and platelet activation. We have established the importance of Cbl in FcgammaRIIA mediated endocytosis in vitro and have crossbred Cbl knockout mice to our FcgammaRIIA transgenic mice. Our hypothesis is that Cbl is important for both FcgammaRIIA endocytosis in rive and FcgammaRIIA subcellutar localization. Continued progress in platelet Fcgamma, receptor biology should permit better diagnosis and therapy for patients with immune ptatelet disorders.

人血小板FCGAMMA受体在以血小板减少症，血栓形成或血管炎为特征的几种血液学疾病中起重要作用。在过去的15年中，对血小板FCGAMMA受体的了解已增强。我们的组和其他人已经研究了其遗传学，调节的表达和结构/功能关系及其在免疫病理学中的功能。我们项目的长期goai是更完全破译piatelet fcgamma的分子机制，《受体生物学》中的分子机制为了为免疫血小板疾病提供更安全，更合理的治疗，此外，还研究了遗传学，调节表达和血小板FCGAMMA受体的信号传导途径，与我们计划项目的其他项目保持协同作用。该提案的具体目的是：1。检查血小板fcmariia vs巨噬细胞在体内免疫清除率中的作用。我们的假设是，fcgammarlla ptays的表达在调节体内免疫复合物的命运方面的主要死记硬背，并废除了ptatelet 尽管巨噬细胞表达持续，但FCGAMMA受体仍会导致免疫复合物的异常清除。通过使用添加到fcgmammariia基因的编码区域的DNA构建体，将通过使用具有凯尔特特异性启动子序列的DNA构建体来生成降低的特异性FCGAMMARIIA转基因小鼠以及巨噬细胞特异性的FCGAMMARIIA转基因小鼠。 2。检查血小板FCGAMMA受体表达的调节。血小板的水平与其在健康和疾病中的功能相关。我们的假设是，我们最近确定的fcgammarlla基因调节序列的遗传变异，例如启动子单核苷酸多态性（SNP），确定fcgammarila表达水平的差异。将在巨核细胞天花板中由fcgammarlla基因的遗传同工型驱动的转染的记者基因，在体外研究SNP对FCGAMMARLALA表达的作用的机制，并在新的转基因小鼠系中用FCGAMMARLIA VARIANTS创建的新转基因小鼠。 3。检查CBL在免疫清除，内吞作用和血小板激活中的作用。我们已经确定了CBL在体外介导的内吞作用中的重要性，并将CBL敲除小鼠越过我们的Fcgammariia转基因小鼠。我们的假设是，CBL对于Rive和Fcgammariia subcellutar定位中的Fcgammariia内吞作用很重要。血小板FCGAMMA，受体生物学的持续进展应允许对免疫颅骨疾病患者更好的诊断和治疗。