MODELING OF PLATELET ALLOANTIGENS

描述：这个新的R29提案的长期目标是理解 涉及的抗原决定因素和免疫学要求 同种异体免疫。这项提案关注的是人类血小板同种异体抗原1 (HPA-1)。HPA-1是一个双等位基因系统；单核苷酸差异 等位基因之间在GP IIIa第33位产生多态 纤维蛋白原受体的组成部分。HPA-1a纯合子编码a 33位亮氨酸；HPA-1b纯合子编码脯氨酸。HPA-1是 两种出血性疾病最常见的原因是新生儿同种免疫 血小板减少症和输血后紫癜症。在这两种疾病中， 抗HPA-1a抗体是针对HPA-1a GPIIIa制造的，导致 血小板减少症。在这项提案中，实验旨在进一步 探索HPA-1a并测试制作小鼠模型的可行性。在……里面 为了实现这一目标，关于HPA-1系统的重要问题将是 地址。具体目标是1)进一步界定结构性的 对HPA-1a抗原性的要求，2)确定结构是否 对HPA-1a抗原性的要求可以在小鼠GPIIIa中重建，并且 3)建立HPA-1a动物模型的可行性 首先建立表达HPA-1a的小鼠细胞系进行同种异体免疫 纤维蛋白原受体。通过操纵含有人的重组蛋白 GPIIIa结构域的多态作用，N端三个二硫键 键，以及具有HPA-1a抗原性的长程Cys5-Cys435二硫键 将会被评估。此信息将用于重建类似HPA-1a的 小鼠GPIIa抗原及其诱导抗HPA-1a抗体的标准 小鼠的反应将被确定。HPA-1a小鼠GPIIa表达的能力 重组成纤维蛋白原受体并与转染体结合 巨核细胞也将接受测试。

DESCRIPTION: The long-term goal of this new R29 proposal is to understand the antigenic determinants and immunologic requirements involved in alloimmunization. This proposal focuses on human platelet alloantigen 1 (HPA-1). HPA-1 is a biallelic system; a single nucleotide difference between alleles creates a polymorphism at position 33 of GP IIIa, a component of the fibrinogen receptor. Homozygotes for HPA-1a encode a leucine at position 33; homozygotes for HPA-1b encode proline. HPA-1 is the most common cause of two bleeding disorders, neonatal alloimmune thrombocytopenia and posttransfusion purpura. In both disorders, anti-HPA-1a antibodies are made against HPA-1a GPIIIa, leading to thrombocytopenia. In this proposal, experiments are designed to further explore the HPA-1a and test the feasibility of making a murine model. In pursuing this goal, important questions about the HPA-1 system will be addressed. The specific aims are 1) to further define the structural requirements for HPA-1a antigenicity, 2) to determine if the structural requirements for HPA-1a antigenicity can be recreated in murine GPIIIa, and 3) to test the feasibility of making an animal model of HPA-1a alloimmunization by first creating a murine cell line expressing an HPA-1a fibrinogen receptor. By manipulating recombinant proteins containing human GPIIIa domains, the role of the polymorphism, the three N-terminal disulfide bonds, and the long range Cys5 Cys435 disulfide bond in HPA-1a antigenicity will be evaluated. This information will be used to recreate an HPA-1a-like antigen in murine GPIIIa and the criteria for eliciting an anti-HPA-1a response in mice will be determined. The ability of HPA-1a murine GPIIIa to assemble into a fibrinogen receptor and bind ligand in transfected megakaryoblastic cells will also be tested.