MODELING OF PLATELET ALLOANTIGENS

血小板同种抗原的建模

• 批准号: 6389866
• 负责人: Emily Barron-Casella
• 金额: $ 11.34万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6389866
• 关键词: active immunization; antibody formation; antibody specificity; antigen antibody reaction; antigen presentation; chimeric proteins; disease /disorder model; disulfide bond; fibrinogen receptors; glycoproteins; histocompatibility; human tissue; integrins; isoantibody; isoantigen; laboratory mouse; model design /development; monoclonal antibody; platelets; protein engineering; protein structure function; purpura; recombinant proteins; site directed mutagenesis; thrombocytopenia

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.

这个新的R29提案的长期目标是了解 涉及的抗原决定簇和免疫要求 同种免疫 这项建议的重点是人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 等位基因之间产生GP IIIa的33位多态性， 纤维蛋白原受体的组成部分。 HPA-1a的纯合子编码一个 33位为亮氨酸; HPA-1b纯合子编码脯氨酸。 HPA-1是 两种出血性疾病的最常见原因，新生儿同种免疫 血小板减少症和输血后紫癜。 在这两种疾病中， 针对HPA-1a GPIIIa制备抗HPA-1a抗体，导致 血小板减少症。 在这项提议中，实验旨在进一步 探讨HPA-1a的表达情况，并验证其建立小鼠模型的可行性。 在 为了实现这一目标，关于HPA-1系统的重要问题将是 处理。 具体目标是：（1）进一步明确结构 HPA-1a抗原性的要求，2）确定结构是否 HPA-1a抗原性的要求可以在鼠GPIIIa中重建， 3)探讨建立HPA-1a动物模型的可行性 通过首先建立表达HPA-1a的鼠细胞系进行同种异体免疫 纤维蛋白原受体 通过操纵含有人类基因的重组蛋白， GPIIIa结构域，多态性的作用，N端三个二硫键 HPA-1a抗原性中的长链Cys 5 Cys 435二硫键 将被评估。 这些信息将用于重建类似HPA-1a的 小鼠GPIIIa中的抗原和引发抗HPA-1a的标准 将确定小鼠中的反应。 HPA-1a小鼠GPIIIa的能力， 组装成纤维蛋白原受体并结合转染细胞中的配体 还将测试巨核母细胞。