Molecular characterization of human ANCA and antigen

人 ANCA 和抗原的分子表征

基本信息

批准号：
6643646
负责人：
Ronald J Falk
金额：
$ 16.72万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-09-01 至 2003-08-31
项目状态：
已结题

项目摘要

Anti-neutrophil cytoplasmic autoantibodies (ANCA) were first described in 1982. We reported the association of ANCA with necrotizing glomerulonephritis (GN) in 1988 and recognized myeloperoxidase (MPO)-ANCA. Since then, substantial insight into a number of issues has been gained including: 1) separation of ANCA antigens into MPO-ANCA or proteinase 3 (PR3)-ANCA; 2) clinical and pathological associations of ANCA with necrotizing GN and small vessel vasculitis (SVV); and 3) that ANCA participate in the pathogenesis of vascular inflammation. Despite these strides by the ANCA community little is known about the derivation of the human ANCA autoimmune response or the precise antigenic epitopes important in eliciting an autoimmune response during disease onset or during disease relapse. This project has three specific aims. The first aim studies the human PR3 and MPO-ANCA immunoglobulin gene expression. We hypothesize that MPO-ANCA and PR3-ANCA expression is dependent on specific light and heavy chain usage and that both MPO and PR3 are selecting antigens in the maturation of this autoimmune response. We developed a technique to amplify message from single B cells, allowing the study of somatic mutations of the amplified immunoglobulin genes. In the second aim, we will study specific epitopes on MPO and PR3 during disease onset and during relapse of ANCA-GN. Is the fine specificity of epitope usage during disease onset and relapse the same? We have clone fragments of MPO and PR3 into expression vectors to perform these studies. The third aim is the most exciting and may provide a new general understanding of autoimmunity and of the ANCA immune response in particular. It is known that peptides translated from the anti-sense strand of DNA bind to sense proteins with substantial selectivity and affinity. This concept is formulated as the molecular recognition theory. We have developed exciting preliminary data to support the novel concept that ANCA react not only with PR3, but also with complementary peptides to PR3. Is the immune response to the complementary peptide part of the autoimmune response? Are PR3-ANCA and antibodies to complementary peptides examples of an idiotypic anti-idiotypic relationship? We will have all the reagents necessary to explore this paradigm. The project will dissect human ANCA and ANCA antigens during disease onset and during disease relapse. We will ascertain whether the molecular recognition theory pertains to the human ANCA immune response in that ANCA may react, not only to PR3 and MPO, but to peptides complementary to these ANCA antigens.

抗中性粒细胞胞质自身抗体 (ANCA) 于 1982 年首次被描述。我们于 1988 年报道了 ANCA 与坏死性肾小球肾炎 (GN) 的关联，并认识到髓过氧化物酶 (MPO)-ANCA。从那时起，人们对许多问题有了深入的了解，包括：1) 将 ANCA 抗原分离成 MPO-ANCA 或蛋白酶 3 (PR3)-ANCA； 2）ANCA与坏死性肾小球肾炎和小血管炎（SVV）的临床和病理学关联； 3) ANCA参与血管炎症的发病机制。尽管 ANCA 界取得了这些进展，但人们对人类 ANCA 自身免疫反应的起源或在疾病发作或疾病复发期间引发自身免疫反应很重要的精确抗原表位知之甚少。该项目有三个具体目标。第一个目标是研究人类 PR3 和 MPO-ANCA 免疫球蛋白基因表达。我们假设 MPO-ANCA 和 PR3-ANCA 表达依赖于特定的轻链和重链使用，并且 MPO 和 PR3 都在这种自身免疫反应的成熟过程中选择抗原。我们开发了一种技术来放大来自单个 B 细胞的信息，从而可以研究放大的免疫球蛋白基因的体细胞突变。第二个目标是研究 ANCA-GN 发病和复发期间 MPO 和 PR3 上的特定表位。疾病发作和复发期间表位使用的精细特异性是否相同？我们将 MPO 和 PR3 的克隆片段放入表达载体中以进行这些研究。第三个目标是最令人兴奋的，可能会提供对自身免疫，特别是 ANCA 免疫反应的新的总体理解。众所周知，从 DNA 反义链翻译的肽以显着的选择性和亲和力与有义蛋白结合。这个概念被表述为分子识别理论。我们已经开发出令人兴奋的初步数据来支持这样的新概念：ANCA 不仅与 PR3 发生反应，而且还与 PR3 的互补肽发生反应。对互补肽的免疫反应是自身免疫反应的一部分吗？ PR3-ANCA 和互补肽抗体是独特型抗独特型关系的例子吗？我们将拥有探索这一范例所需的所有试剂。该项目将在疾病发作和疾病复发期间剖析人类 ANCA 和 ANCA 抗原。我们将确定分子识别理论是否与人类 ANCA 免疫反应有关，因为 ANCA 不仅可以与 PR3 和 MPO 反应，还可以与这些 ANCA 抗原的互补肽反应。