Molecular characterization of human ANCA and antigen

人 ANCA 和抗原的分子表征

• 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
• 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
• 来源: https://reporter.nih.gov/project-details/6643646
• 关键词: antiidiotype antibody; autoantibody; clinical research; endopeptidases; glomerulonephritis; human subject; immunoglobulin genes; immunoglobulin idiotypes; immunoregulation; laboratory mouse; myeloperoxidase; necrosis; neutrophil; relapse /recurrence; transfection /expression vector

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.

1982年首次描述了抗中性嗜性胞质自身抗体（ANCA）。我们报道了1988年ANCA与坏死性肾小球肾炎（GN）的关联，并识别出髓过氧化物酶（MPO）-ANCA。从那时起，人们对许多问题进行了大量了解，包括：1）将ANCA抗原分离为MPO-ANCA或蛋白酶3（PR3）-ANCA； 2）ANCA与坏死性GN和小血管血管炎（SVV）的临床和病理关联； 3）ANCA参与血管炎症的发病机理。尽管ANCA社区的这些进展知之甚少，人们对人类ANCA自身免疫反应的推导或确切的抗原表位对于在疾病发作期间或疾病复发期间引起自身免疫反应很重要。该项目具有三个特定的目标。第一个目的研究人PR3和MPO-ANCA免疫球蛋白基因表达。我们假设MPO-ANCA和PR3-ANCA表达取决于特定的轻度和重链使用情况，并且MPO和PR3都在此自身免疫反应的成熟过程中选择抗原。我们开发了一种从单个B细胞扩增消息的技术，从而可以研究扩增的免疫球蛋白基因的体细胞突变。在第二个目标中，我们将研究疾病发作和ANCA-GN复发期间对MPO和PR3的特定表位。疾病发作过程中表位的良好特异性是否相同？我们将MPO和PR3的克隆片段纳入表达向量以进行这些研究。第三个目标是最令人兴奋的，可能会提供对自身免疫性和ANCA免疫反应的新一般理解。众所周知，从DNA的抗敏感链中翻译的肽结合了具有实质性选择性和亲和力的感觉蛋白质。该概念被表述为分子识别理论。我们已经开发了令人兴奋的初步数据，以支持新颖的概念，即ANCA不仅对PR3做出反应，而且还对PR3的互补肽做出了反应。对自身免疫反应的互补肽部分的免疫反应是否反应？ Pr3-anca和对偶像型抗IDiotypic关系的互补肽的抗体是吗？我们将拥有探索此范式的所有必要试剂。该项目将在疾病发作期间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不仅对PR3和MPO，还与肽互补的ANCA抗原反应。