Molecular characterization of human ANCA and antigen

抗中性粒细胞胞浆自身抗体（ANCA）于1982年首次被描述。我们在1988年报道了ANCA与坏死性肾小球肾炎（GN）的关联，并确认了髓过氧化物酶(MPO)-ANCA。从那时起，对许多问题有了实质性的了解，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GN和小血管炎（SVV）的临床和病理关系；3) ANCA参与血管炎症的发病机制。尽管ANCA领域取得了这些进展，但对于人类ANCA自身免疫反应的来源或在疾病发病或疾病复发期间引发自身免疫反应的精确抗原表位知之甚少。这个项目有三个具体目标。第一个目的是研究人PR3和MPO-ANCA免疫球蛋白基因的表达。我们假设MPO- anca和PR3- anca的表达依赖于特定的轻链和重链的使用，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。我们开发了一种从单个B细胞扩增信息的技术，允许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ANCA-GN发病和复发期间MPO和PR3的特异性表位。表位在发病和复发时的精细特异性是相同的吗？我们将MPO和PR3的克隆片段导入表达载体进行研究。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免疫反应的新的一般理解。众所周知，从DNA的反义链翻译而来的肽具有很强的选择性和亲和力。这个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来支持ANCA不仅与PR3反应，而且还与PR3的互补肽反应的新概念。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？我们将拥有探索这种模式所需的所有试剂。该项目将在疾病发病和疾病复发期间解剖人类ANCA和ANCA抗原。我们将确定分子识别理论是否适用于人类ANCA免疫反应，因为ANCA不仅可以对PR3和MPO起反应，还可以对这些ANCA抗原的互补肽起反应。

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.