Anti-myeloperoxidase autoantibody response

抗中性粒细胞胞浆抗体（ANCA）是一种针对髓过氧化物酶（MPO）和蛋白酶3（PR 3）的抗体，在少免疫性坏死性肾小球肾炎和小血管炎患者中普遍存在。参与这些自身抗体产生的因素仍然未知。我们推测ANCA及其相关疾病的低发病率部分是由于特定V区基因重组、特定体细胞突变或两者的要求，并且小鼠中抗MP抗体的表达是耐受性崩溃的结果。来自未免疫的SCG/KJ小鼠的抗MPO抗体的研究揭示了Vk基因使用的限制，并提供了MPO是抗MPO应答中的驱动抗原的证据。本项目的两个具体目标是（1）评估小鼠抗MPO自身抗体的亲和力，和（2）研究小鼠抗MPO应答的调节。目的1将通过共表达抗MPO衍生的H或L链与多种非抗MPO衍生的链，并通过使用定点诱变引入或去除特定的体细胞突变来实现。所得抗体的特异性和亲合力将通过基于ELISA和生物传感器的技术测量。目标2将通过产生仅抗MPO轻链、仅抗MPO重链和两者的转基因小鼠来实现。这种方法将允许研究在其成熟的抗MPO B细胞的水平受到调节。这两个目标将有助于填补一个重要的空白，我们目前的知识，这些机制参与的产生和调节的抗MPO自身免疫反应。

An anti-neutrophil cytoplasmic antibodies (ANCA), directed toward myeloperoxidase (MPO) and proteinase 3 (PR3), are detected in the majority of patients with pauci-immune necrotizing glomerulonephritis and small vessel vasculitis. The factors involved in the generation of these autoantibodies remain unknown. We hypothesize that the low incidence of ANCA and their associated diseases is in part due to requirements for particular V region gene recombinations, specific somatic mutations, or both and that the expression of anti-MP antibodies in mice is the result of a breakdown in tolerance. The study of anti-MPO antibodies derived from unimmunized SCG/KJ mice revealed a restriction in Vk gene use, and provides evidence that MPO is a driving antigen in the anti-MPO response. The two specific aims of this project are to (1) assess the affinity of murine anti-MPO autoantibodies, and (2) study the regulation of the anti-MPO response in mice. Aim 1 will be pursued by co-expressing anti-MPO derived H or L chains with a variety of non-anti-MPO-derived chains, and by introducing of removing specific somatic mutations using site-directed mutagenesis. The specificity and avidity of the resulting antibodies will be measured by ELISA and Biosensor based techniques. Aim 2 will be approached by the generation of mice transgenic for anti- MPO-light chain only, heavy chain only, and both. This approach will allow to study at which level of their maturation anti-MPO B cells are regulated. These two aims will help fill an important gap in our current knowledge of these mechanisms involved in the generation and regulation of the anti- MPO autoimmune responses.