Anti-myeloperoxidase autoantibody response

针对髓过氧化物酶（MPO）和蛋白酶3 （PR3）的抗中性粒细胞胞质抗体（ANCA）在大多数缺乏免疫坏死性肾小球肾炎和小血管炎患者中检测到。这些自身抗体产生的相关因素尚不清楚。我们假设，ANCA及其相关疾病的低发病率部分是由于对特定V区基因重组、特定体细胞突变或两者兼而有之的要求，而小鼠体内抗mp抗体的表达是耐受性下降的结果。来自未免疫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反应的驱动抗原的证据。本项目的两个具体目的是：(1)评估小鼠抗mpo自身抗体的亲和力，(2)研究小鼠抗mpo反应的调控。目标1将通过与各种非抗mpo衍生链共同表达抗mpo衍生的H链或L链，并通过引入位点定向诱变去除特定的体细胞突变来实现。所得抗体的特异性和亲切度将通过ELISA和基于生物传感器的技术来测量。目的2将通过培养抗mpo的转基因小鼠——仅轻链、仅重链和两者兼有。这种方法将允许研究在哪个水平的成熟抗mpo B细胞被调节。这两个目标将有助于填补我们目前对这些机制的知识的重要空白，这些机制涉及抗MPO自身免疫反应的产生和调节。

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.