Identifying Kawasaki Disease-Specific Antibodies and Antigens

川崎病（KD）是发达国家儿童获得性心脏病的主要病因。 在Ann & Robert H.在芝加哥Lurie儿童医院，我们每年诊断60-70例新病例， 儿童医院每年诊断出数十名KD患者。KD是一种急性发热性疾病， 通常在传染病中观察到，可导致冠状动脉瘤， 在6个月以下的婴儿中严重，在5岁以下的幼儿中发病率最高，非常罕见 在成年人中，发生在疾病的地理波浪式传播的流行病中，并且很少复发。这些具体 KD的流行病学特征最好解释为感染了一种普遍存在的感染因子， 无症状，但可导致遗传易感儿童的KD。没有已知的传染源与 关于KD我的实验室报告了抗原驱动的动脉伊加免疫反应在急性KD。在先前的研究中， 我们用寡克隆免疫球蛋白α重链和随机轻链制备了合成抗体， KD动脉组织cDNA。从组织cDNA中不能确定同源轻链和重链对 提供给我们。我们最初的KD合成抗体检测到的抗原在胞浆内包涵体， 免疫组化显示，急性KD而非婴儿对照支气管上皮细胞，但亲和力不足 以在免疫沉淀分析中结合抗原。在其他研究中，我们发现I型干扰素诱导的基因 在KD患者的肺和冠状动脉中上调，与抗病毒免疫应答一致。 基于这些数据，我们假设KD是一种免疫介导的疾病， 易受感染的儿童感染了一种目前尚未确认的病毒。在本提案中，我们将使用新的方法， 从单细胞分选的外周血中快速克隆和生产抗原特异性合成抗体 浆母细胞，允许鉴定单个浆母细胞中的同源轻链和重链， 产生高亲和力抗体。我们计划制备一组KD特异性单克隆抗体， 用它们来鉴定KD特异性抗原。在初步研究中，我们发现了一个寡克隆的，抗原驱动的 急性KD患者外周血中的浆母细胞反应，该患者发生了冠状动脉瘤。 我们使用来自最普遍的寡克隆抗体的同源轻链和重链制备合成抗体。 浆母细胞该抗体结合来自其他KD患者的组织中的抗原。这项建议 包括一个由KD、病毒学、免疫学和生物统计学专家组成的多学科团队， 以下具体目的：1）鉴定和克隆KD中外周血浆母细胞反应，和2）鉴定 寡克隆KD外周血浆母细胞的抗原靶标。KD特异性抗体的鉴定和 抗原是确定KD病因，改善诊断和治疗， 预防，目标是从长期减少儿科医疗保健费用、发病率和死亡率。 冠状动脉瘤的后果是在幼年时期获得的。

Kawasaki Disease (KD) is the leading cause of acquired heart disease in children in developed nations. At Ann & Robert H. Lurie Children's Hospital of Chicago, we diagnose 60-70 new cases/year, and most US children's hospitals diagnose scores of KD patients annually. KD is an acute febrile illness with clinical features commonly observed in infectious diseases, can result in coronary artery aneurysms that can be particularly severe in infants <6 months of age, has highest incidence in young children <5 years of age, is extremely rare in adults, occurs in epidemics with geographic wavelike spread of illness, and only rarely recurs. These specific epidemiologic features of KD are best explained by infection with a ubiquitous infectious agent that is usually asymptomatic, but can result in KD in genetically susceptible children. No known infectious agent is associated with KD. My laboratory reported an antigen-driven arterial IgA immune response in acute KD. In prior studies, we made synthetic antibodies using oligoclonal immunoglobulin α heavy chains and random light chains from KD arterial tissue cDNA. Cognate light and heavy chain pairs could not be determined from the tissue cDNA available to us. Our original KD synthetic antibodies detected antigen in intracytoplasmic inclusion bodies in acute KD but not infant control bronchial epithelium by immunohistochemistry, but were not of sufficient affinity to bind antigen in immunoprecipitation assays. In other studies, we found that type I interferon-induced genes were upregulated in lungs and coronary arteries of KD patients, consistent with an antiviral immune response. Based on these data, we hypothesize that KD is an immune-mediated illness occurring in genetically predisposed children infected with a presently unidentified virus. In this proposal we will use new methods to rapidly clone and produce antigen-specific synthetic antibodies from single cell sorted peripheral blood plasmablasts, allowing identification of cognate light and heavy chains in individual plasmablasts and production of high-affinity antibodies. We plan to prepare a panel of KD-specific monoclonal antibodies and use them to identify KD-specific antigens. In preliminary studies, we identified an oligoclonal, antigen-driven plasmablast response in peripheral blood of an acute KD patient who developed a coronary artery aneurysm. We prepared synthetic antibody using cognate light and heavy chains from the most prevalent oligoclonal plasmablasts from this patient. This antibody binds to antigen in tissues from other KD patients. This proposal includes a multidisciplinary team of experts in KD, virology, immunology, and biostatistics to perform the following specific aims: 1) Identify and clone the peripheral blood plasmablast response in KD, and 2) Identify antigenic targets of oligoclonal KD peripheral blood plasmablasts. Identification of KD-specific antibodies and antigens is an important step toward identifying KD etiology, improving diagnosis and treatment, and enabling prevention, with the goals of reducing pediatric health care costs, morbidity, and mortality from the long-term consequences of coronary artery aneurysms that are acquired during young childhood.