Role of unique ADP-ribosylating vacuolating Mycoplasma pneumoniae toxin in asthma

描述(由申请人提供)： 圣安东尼奥/达拉斯哮喘和过敏性疾病合作研究中心是一个综合性、协作性和创新性的多学科合作研究中心，旨在研究一种独特的肺炎支原体毒素在哮喘和相关呼吸道疾病中的作用。这种毒素，命名为社区获得性呼吸窘迫综合征毒素(CADS TX)，显著复制了伴随肺炎支原体感染的促炎细胞因子/趋化因子特征和组织病理学。这个由圣安东尼奥的德克萨斯大学健康科学中心和达拉斯的德克萨斯大学西南医学院组成的联盟结合了4个项目，这些项目侧重于基础、临床和动物建模策略，以及2个支持核心(行政和病理学)，以带来一种全新的方法来定义肺炎支原体与哮喘发病机制之间的关系。已积累了35年的大量文献将肺炎支原体与哮喘的发病、恶化和慢性化联系起来，但还没有一个支原体毒力决定因素或支原体分子被证明是症状和相关病理的媒介。由于缺乏明确的肺炎支原体致病因素，这极大地阻碍了对肺炎支原体如何影响呼吸道疾病的发展和进展的了解。这在哮喘等复杂疾病中尤其具有挑战性，在这些疾病中，遗传、免疫学、传染病和环境变量似乎会影响疾病的发展和进展。AADCRC的一个主要重点是将ADP-核糖化、空泡化肺炎支原体卡片TX(项目4)的生化、分子和免疫学特性与哮喘患者的诊断和治疗(项目3和4)直接联系起来。通过这样做，我们希望证明CARDS TX是人类(项目3)和实验感染或醉酒小鼠(项目1和2)哮喘相关病理生物学的关键介质。因此，我们打算：(A)利用患者的鼻腔灌洗、痰和血清样本，通过新型有效的CARD TX靶向诊断评估(ELISA法、免疫组织化学、抗原捕获和PCR方法)，将CARD TX与哮喘发病机制直接联系起来；(B)利用肺炎支原体感染和CADS TX中毒的小鼠模型，检测哮喘的急性和慢性阶段、治疗干预措施以及CARDS TX对呼吸道高反应性的影响；(C)进一步表征CADS TX的ADP核糖化活性，并建立有效而快速的诊断方法，以辅助治疗和控制哮喘及相关病理。每个项目和核心的主要研究人员在哮喘、与呼吸道相关的病理学、免疫致病机制、肺炎支原体生物学和毒力以及合作和联合发表的历史方面都有很强的跟踪记录和专业知识。 项目1：新型肺炎支原体卡氏毒素作为小鼠呼吸道功能障碍的中介(Hardy，R.) 描述(由申请人提供)： 越来越多的证据表明肺炎支原体呼吸道感染与哮喘的发病、加重和慢性化有关。然而，涉及这一环节的致病微生物学机制还没有得到很好的表征。具有重要意义的是，巴斯曼博士和卡南博士现在已经鉴定出一种新的肺炎支原体毒素，CARDS TX。我们的研究团队(Baseman、Coalson、Dube、Kannan、Peters和Hardy博士)有初步证据表明，卡片TX在呼吸道炎症、呼吸道阻塞、呼吸道高反应性与呼吸道肺炎支原体感染相关的致病因素中起致病作用。这项拟议研究的假设是，CARDS TX介导肺炎支原体引起急性哮喘加重的能力，并对支原体呼吸道感染的长期有害影响负责。此外，我们假设针对卡介苗TX的治疗干预将改善肺炎支原体相关的反应性呼吸道疾病和哮喘。简而言之，这些研究的具体目的是：1)了解激活的CARDS Tx在肺炎支原体呼吸道感染中观察到的呼吸道阻塞、高反应性和炎症中的具体作用；2)确定对CADS Tx的宿主免疫反应是否对肺炎支原体感染的呼吸道表现具有保护作用；以及3)确定细菌蛋白质合成抑制剂治疗对肺炎支原体呼吸道感染中CARDS Tx蛋白产生的影响。这些研究的长期目标是开发疾病改进策略，以治疗患有支原体相关反应性呼吸道疾病和哮喘的儿童和成人。本项目专注于在我们建立的肺炎支原体呼吸道感染的急性和慢性小鼠模型中研究新型肺炎支原体毒素CHARDS TX，在该模型中，呼吸道炎症、呼吸道阻塞和呼吸道高反应性是我们实验室先前已确定的特征。将BALB/c小鼠暴露于肺炎支原体(野生型和CADS TX缺失突变体)或重组CARD TX，以确定CADS TX对肺炎支原体感染的呼吸道表现的贡献。此外，针对卡介苗TX的治疗干预措施将在我们的小鼠模型中进行评估，目标是翻译适用于儿童和成人中与肺炎支原体相关的反应性呼吸道疾病和哮喘的治疗。

DESCRIPTION (provided by applicant): The San Antonio/Dallas Asthma and Allergic Diseases Cooperative Research Center represents an integrative, collaborative and innovative multidisciplinary effort to investigate the role of a unique Mycoplasma pneumoniae toxin in asthma and related airway diseases. This toxin, designated Community Acquired Respiratory Distress Syndrome Toxin (CARDS TX) remarkably replicates the proinflammatory cytokine/chemokine profiles and histopathology that accompany M. pneumoniae infection. This consortium between The University of Texas Health Science Center at San Antonio and The University of Texas Southwestern Medical School in Dallas combines 4 projects, which focus on basic, clinical and animal modeling strategies, with 2 support cores (administrative and pathology) to bring a totally new approach to defining the relationship between M. pneumoniae and the pathogenesis of asthma. A substantial literature, which has accumulated over thirty-five years, connects M. pneumoniae to onset, exacerbation, and chronicity of asthma, yet no single mycoplasma virulence determinant, or mycoplasma molecule for that matter, has been shown to be a mediator of symptoms and associated pathologies. This lack of definable M. pneumoniae pathogenic factors has greatly hampered an understanding of how M. pneumoniae influences the development and progression of airway diseases. This is especially challenging in complex diseases like asthma, where genetic, immunologic, infectious and environmental variables appear to affect disease development and progression. A major focus of the AADCRC is to directly link the biochemical, molecular and immunological properties of the ADP-ribosylating, vacuolating M. pneumoniae CARDS TX (Project 4), to diagnosis and treatment of asthmatic patients (Projects 3 and 4). By so doing, we hope to demonstrate that CARDS TX is a key mediator of asthma-associated pathobiology in humans (Project 3) and in experimentally infected or intoxicated mice (Projects 1 and 2). Therefore, we intend to (a) directly connect CARDS TX to asthma pathogenesis through novel and effective CARDS TX-targeted diagnostic assessments (ELISA, immunohistochemistry, antigen capture and PCR methodologies) using patient's nasal lavage, sputum and serum samples; (b) use mouse models of M. pneumoniae infection and CARDS TX intoxication to examine both acute and chronic stages of asthma and therapeutic interventions as well as the impact of CARDS TX on airway hyper-reactivity; and (c) further characterize ADP-ribosylating activities of CARDS TX and develop effective and rapid diagnostics to assist in the treatment and control of asthma and related pathologies. The key investigators of each project and core have strong track records and expertise in asthma, airway-related pathologies, immunopathogenesis and M. pneumoniae biology and virulence as well as a history of collaboration and co-publication. PROJECT 1: Novel Mycoplasma pneumoniae CARDS Toxin as Mediator of Airway Dysfunction in Mice (Hardy, R.) DESCRIPTION (provided by applicant): There is growing evidence linking M. pneumoniae respiratory infection and the inception, exacerbation, and chronicity of asthma in a subset of asthmatics. However, the pathogenic microbiologic mechanisms involved in this link have not been well characterized. Of great significance, Drs. Baseman and Kannan have now identified a novel M. pneumoniae toxin, CARDS TX. Our consortium of researchers (Drs. Baseman, Coalson, Dube, Kannan, Peters, and Hardy) has preliminary evidence of CARDS TX playing a pathogenic role in the airway inflammation, airway obstruction, airway hyper-reactivity associated with respiratory M. pneumoniae infection. The hypothesis for the proposed research is that CARDS TX mediates the ability of M. pneumoniae to induce acute asthma exacerbations and is responsible for the deleterious long-term effects of mycoplasma respiratory tract infection. In addition, we hypothesize that therapeutic interventions directed against CARDS TX will ameliorate M. pneumoniae-associated reactive airway disease and asthma. Briefly, the Specific aims are to 1) understand the specific contribution of active CARDS TX to the airway obstruction, hyper-reactivity, and inflammation observed in M. pneumoniae respiratory infection, 2) determine if the host immune response to CARDS TX is protective against the respiratory manifestations of M. pneumoniae infection, and 3) determine the effect of bacterial protein synthesis inhibitor therapy on CARDS TX protein production in M. pneumoniae respiratory infection. The long-term goal of these investigations is to develop disease modifying strategies to treat children and adults with mycoplasma-associated reactive airway disease and asthma. This project focuses on investigating the novel M. pneumoniae toxin, CARDS TX, in our established acute and chronic murine model of M. pneumoniae respiratory infection in which airway inflammation, airway obstruction, and airway hyper-reactivity have been previously characterized by our laboratory. BALB/c mice will be exposed to M. pneumoniae (wild-type and CARDS TX null mutant) or recombinant CARDS TX to determine the contribution of CARDS TX to the airway manifestations of M. pneumoniae infection. In addition, therapeutic interventions directed against CARDS TX will be assessed in our murine model with the goal of translational applicability to the treatment of reactive airway disease and asthma associated with M. pneumoniae in children and adults.