THE MICROBIOTA AND MUCOSAL IMMUNE RESPONSES IN THE DEVELOPMENT OF ASTHMA

哮喘发生过程中的微生物群和粘膜免疫反应

• 批准号: 9211283
• 负责人: Andrew Leon Kau
• 金额: $ 16.29万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9211283
• 关键词: 8 year old; Acute; Algorithms; Allergic; Allergic Disease; Allergic inflammation; Animals; Antibodies; Antigens; Asthma; Bacteria; Bilateral; Binding; C57BL/6 Mouse; Cells; Child; Collection; Communities; Data; Data Set; Developed Countries; Developing Countries; Development; Diagnostic; Disease; Environment; Environmental Risk Factor; Extrinsic asthma; Flow Cytometry; Genetic; Germ-Free; Gnotobiotic; Grant; Habitats; House mice; Housing; Human; Hypersensitivity; Immune; Immune System Diseases; Immune response; Immune system; Immunoglobulin A; Individual; Inflammation; Intervention; Lead; Life Style; Lung; Lung diseases; Measurement; Microbe; Mucosal Immune Responses; Mus; Organism; Ovalbumin; Pathogenesis; Phenotype; Play; Predisposing Factor; Predisposition; Prevalence; Prevention strategy; Protocols documentation; RNA, Ribosomal, 16S; Respiratory System; Respiratory tract structure; Role; Sampling; Severities; Source; Specimen; Spleen; Surface; Techniques; Testing; Therapeutic; Time; Tissues; Transplantation; Variant; Vendor; airway inflammation; airway obstruction; allergic airway inflammation; allergic response; antigen challenge; asthmatic; base; disorder prevention; expectation; experimental study; follow-up; gut microbiota; interest; lymph nodes; member; microbial; microbial community; microbiota; mouse model; novel therapeutic intervention; prevent; public health relevance; respiratory; response; transcriptome sequencing; treatment strategy

 DESCRIPTION (provided by applicant): Asthma is a common allergic disorder characterized airway inflammation and obstruction. Though the prevalence of allergic diseases such as asthma is increasing, the reasons are incompletely understood. Environmental, rather than genetic, factors are thought to be primarily responsible, in part because of the association of allergy with Western lifestyles. This project will examine the hypothesis that the respiratory trac and gut microbiota is a key factor in conferring susceptibility or protection to allergic diseases, including asthma. Conventionally-raised and gnotobiotic mouse models of asthma will be used to test the hypothesis that a subset of bacteria, recognized by the immune system, is responsible for modulating susceptibility to asthma. The microbiota has previously been demonstrated to play a role in asthma pathogenesis in mice, but little is known about which microbes are responsible or even where (which body habitat) these organisms reside. In the first aim of this grant, mice from various vendors with different microbiota will be screened for microbial communities that predispose to allergic inflammation of their airways. Asthma will be induced by ovalbumin sensitization followed by antigen challenge. Severity of asthma in these animals will be determined by the degree of airway obstruction and tissue inflammation in their lungs. Their respiratory and intestinal microbiota will then be characterized by bacterial 16S rRNA sequencing, and BugFACS, a technique that allows isolation and identification of viable bacteria based on their binding to immunoglobulin A (IgA), the major antibody produced at mucosal surfaces. I will identify candidate bacterial strains that impact asthma phenotypes, initially by co-housing two types of mice - those harboring a microbiota associated with severe asthma and those with a microbiota associated with mild disease. Microbial source tracking algorithms, applied to 16S rRNA datasets generated from gut and respiratory tract microbiota, will be used to correlate observed changes in asthma severity upon co-housing with uni- or bilateral invasion of bacterial strains between cagemates. I will then transplant cultured invasive strains into the respiratory tract and/or gut of germ-free mice to establish whether these strains are causally related to asthma severity. In the second aim, a small group of well phenotyped 6-8 year old children, with and without asthma, will be sampled to characterize their respiratory and fecal microbiota by 16S rRNA sequencing and BugFACS. Representative respiratory tract and gut microbial communities will be transplanted from a) a representative asthmatic donor during an acute exacerbation, b) the same asthmatic at baseline, and c) a representative healthy non-asthmatic patient, into germ-free mice. Asthma will be induced in the recipient gnotobiotic mice that will then be characterized as described above. These aims will help dissect the relative contributions of respiratory tract and gut microbiota to disease pathogenesis and provide an approach for identifying bacterial strains that may have diagnostic and therapeutic utility.

 描述（应用程序提供）：哮喘是一种常见的过敏性疾病，表征了气道注射和客观。尽管过敏性疾病（例如哮喘）的患病率正在增加，但原因却不完全理解。环境而不是遗传因素被认为是主要的责任，部分原因是过敏与西方生活方式的关联。该项目将研究以下假设：呼吸道trac和肠道菌群是会议易感性或对过敏性疾病的保护的关键因素， 包括哮喘。哮喘的传统饲养和gnotobiotic小鼠模型将用于检验以下假设：免疫系统识别的细菌子集负责调节哮喘的易感性。先前已证明微生物群在小鼠的哮喘发病机理中发挥作用，但是对哪些微生物负责，甚至在哪里（哪个身体栖息地）居住的地方知之甚少。在这笔赠款的第一个目的中，将筛选来自各种微生物群的各种供应商的小鼠，以筛查易于过敏炎症的微生物群落。通过抗原挑战跟随卵蛋白的感觉诱导哮喘。这些动物哮喘的严重程度将取决于肺中的气道异常和组织注射程度。然后，它们的呼吸道和肠道菌群将以细菌16S rRNA测序以及BUGFACS为特征，该技术允许基于它们与免疫球蛋白A（IGA）的结合来隔离和鉴定可有效细菌，这是在粘膜表面产生的主要抗体。我将确定影响哮喘表型的候选细菌菌株，最初是由两种类型的小鼠组合的小鼠 - 那些具有与严重哮喘有关的菌群和与轻度疾病相关的微生物群有关的小鼠。微生物源跟踪算法应用于由肠道和呼吸道微生物群产生的16S rRNA数据集，可用于将观察到的哮喘严重程度与单次或双侧侵入细菌菌株之间的哮喘严重程度变化相关联。然后我将移植培养的侵入性 无菌小鼠的呼吸道和/或肠道的菌株确定这些菌株是否意外与哮喘严重程度相关。在第二个目标中，一小群具有和没有哮喘的良好表现为6-8岁的孩子将通过16S rRNA测序和Bugfacs来表征其呼吸和粪便微生物群。代表性的呼吸道和肠道微生物群落将从a）急性加重期间的代表哮喘供体移植，b）基线时相同的哮喘性，c）代表性的健康的非asthmatoration患者，无菌小鼠。哮喘将在受体gnotobiotic小鼠中诱导，然后如上所述。这些目标将有助于剖析呼吸道和肠道菌群对疾病发病机理的相对贡献，并提供一种方法来鉴定可能具有诊断和治疗效用的细菌菌株。