Traffic-related air pollutants and respiratory tract microbiome in children

 描述（由申请人提供）：环境暴露、呼吸道微生物组和与哮喘和其他呼吸道疾病相关的免疫反应之间的相互作用尚未得到充分理解。高水平的交通相关空气污染物（TRAP）与儿童哮喘有关。TRAP可增加微生物对呼吸道上皮细胞的粘附并损伤上皮层，导致对微生物生长的敏感性增加。许多研究表明，改变的人类微生物群在哮喘病因学中的作用。此外，间接证据表明，呼吸道细菌感染可能在哮喘的发展中发挥作用。气道微生物群可能与儿童呼吸道中发育中的粘膜免疫系统的先天性和适应性臂相互作用，这在维持对过敏性免疫应答的耐受性方面至关重要。我们最近的数据显示，出生时接触交通相关颗粒物的增加与儿童期纵向喘息有关。我们假设，在生命早期暴露于TRAP显著改变了儿童呼吸道微生物的多样性，这种影响持续到青春期早期。在具体目标1中，我们将描述儿童时期暴露于高水平和低水平交通相关空气污染的青少年儿童的呼吸道微生物组。为此目的，将招募来自NIEHS资助的辛辛那提儿童过敏和空气污染研究（CCAAPS）现有队列的儿童。该队列在儿童暴露于TRAP和室内空气致敏原以及儿童从出生到12岁的呼吸系统健康方面得到了很好的表征。12-15岁的TRAP暴露将通过卡车和公共汽车交通暴露的土地利用回归模型进行估计。通过采集诱导痰标本，提取DNA，扩增细菌特异性PCR产物，对儿童呼吸道细菌组成、操作分类单位（OTU）和多样性指数进行表征（使用16 S rRNA引物），通过深度测序分析DNA序列，聚类并将Illumina MiSeq读数分配到操作分类单位（OTU）中，分析OTU，利用RDP数据库和流水线，以及MG-RAST和Qiime软件包进行细菌多样性测定。在具体目标2中，我们将评估细菌OTU、多样性指数和TRAP之间的关联。据我们所知，以前没有关于空气污染物对人体呼吸道微生物组影响的报道，特别是在儿童中。这个信息非常重要 了解空气污染、人体微生物组和儿童呼吸系统健康之间的相互作用。

 DESCRIPTION (provided by applicant): The interplay between environmental exposures, respiratory tract microbiome, and immune responses related to asthma and other respiratory diseases is not well understood. High levels of traffic-related air pollutants (TRAP) have been associated with children's asthma. TRAP can increase adherence of microorganisms to the epithelial cells of the respiratory tract and damage the epithelial layers resulting in increased susceptibility to microbial growth. Many studies suggest a role for altered human microbiota in the etiology of asthma. Furthermore, circumstantial evidence indicates that bacterial infections in the respiratory tract may play a role in asthma development. The airway microbiota may interact with the innate and adaptive arms of the children's developing mucosal immune system in the respiratory tract, which can be critically important in maintaining tolerance against allergc immune responses. Our recent data show that increased exposure to traffic-related particles at birth is associated with longitudinal childhood wheezing. We hypothesize that exposure to TRAP early in life significantly alters the diversity of microorganisms in the respiratory tract in chilren and this effect persists to early adolescence. In Specific Aim 1, we will characterize the respiratory tract microbiome of adolescent children exposed to high and low levels of traffic related air pollution during childhood. Children from the existing cohort of the NIEHS-funded Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) will be recruited for this purpose. This cohort is well characterized regarding childhood exposure to TRAP and indoor aeroallergens as well respiratory health of children from birth to age 12. TRAP exposure at ages 12-15 will be estimated by a land use regression (LUR) model of exposure to truck and bus traffic. Bacterial composition, operational taxonomic units (OTUs), and diversity indices in the respiratory tract of children will be characterized by collecting induced sputum samples, extracting DNA, amplifying bacteria-specific PCR products (using 16S rRNA primers), analyzing DNA sequences by deep sequencing, clustering and assignment of Illumina MiSeq reads into Operational Taxonomic Units (OTUs), analysis of OTUs, and determination of bacterial diversity by RDP database and pipeline, as well as MG-RAST and Qiime software packages. In Specific Aim 2, we will assess associations between bacterial OTUs, diversity indices, and TRAP. To our knowledge, there are no previous reports on the effects of air pollutants on the human respiratory tract microbiome, particularly among children. This information is critically important to understand the interaction between air pollution, human microbiome, and respiratory health among children.