H. influenzae genes associated with COPD

描述(由申请人提供)： 项目摘要：慢性阻塞性肺病是环境因素、宿主免疫反应和微生物因素复杂相互作用的结果。流感嗜血杆菌定植于人体呼吸道，是与慢性阻塞性肺疾病相关的重要病原体。这项研究的总体目标是确定导致COPD发病的流感嗜血杆菌因子。这项提议所采用的基本原则是，流感嗜血杆菌在遗传上具有高度的变异性，自然选择在特定的细菌种群中保留了必要的基因。在具体目标1中，将描述从COPD患者和非COPD成人中分离的流感嗜血杆菌毒力基因的流行率。在特定的目标中，将确定另外两个分离自COPD患者和非COPD成人的流感嗜血杆菌的差异基因。这项基因发现工作将利用消减基因组杂交来鉴定与典型COPD流感嗜血杆菌菌株中存在但在典型共生菌株中缺失的基因相对应的流感嗜血杆菌DNA片段。将使用细菌基因组微阵列技术评估所产生的DNA片段在COPD和非COPD流感嗜血杆菌菌株中的流行率。此外，COPD相关DNA片段的相应基因将被定义和定位在流感嗜血杆菌染色体上，并评估共生菌株侧翼区域的缺失程度。在具体目标3中，将描述与COPD相关的潜在毒力基因在COPD菌株中的共存情况，并将使用分类树分析来确定每个基因对“COPD致病类型”的相对贡献。在特定的目标4中，将用酶联免疫吸附试验检测人上皮细胞对“COPD病毒型”流感嗜血杆菌的免疫介质的表达。项目相关性：该项目的结果将确定与COPD相关的流感嗜血杆菌基因，并将描述它们在刺激人类上皮细胞免疫反应方面的作用。这些结果将有助于更好地了解与COPD相关的流感嗜血杆菌毒力途径，并为COPD的预防和管理提供新的策略。(摘要结束)

DESCRIPTION (provided by applicant): PROJECT SUMMARY: Chronic obstructive pulmonary disease results from a complex interplay of environmental factors, host immune responses, and microbial factors. The bacterium Haemophilus influenzae colonizes the human respiratory tract and is an important pathogen associated with COPD. The overall goal of this study is to identify H. influenzae factors that contribute to the pathogenesis of COPD. The underlying principles exploited in this proposal are that H. influenzae are genetically highly variable and that natural selection preserves necessary genes among specific populations of bacteria. In Specific Aim 1 the prevalence of known H. influenzae virulence genes will be described among H. influenzae strains isolated from patients with COPD and from adults without COPD. In Specific Aim 2 additional genes that segregate differentially among H. influenzae isolated from patients with COPD and from adults without COPD will be identified. This gene discovery effort will utilize subtractive genomic hybridization to identify H. influenzae DNA fragments that correspond to genes present in a representative COPD H. influenzae strain but absent in a representative commensal strain. The prevalence of the resultant DNA fragments among COPD and non-COPD H. influenzae strains will be assessed using a bacterial genomic microarray technique. In addition, the corresponding genes of the COPD-associated DNA fragments will be defined and mapped on the H. influenzae chromosome, and the extent of the deletion in flanking regions of the commensal strain assessed. In Specific Aim 3, the co-occurrence of the potential COPD-associated virulence genes among COPD strains will be described and the relative contribution of each gene to the "COPD pathotype" will be determined using a classification tree analysis. In Specific Aim 4, the expression of immune mediators by human epithelial cells in response to H. influenzae of the "COPD pathotypes" will be measured using ELISA. PROJECT RELEVANCE: The results of this project will identify H. influenzae genes that are associated with COPD will describe their role in stimulating immune responses by human epithelial cells. These results will lead to a better understanding of the H. influenzae virulence pathways associated with COPD and lead to novel new strategies for prevention and management of COPD. (End of Abstract)