Tobacco-induced alterations to P. gingivalis-host interactions

烟草引起的牙龈卟啉单胞菌与宿主相互作用的改变

• 批准号: 8270372
• 负责人: David A Scott
• 金额: $ 37.13万
• 依托单位: UNIVERSITY OF LOUISVILLE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-15 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8270372
• 关键词: Anabolism; Antibodies; Antigens; Area; Back; Bacteria; Bacterial Proteins; Cells; Cellular Structures; Characteristics; Chronic; Chronic Obstructive Airway Disease; Clinical; Communicable Diseases; Conditioned Culture Media; Coronary Arteriosclerosis; Cytokine Suppression; Data; Dental; Diabetes Mellitus; Disease; Economic Burden; Exhibits; Exposure to; Foundations; Future; Gene Expression; Gene Expression Profile; Gene Expression Regulation; Genes; Genome; Genomics; Goals; Gram-Negative Anaerobic Bacteria; Health Care Costs; Human; IS Elements; Immune; Immune response; Immune system; In Vitro; Inflammation; Inflammatory; Inflammatory Response; Investigation; Lipid A; Lung diseases; Membrane; Membrane Proteins; Microarray Analysis; Microbial Biofilms; Modeling; Molecular; Operon; Organism; Pathogenesis; Patients; Periodontitis; Persons; Phenotype; Physiological; Play; Pneumonia; Polysaccharides; Population; Porphyromonas gingivalis; Predisposition; Proteins; Refractory; Relative (related person); Reporter Genes; Risk; Rodent Model; Role; Severities; Smoke; Smoker; Smoking; Specificity; Stress; Stroke; Structure; Surface; Systemic disease; TNF gene; Testing; Tissues; Tobacco; Tobacco smoke; Tooth structure; Transcript; Transposase; United States; Vascular Diseases; Virulence; capsule; cigarette smoke-induced; cigarette smoking; fimbria; in vivo; insight; microbial; monocyte; neutrophil; non-smoker; novel; pathogen; public health relevance; response; tobacco exposure; trait

DESCRIPTION (provided by applicant): Periodontitis is a destructive, infectious disease that has been associated with multiple fatal and debilitating chronic systemic diseases and consumes billions of dollars in health costs annually in the US. Tobacco smokers exhibit increased susceptibility to periodontitis; are more likely to be infected with the key periodontal pathogen Porphyromonas gingivalis; and to harbor higher numbers of this bacterial species relative to non-smokers. Despite this, smokers consistently exhibit reduced clinical inflammation. We show that the pro-inflammatory response of purified human monocytes is significantly suppressed when P. gingivalis is exposed to cigarette smoke extracts (CSE) and that the inflammation inducing potential of P. gingivalis is restored when cells are sub-cultured back into fresh medium without CSE. However, the influence of tobacco on the regulation of genes encoding P. gingivalis virulence determinants is essentially unknown. We hypothesize that CSE represents an environmental stress and that P. gingivalis responds by altering gene expression to adapt to this stress. We believe that this adaptive response may involve the induction of stress-related genes, virulence determinants and alterations of bacterial surface components. We also hypothesize that such cigarette smoke-induced physiological changes in P. gingivalis will include altered activities of genes encoding key pathogen recognition determinants, which will explain the reduced inflammatory response of smoke-exposed P. gingivalis. It is our aim to identify, isolate and test CSE-altered gene products in a primary human monocyte model of inflammation. Preliminary data generated through transcriptome analyses and the structural characterization of several microbial determinants are strongly supportive of our hypotheses. We have identified several genes, gene products, and bacterial structures that are dysregulated on CSE exposure that may play pivotal roles in the engagement of the innate immune system by P. gingivalis. These include fimbrial proteins, LPS, major outer membrane antigens, and other P. gingivalis components of known inflammatory potential, such as dnaJ, grpE and ragA. These studies represent a novel area of investigation and will provide some of the first information illustrating how P. gingivalis responds at the molecular level to cigarette smoke and may provide unique insights into disease pathogenesis in smokers. Thus, these studies will break new ground and provide the foundation for future studies that will elucidate mechanisms explaining how tobacco influences pathogen-host response interactions. PUBLIC HEALTH RELEVANCE: The Gram negative anaerobic bacterium, Porphyromonas gingivalis, is a causative agent of chronic periodontitis, a destructive tobacco-induced and/or exacerbated disease. Smokers are more likely to be infected by P. gingivalis and to harbor higher numbers of these bacterial cells than non-smokers. However, smokers also exhibit reduced clinical inflammation and, in keeping with this, smoke-exposed P. gingivalis exhibits a reduced capacity to illicit an inflammatory response from immune cells. The mechanisms underlying this reduced inflammatory potential are entirely unknown. Therefore, we will identify P. gingivalis genes that are dysregulated by tobacco exposure by microarray analysis of P. gingivalis cultured in cigarette smoke extract (CSE)-conditioned medium. We will also examine the effects of CSE on the characteristics of cellular structures known to play critical roles in the activation of innate immune cells, such as LPS and fimbriae. The inflammatory potential of tobacco-altered bacterial structures and the products of CSE-dysregulated genes will be tested in freshly isolated human monocytes. This study will provide some of the first information illustrating how P. gingivalis responds at the molecular level to cigarette smoke and may provide unique insights into disease pathogenesis in smokers.

描述（由申请人提供）：牙周炎是一种破坏性传染病，与多种致命和衰弱的慢性全身性疾病有关，每年在美国消耗数十亿美元的健康费用。吸烟者对牙周炎的易感性增加；更有可能感染牙周关键病原体牙龈卟啉单胞菌；相对于不吸烟者来说，这种细菌的数量更多。尽管如此，吸烟者始终表现出临床炎症减少。我们发现，当牙龈卟啉单胞菌暴露于香烟烟雾提取物（CSE）时，纯化的人单核细胞的促炎反应被显着抑制，并且当细胞传代培养回新鲜培养基中时，牙龈卟啉单胞菌的炎症诱导潜力得到恢复没有全面性教育。然而，烟草对牙龈卟啉单胞菌毒力决定簇编码基因的影响基本上是未知的。 我们假设 CSE 代表一种环境应激，牙龈卟啉单胞菌通过改变基因表达来适应这种应激。我们认为，这种适应性反应可能涉及应激相关基因的诱导、毒力决定因素和细菌表面成分的改变。我们还假设，香烟烟雾引起的牙龈卟啉单胞菌生理变化将包括编码关键病原体识别决定因素的基因活性改变，这将解释暴露于烟雾的牙龈卟啉单胞菌炎症反应的减少。我们的目标是在原代人类单核细胞炎症模型中鉴定、分离和测试 CSE 改变的基因产物。 通过转录组分析和几个微生物决定因素的结构表征产生的初步数据强烈支持我们的假设。我们已经确定了一些在暴露于 CSE 时失调的基因、基因产物和细菌结构，这些基因、基因产物和细菌结构可能在牙龈卟啉单胞菌参与先天免疫系统中发挥关键作用。这些包括菌毛蛋白、LPS、主要外膜抗原和其他已知具有炎症潜力的牙龈卟啉单胞菌成分，例如 dnaJ、grpE 和 ragA。 这些研究代表了一个新的研究领域，并将提供一些初步信息，说明牙龈卟啉单胞菌如何在分子水平上对香烟烟雾做出反应，并可能为吸烟者的疾病发病机制提供独特的见解。因此，这些研究将开辟新天地，并为未来的研究奠定基础，阐明烟草如何影响病原体-宿主反应相互作用的机制。 公共卫生相关性：革兰氏阴性厌氧菌牙龈卟啉单胞菌是慢性牙周炎的病原体，慢性牙周炎是一种破坏性的烟草诱发和/或加剧的疾病。吸烟者比不吸烟者更容易感染牙龈卟啉单胞菌，并且携带更多数量的这些细菌细胞。然而，吸烟者也表现出临床炎症减少，与此相一致，暴露于烟雾的牙龈卟啉单胞菌表现出引起免疫细胞非法炎症反应的能力降低。这种潜在炎症减少的机制尚不清楚。因此，我们将通过对在香烟烟雾提取物（CSE）条件培养基中培养的牙龈卟啉单胞菌进行微阵列分析来鉴定因烟草暴露而失调的牙龈卟啉单胞菌基因。我们还将研究 CSE 对已知在先天免疫细胞（如 LPS 和菌毛）激活中发挥关键作用的细胞结构特征的影响。烟草改变的细菌结构和 CSE 失调基因产物的炎症潜力将在新鲜分离的人单核细胞中进行测试。这项研究将提供一些初步信息，说明牙龈卟啉单胞菌如何在分子水平上对香烟烟雾作出反应，并可能为吸烟者的疾病发病机制提供独特的见解。