Mycoplasma pneumoniae activation of airway epithelium

肺炎支原体激活气道上皮

• 批准号: 7256810
• 负责人: Jerry W Simecka
• 金额: $ 7.2万
• 依托单位: UNIVERSITY OF NORTH TEXAS HLTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7256810
• 关键词: Address; Adhesions; Asthma; Bacteria; Bacterial Adhesins; Blocking Antibodies; Cell Adhesion Molecules; Cell Line; Cell membrane; Cells; Chronic; Complement; Development; Disease; Epithelial Cells; Epithelium; Event; Experimental Designs; Foundations; Future; Generations; Health; Histologic; Human; Immune; Immune response; Infection; Inflammatory; Inflammatory Response; Lead; Lesion; Life; Lipoproteins; Lung; Lung diseases; Lymphocyte; Mediating; Membrane; Messenger RNA; Molecular; Monitor; Mycoplasma; Mycoplasma pneumoniae; Organism; Pathogenesis; Patients; Plasmids; Pneumonia; Production; Proteins; Recovery; Research; Respiratory System; Role; Severities; Submucosa; Symptoms; Testing; Thinking; Toll-like receptors; Transfection; United States; Walking; airway epithelium; chemokine; cytokine; novel; novel strategies; pathogen; prevent; respiratory; response

DESCRIPTION (provided by applicant): Mycoplasma pneumoniae is a major cause of lung disease in humans, and the initial interaction with airway epithelial cells is likely to contribute to subsequent disease development. It is clear that immune responses against mycoplasma are a major component of disease with the recruitment and development of immune-mediated inflammatory responses in the submucosa of the respiratory tract. Thus, the factors produced by airway epithelial cells are likely to influence the pathogenesis of these immune-mediated lesions; however, the full complement of cytokines/chemokines produced by airway epithelial cells is unknown. Furthermore, the mechanisms and mycoplasma components involved in the activation of these cells is uncharacterized. If understood, this information could facilitate the development of new approaches to intervene in mycoplasma and other pulmonary diseases. The long-term objective of this project is to determine the molecular mechanisms central to the generation of immune responses in mycoplasma respiratory disease. This project proposes to test the hypothesis that M. pneumoniae stimulate human respiratory bronchoepithelial cells to produce chemokines or other cytokines that are likely to contribute to the inflammatory lesions. Furthermore, we propose that mycoplasma adhesion protein promote the interaction between mycoplasma lipoproteins and toll-like receptors (TLR) of respiratory epithelial cells, which in turn stimulate the production these factors by epithelial cells. Specifically, we proposed to address the following questions: 1) Do M. pneumoniae membrane components activate or damage human bronchoepithelial cells and is this dependent on adhesion molecules? 2) Does M. pneumoniae stimulate human bronchoepithelial cells via toll-like receptors (TLR)? The experimental designs are: 1) Viable mycoplasma, mycoplasma membranes and lipoproteins will stimulate a human bronchoepithelial cell line. Cytokine/chemokine mRNA and protein levels will be determined. We will compare the activity of an adherent parental mycoplasma strain with a nonadherent strain. 2) The expression of TLR by bronchoepithelial cells will be monitored before and after mycoplasma stimulation. Cell lines lacking TLR will be transfected with plasmids expressing each of the human TLR to determine their roles in mycoplasma (cell, membranes and lipoproteins) stimulation of cells. The role of the TLR on human bronchoepithelial cells will be determined using blocking antibodies or transfection with inactive forms of TLR. These studies will provide the foundation for future studies to further elucidate the molecular events involved in these responses, and examine the role of epithelium-derived chemokines/cytokines in disease pathogenesis. Furthermore, it is likely that these events contribute to the exacerbation of asthma and other respiratory diseases. Thus, modulation of each of these events may lead to novel therapies against mycoplasma and other chronic respiratory diseases. The bacterium, Mycoplasma pneumoniae, is responsible for "walking pneumonia" which comprises at least 30% of the pneumonia cases in the United States and associated with severe asthma. The proposed research will study the mechanism through which this bacterium causes lung disease and more severe asthma. Ultimately, we expect these studies will lead to more effective treatments of diseases due to this bacterium by means of promoting favorable, rather than harmful, responses within the lungs of patients.

描述（由申请人提供）：肺炎支原体是人类肺部疾病的主要原因，最初与气道上皮细胞的相互作用可能会导致随后的疾病发展。很明显，针对支原体的免疫反应是疾病的主要组成部分，因为呼吸道粘膜下层中免疫介导的炎症反应的募集和发展。因此，气道上皮细胞产生的因子很可能影响这些免疫介导病变的发病机制。然而，气道上皮细胞产生的全部细胞因子/趋化因子尚不清楚。此外，参与这些细胞激活的机制和支原体成分尚不清楚。如果理解这些信息，将有助于开发干预支原体和其他肺部疾病的新方法。该项目的长期目标是确定支原体呼吸道疾病中产生免疫反应的核心分子机制。该项目旨在检验肺炎支原体刺激人呼吸道支气管上皮细胞产生趋化因子或其他可能导致炎症病变的细胞因子的假设。此外，我们提出支原体粘附蛋白促进支原体脂蛋白与呼吸道上皮细胞的Toll样受体（TLR）之间的相互作用，进而刺激上皮细胞产生这些因子。具体来说，我们建议解决以下问题：1）肺炎支原体膜成分是否激活或损伤人支气管上皮细胞，这是否依赖于粘附分子？ 2) 肺炎支原体是否通过Toll样受体（TLR）刺激人支气管上皮细胞？实验设计是：1)活支原体、支原体膜和脂蛋白将刺激人支气管上皮细胞系。将测定细胞因子/趋化因子 mRNA 和蛋白质水平。我们将比较贴壁亲代支原体菌株与非贴壁菌株的活性。 2)在支原体刺激前后监测支气管上皮细胞TLR的表达。缺乏 TLR 的细胞系将用表达每种人类 TLR 的质粒转染，以确定它们在支原体（细胞、细胞膜和脂蛋白）刺激细胞中的作用。 TLR 对人支气管上皮细胞的作用将通过使用封闭抗体或用非活性形式的 TLR 转染来确定。这些研究将为未来的研究奠定基础，以进一步阐明这些反应中涉及的分子事件，并检查上皮衍生的趋化因子/细胞因子在疾病发病机制中的作用。此外，这些事件可能会导致哮喘和其他呼吸道疾病的恶化。因此，调节这些事件中的每一个可能会导致针对支原体和其他慢性呼吸道疾病的新疗法。肺炎支原体细菌是“行走性肺炎”的罪魁祸首，这种肺炎占美国肺炎病例的至少 30%，并与严重哮喘有关。拟议的研究将研究这种细菌导致肺部疾病和更严重的哮喘的机制。最终，我们预计这些研究将通过促进患者肺部的有利反应而不是有害反应，从而更有效地治疗这种细菌引起的疾病。