Modulation of innate epithelial cell responses by oral commensal bacteria

口腔共生细菌调节先天上皮细胞反应

• 批准号: 8967461
• 负责人: Octavio Alberto Gonzalez
• 金额: $ 11.29万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-07-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8967461
• 关键词: Address; Adverse effects; Affect; Bacteria; Birth; CCL20 gene; CXC Chemokines; Cell Culture Techniques; Cell Extracts; Characteristics; Development; Disease; Dose; Ecology; Environment; Epithelial; Epithelial Cells; Equilibrium; Evaluation; Foundations; Fusobacterium nucleatum; Future; Gene Targeting; Genes; Genetic Transcription; Goals; Health; Homeostasis; IL8 gene; Immune response; Inflammation; Inflammatory; Inflammatory Response; Investigation; Knowledge; Laboratories; Lead; Mediating; Messenger RNA; MicroRNAs; Molecular; Molecular Target; Mucous Membrane; Oral; Oral mucous membrane structure; Outcome; Pathologic; Pattern; Periodontal Diseases; Periodontitis; Porphyromonas gingivalis; Production; Protein Analysis; Proteins; Public Health; Regulation; Research; Research Design; Role; Streptococcus gordonii; Surface; Symbiosis; Taxon; Testing; Tissues; Transcriptional Activation; Translating; Translations; Up-Regulation; Work; arm; beta-Chemokines; chemokine; combat; commensal microbes; cytokine; design; evidence base; immunopathology; innovation; microbial; oral bacteria; oral commensal; oral pathogen; pathogen; pathogenic bacteria; periopathogen; prevent; public health relevance; response

 DESCRIPTION (provided by applicant): The mechanisms through which a persistent recognition of oral commensal bacteria by oral epithelial cells (OECs) mitigates an uncontrolled inflammatory response of the oral mucosa remain unknown. Evidence suggests that epithelial cells may discriminate between commensals and pathogenic bacteria through differential activation of responses, particularly cytokine/chemokine patterns, which ultimately influence both innate and adaptive arms of the immune response. Recent work in our laboratory has been identifying patterns of OECs responses following challenge with commensal and pathogenic oral bacteria. The results showed a significantly more robust (quality and quantity) chemokine transcriptional activity in response to the oral commensal S. gordonii (Sg) compared to the outcomes following challenge with the oral pathogens F. nucleatum (Fn) and P. gingivalis. Subsequent protein analysis of selected chemokines showed that there was a clear disconnect between the Sg-induced chemokine transcriptional activation and the reduced and limited protein levels found in OEC extracts and supernatants in comparison with the effect of Fn, which despite inducing lower mRNA chemokines levels (2 to 4-fold less), enhanced a robust protein chemokine production as previously shown. Therefore, we hypothesized that Sg and perhaps other oral commensal bacterial species have the ability to efficiently activate regulatory mechanisms for chemokine transcription and translation in order to minimize pathological inflammatory responses driven by OECs in mucosal tissues. Consistently, preliminary analysis showed that Sg has the ability to significantly up-regulate (>2- fold) the expression of 115/2578 miRNAs in OECs, whereby miR-663a, miR-4516, miR492, and miR193a-5p have validated gene targets involved in TLR- and cytokine-induced chemokine transcription and translation. To test this hypothesis we propose the following two specific aims: (i) To determine the chemokine transcriptional and translational responses of OECs to oral commensal bacteria, and (ii) To determine the role of specific miRNAs in regulating the chemokine production induced by oral commensal bacteria in OECs. To address these knowledge gaps, we will use OEC cultures to: (a) determine whether the disconnect between transcription and translation of chemokines in OECs is common feature of oral commensal bacterial species, and (b) determine the effect of oral commensals on the expression of specific miRNAs as regulators of these inflammatory molecules. The contribution of this investigation is expected to be the identification of the activ regulation of inflammatory responses in OECs by specific miRNAs as a potential "tolerogenic mechanism" by which oral commensal bacteria maintain symbiosis with the host. Importantly, diminutions of miRNAs that would be activated specifically by oral commensal bacteria (e.g., during dysbiosis) could be related to pathologic inflammatory changes observed in disease. This project's significance will enable a better understanding of the cellular and molecular mechanisms involved in the "tipping point" between epithelial tolerogenic and pathologic responses to oral bacteria. The results are expected to contribute to a strong evidence-based foundation for future studies designed to target these mechanisms and identify new molecular target(s) associated with oral bacteria-regulated epithelial chemokine production, and will ultimately provide new opportunities for the development of innovative approaches to prevent/treat periodontitis.

 描述（由申请人提供）：口腔上皮细胞（OEC）对口腔共生细菌的持续识别减轻口腔粘膜不受控制的炎症反应的机制仍然未知。有证据表明，上皮细胞可能通过反应的差异激活来区分共生菌和病原菌，特别是细胞因子/趋化因子模式，最终影响免疫反应的先天性和适应性。我们实验室最近的工作是确定 OEC 在受到共生和致病性口腔细菌挑战后的反应模式。结果显示，与口腔病原体具核梭菌 (Fn) 和牙龈卟啉单胞菌攻击后的结果相比，口腔共生戈登沙门氏菌 (Sg) 的趋化因子转录活性明显更强（质量和数量）。随后对所选趋化因子的蛋白质分析表明，与 Fn 的作用相比，Sg 诱导的趋化因子转录激活与 OEC 提取物和上清液中发现的降低和有限的蛋白质水平之间存在明显的脱节，尽管 Fn 诱导较低的 mRNA 趋化因子水平（减少 2 至 4 倍），但如先前所示，增强了强大的蛋白质趋化因子产生。因此，我们假设 Sg 和其他口腔共生细菌物种能够有效激活趋化因子转录和翻译的调节机制，以最大限度地减少粘膜组织中 OEC 驱动的病理炎症反应。初步分析一致表明，Sg 能够显着上调（>2 倍）OEC 中 115/2578 miRNA 的表达，其中 miR-663a、miR-4516、miR492 和 miR193a-5p 已验证参与 TLR 和细胞因子诱导的趋化因子转录和翻译的基因靶标。为了检验这一假设，我们提出以下两个具体目标：（i）确定 OEC 对口腔共生细菌的趋化因子转录和翻译反应，以及（ii）确定特定 miRNA 在调节 OEC 中口腔共生细菌诱导的趋化因子产生中的作用。为了解决这些知识差距，我们将使用 OEC 培养物来：（a）确定 OEC 中趋化因子转录和翻译之间的脱节是否是口腔共生细菌物种的共同特征，以及（b）确定口腔共生菌对作为这些炎症分子调节剂的特定 miRNA 表达的影响。这项研究的贡献预计将是确定特定 miRNA 对 OEC 炎症反应的主动调节，作为口腔共生细菌与宿主维持共生的潜在“耐受机制”。重要的是，由口腔共生细菌（例如，在菌群失调期间）特异性激活的 miRNA 的减少可能与疾病中观察到的病理炎症变化有关。该项目的意义在于更好地理解口腔细菌上皮耐受性和病理反应之间“临界点”所涉及的细胞和分子机制。预计这些结果将为未来的研究奠定坚实的循证基础，旨在针对这些机制并确定与口腔细菌调节的上皮趋化因子产生相关的新分子靶标，并最终为开发预防/治疗牙周炎的创新方法提供新的机会。