Microbial sphingolipids and suppression of host inflammation in periodontal disease

微生物鞘脂和牙周病宿主炎症的抑制

• 批准号: 10435569
• 负责人: Mary Ellen Davey
• 金额: $ 57.49万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10435569
• 关键词: Affect; Atmosphere; Bacteroides; Bacteroidetes; Biochemical; Cell Communication; Cell Culture Techniques; Cell membrane; Cells; Chemistry; Chronic; Clinical; Collaborations; Communication; Development; Disease; Elements; Genes; Genetic; Genetic Transcription; Gingiva; Goals; Growth; Health; Human; Immune; Immune response; Immunity; Immunologics; Immunosuppression; In Vitro; Infection; Inflammation; Inflammatory Response; Innate Immune Response; Knowledge; Lipids; Mediating; Membrane; Metabolism; Methodology; Methods; Microbe; Modeling; Molecular; Mucous Membrane; Mus; Nature; Oral; Oral cavity; Organism; Pathogenesis; Pathogenicity; Periodontal Diseases; Physiology; Play; Porphyromonas gingivalis; Prevention; Prokaryotic Cells; Proteins; Publications; Publishing; Research; Role; Signal Pathway; Signal Transduction; Signaling Molecule; Source; Sphingolipids; Surface; System; Techniques; Testing; Tissues; Tooth structure; Vesicle; Virulence; Vision; bone loss; cell motility; cytokine; defined contribution; immune function; immune imaging; immunoregulation; in vivo; inflammatory milieu; intestinal homeostasis; macrophage; member; microbial; microscopic imaging; mutant; neutrophil; novel; oral infection; oral pathogen; periodontopathogen; programs; response; subgingival microbiota; symbiont; targeted treatment; therapeutic development; trafficking; transcriptome sequencing; transcriptomics; treatment strategy

PROJECT SUMMARY Eukaryotic SLs are the basic building blocks of cell membranes and serve as key signaling molecules. Bacterial synthesis of SLs is poorly understood, and almost entirely restricted to the phylum Bacteroidetes. These microbes are generally considered symbionts of mammalian hosts. Although microbe-elicited chronic dysregulated inflammation is central feature of soft and hard tissue destruction and periodontal disease pathogenesis, this inflammation is, paradoxically, insufficient to clear the source of infection. Thus, subversion of host immunity is central to the chronic nature of this disease. Research has shown that Porphyromonas gingivalis, a member of the Bacteroidetes is uniquely capable of targeted and dynamic immune suppression, yet little is known of the underlying mechanisms. Remarkably, our studies have illuminated the importance of P. gingivalis SL in regulating the elicited host immune response to this organism and we have shown that these SLs are transferred from this organism and incorporated into host cells – putatively understood as an interkingdom communication system. The overarching hypothesis of the research we propose is that synthesis of SLs affords P. gingivalis and possibly other oral Bacteroidetes a mechanism of immune regulation. Specifically, our published and preliminary studies have determined that P. gingivalis secretes SL-containing outer membrane vesicles (OMVs) that elicit only mild inflammation compared to OMVs from a P. gingivalis mutant incapable of synthesizing SLs, and that the phosphoglycerol-dihydrocerimides (a subset of SLs) containing OMVs are particularly adept at immune suppression. We are proposing that SL-OMVs are an exquisite delivery system that forms the basis of a mechanism of P. gingivalis-host communication to control inflammation. The goal of our proposed studies is to determine how P. gingivalis SLs contribute to OMV cargo loading and subsequently how these SL-OMVs modulate the host innate inflammatory response. We will interrogate host sensing of P. gingivalis SL-OMVs both in vitro and in vivo. As early innate immune responses control host responses at mucosal surfaces such as the oral cavity, we will employ unique genetically modified P. gingivalis strains, and OMVs isolated from these strains to determine which OMV-components are involved in suppression. Molecular, immunologic, imaging, and transcriptomic, and biochemical techniques will be deployed to elucidate the underlying functions of SL-OMVs and mechanisms of host innate signaling. Lastly, we will use oral bone loss modelling to examine the virulence of P. gingivalis strains that are altered in the synthesis of SLs. The rationale for these studies is that identifying immunoregulatory mechanisms used by oral pathogens will provide prime targets for the development of therapeutic strategies. Thus, the long-term goal of this research program is to elucidate the mechanisms underlying SL-mediated OMV delivered immune suppression and to determine if bacterial SL-synthesis can be targeted for treatment and prevention of periodontal disease.

项目总结 真核细胞中的SLS是细胞膜的基本组成成分，是关键的信号分子。 细菌对SLS的合成知之甚少，几乎完全局限于拟杆菌门。 这些微生物通常被认为是哺乳动物宿主的共生体。虽然由微生物引起的慢性 炎症调节失调是软硬组织破坏和牙周病的主要特征 自相矛盾的是，在发病机制上，这种炎症不足以清除感染源。因此，颠覆 宿主免疫力的变化是这种疾病慢性本质的核心。研究表明，卟啉单胞菌 牙龈杆菌是拟杆菌属中的一员，具有独特的靶向和动态免疫抑制能力， 然而，人们对其潜在机制知之甚少。值得注意的是，我们的研究已经阐明了 牙龈假单胞菌在调节诱导宿主对这种生物的免疫反应中的作用，我们已经证明 这些SLS从这种有机体转移到宿主细胞中--据推测是一种 跨王国通信系统。我们提出的这项研究的首要假设是 SLS的作用为牙龈假单胞菌和可能的其他口服类杆菌提供了一种免疫调节机制。 具体地说，我们已发表的和初步的研究已经确定牙龈假单胞菌分泌含有SL的 仅引起轻微炎症的外膜小泡(OMV)，与牙龈假单胞菌的OMV相比 不能合成SLS的突变体，以及磷酸甘油-二氢亚胺(SLS的一个子集) 含有OMV的病毒特别擅长免疫抑制。我们建议SL-OMV是一种 精巧的输送系统，构成了牙龈假单胞菌-宿主通信控制机制的基础 发炎。我们提议的研究的目标是确定牙龈假单胞菌SLS对OMV货物的贡献。 加载以及随后这些SL-OMV如何调节宿主固有的炎症反应。我们会 在体外和体内询问牙龈假单胞菌的寄主感觉。作为早期的先天免疫反应 为了控制口腔等粘膜表面的宿主反应，我们将使用独特的转基因 以及从这些菌株中分离出的OMV，以确定哪些OMV组分参与其中 在压制中。分子、免疫学、成像、转录和生化技术将被 用来阐明SL-OMV的潜在功能和宿主固有信号的机制。最后， 我们将使用口腔骨质流失模型来检测牙龈假单胞菌菌株的毒力，这些菌株在 SLS的合成。这些研究的基本原理是，确定由 口腔病原体将为治疗策略的发展提供主要靶点。因此，从长远来看， 本研究的目的是阐明SL介导的OMV递送免疫的机制 抑制和确定细菌SL合成是否可以靶向治疗和预防 牙周病。