Interaction of Treponema denticola virulence factors with neutrophils to modulate polymicrobial responses

项目总结/摘要 牙周病以某种形式影响高达47%的成年人口，并与许多严重的疾病有关。 系统性疾病。尽管牙周病的健康和经济负担很大， 对口腔中的微生态细菌群落和免疫反应的影响尚不清楚。 齿垢密螺旋体、口腔坦那氏菌和牙龈卟啉单胞菌沿着构成“红色 牙周病是一种常见的牙周病。主要外鞘蛋白 (Msp)中医已知齿垢会使宿主细胞包括嗜中性粒细胞的功能失调。中性粒细胞是关键 细胞的身体的先天防御线对病原体在牙龈组织，但在牙周 疾病，使其无效。磷酸肌醇（PIP），重要的细胞脂质的调节 代谢物，通过适当的脂质激酶和磷酸酶活性是至关重要的协调中性粒细胞 功能和驱动免疫反应。Msp通过抑制PI 3 K和PI 3 K受体而破坏细胞PIP平衡。 磷酸酶和张力蛋白同源物（PTEN）的活化。尽管他是T。齿垢最突出的 毒力因子，Msp的能力，限制中性粒细胞趋化性背后的确切机制，通过操纵 PI 3 K/PTEN脂质代谢途径尚不清楚。我们假设，暴露于Msp，在孤立 形成或作为外膜囊泡的组成部分，将限制中性粒细胞对T。牙齿，但 也是次要的“红色复合物”的其他成员，促进细菌的相互作用和生存的 口腔中的微生物生物膜。本项目的总体目标是描述T.齿垢密 损害中性粒细胞功能，作为先天免疫应答失调的手段，目的是鉴定 Msp干扰PI 3 K信号传导和磷酸酶激活的机制，并表征Msp如何干扰PI 3 K信号传导和磷酸酶激活。 Msp与嗜中性粒细胞的相互作用支持严重牙周病的微生态环境。 这些目标将通过1）确定Msp在激活脂质磷酸酶SHIP 1中的作用来实现 以及Msp如何与脂质激酶PI 3 K的不同亚型相互作用以改变正常的中性粒细胞信号传导 反应和2）表征T.齿垢和Msp与中性粒细胞的相互作用， 中性粒细胞对其他病原体的反应能力。这项工作将填补在致病性知识的空白 中医齿垢及其在多微生物感染中驱动嗜中性粒细胞反应的作用。 此外，本提案中概述的辅导和培训计划将有助于实现 在未来发展成功的独立学术研究计划所需的专业技能。

Project Summary/Abstract Periodontal disease affects up to 47% of the adult population in some form and is linked to a number of serious systemic diseases. Despite the significant health and economic burden of periodontal disease, much remains unknown about the effect of the dysbiotic bacterial community and immune response in the oral cavity. Treponema denticola, along with Tannerella forsythia and Porphyromonas gingivalis, compose the “red complex” of bacteria, prominently associated with severe periodontal disease. The major outer sheath protein (Msp) of T. denticola is known to dysregulate functions of host cells, including neutrophils. Neutrophils are key cells of the body's innate line of defense against pathogens in the gingival tissue, yet during periodontal disease, they are rendered ineffective. Regulation of phosphoinositides (PIPs), important cellular lipid metabolites, through appropriate lipid kinase and phosphatase activity are crucial to orchestrating neutrophil function and driving the immune response. Msp upsets the cellular PIP balance through inhibition of PI3K and activation of the phosphatase and tensin homolog (PTEN). Despite being one of T. denticola's most prominent virulence factors, the exact mechanism behind Msp's ability to limit neutrophil chemotaxis by manipulating the PI3K/PTEN lipid metabolism pathway is not well understood. We hypothesize that exposure to Msp, in isolated form or as a component of outer membrane vesicles, will limit neutrophils from responding to T. denticola, but also secondarily to other members of the “red complex”, promoting bacterial interaction and survival of the polymicrobial biofilm in the oral cavity. The overall objective of this project is to characterize how T. denticola impairs neutrophil function as a means to dysregulate the innate immune response, with the goal to identify the mechanism by which Msp interferes with PI3K signaling and phosphatase activation and characterize how the interaction of Msp with neutrophils supports the dysbiotic bacterial environment of severe periodontal disease. These goals will be accomplished by 1) determining the role of Msp in activating the lipid phosphatase SHIP1 and how Msp interacts with different isoforms of the lipid kinase PI3K to alter normal neutrophil signaling response and 2) characterizing the impact of T. denticola and Msp interaction with neutrophils to alter the ability of neutrophils to respond to other pathogens. This work will fill a gap in knowledge of the pathogenicity of T. denticola and its role in driving the manipulation of the neutrophil response in polymicrobial infections. Furthermore, the mentoring and training plan outlined in this proposal will aid in the attainment of the professional skills necessary to develop a successful independent academic research program in the future.