Outer Membrane Proteins of Pathogenic Oral Treponemes Inhibit Actin Rearrangement and Antimicrobial Functions of Neutrophils

牙周病是一种细菌引起的炎症性疾病，在美国有47 是全世界牙齿脱落的头号原因。这种情况的特点是破坏 牙齿支撑结构由宿主免疫系统和正常 口腔黏膜生物膜。齿垢密螺旋体、嗜麦芽寡养密螺旋体和溶卵磷脂密螺旋体是 三种未充分研究的细菌物种丰富的多微生物生物膜相关的严重牙周炎 疾病，并且缺乏对其致病特性的完整理解。T.牙齿，最好的- 研究的口腔螺旋体，有一个突出的毒力因子：主要的外鞘蛋白（Msp）， 使宿主细胞包括嗜中性粒细胞的功能失调。T. maltophilium和T.溶卵磷脂菌具有 Msp样外膜蛋白分别称为MspA和MspTL。中性粒细胞是先天免疫的关键 通过协调细胞信号，结构元件， 和细胞功能。MSP通过破坏磷酸肌醇和细胞脂质的平衡来抑制中性粒细胞的功能 代谢物是细胞内信号传导的关键。这种破坏涉及PI 3激酶（PI 3 K）的调节改变。 以及磷酸酶和张力蛋白同源物（PTEN）轴，导致肌动蛋白的不适当重塑 细胞骨架、趋化性受损和中性粒细胞功能改变。我们知识中的一个空白是 这些未充分研究的密螺旋体蛋白如何调节肌动蛋白动力学以损害其他重要的中性粒细胞 特性.该项目的总体目标是描述这些密螺旋体属物种及其 表面蛋白操纵中性粒细胞骨架信号通路和颗粒释放， 生存我们假设Msp样蛋白失调中性粒细胞肌动蛋白重塑，以促进细菌感染。 生存为了验证这一假设，本项目旨在（1）表征Msp蛋白对细胞增殖的影响。 PI 3 K/PTEN轴和肌动蛋白分支动力学和（2）评估密螺旋体物种及其Msp 通过调节中性粒细胞募集和脱粒来促进存活的蛋白质。为了实现这些目标，我 将利用各种方法，包括肌动蛋白掺入分析，免疫学技术， 显微术、流式细胞术、动物模型、分子生物学和微生物学技术。完成 该项目将为螺旋体和免疫系统之间的相互作用提供有价值的见解， 这些关系如何推动疾病进展。将在以下范围内执行的辅导和培训计划： 布法罗大学的多学科研究环境将为我提供科学和 成功过渡到成功研究的下一阶段所需的专业发展技能 事业

Periodontal disease is a bacterially induced inflammatory condition affecting 47% of adults in the United States and is the number one cause of tooth loss worldwide. This condition is characterized by the destruction of tooth-supporting structures resulting from dysbiosis between the host immune system and the normally commensal oral biofilm. Treponema denticola, Treponema maltophilium, and Treponema lecithinolyticum are three understudied bacterial species abundant in the polymicrobial biofilm associated with severe periodontal disease, and a complete understanding of their pathogenic properties is lacking. T. denticola, the most-well- studied oral spirochete, has a prominent virulence factor: the major outer sheath protein (Msp) that dysregulates the functions of host cells, including neutrophils. T. maltophilium and T. lecithinolyticum have Msp-like outer membrane proteins called MspA and MspTL, respectively. Neutrophils are key innate immune cells that protect oral tissues from pathogenic bacteria by coordinating cellular signaling, structural elements, and cell function. Msp inhibits neutrophil function by disrupting the balance of phosphoinositides, cellular lipid metabolites key for intracellular signaling. This disruption involves altered regulation of the PI3 kinase (PI3K) and phosphatase and tensin homolog (PTEN) axis, leading to inappropriate remodeling of the actin cytoskeleton, impaired chemotaxis, and altered functioning of neutrophils. A remaining gap in our knowledge is how these understudied Treponema proteins modulate actin dynamics to impair other crucial neutrophil properties. The overall objective of this project is to characterize how these Treponema species and their surface proteins manipulate neutrophil cytoskeleton signaling pathways and granule release to promote survival. We hypothesize that Msp-like proteins dysregulate actin remodeling in neutrophils to promote bacterial survival. To test this hypothesis, this project aims to (1) characterize the effects of Msp proteins on the PI3K/PTEN axis and actin branching dynamics and (2) assess the ability of Treponema species and their Msp proteins to promote survival by modulating neutrophil recruitment and degranulation. To achieve these aims, I will utilize a variety of methods, including analyses of actin incorporation, immunological techniques, microscopy, flow cytometry, animal models, molecular biology, and microbiological techniques. Completion of this project will provide valuable insight into the interactions between spirochetes and the immune system and how these relationships drive disease progression. The mentoring and training plan to be performed within the multidisciplinary research environment at the University at Buffalo will provide me with the scientific and professional development skills necessary to successfully transition to the next stage of a successful research career.