The Structure and Function of Dental Lymphatics (R21)

牙齿淋巴管的结构和功能（R21）

• 批准号: 10388309
• 负责人: PHILIP D KING
• 金额: $ 23.4万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-08 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10388309
• 关键词: 3-Dimensional; Address; Animal Model; Antigen-Presenting Cells; Antigens; Apical; Biological Assay; Biology; Blood; Blood Circulation; Blood Vessels; Blood capillaries; Caliber; Cardiovascular system; Cell Death; Cells; Cessation of life; Clinical; Consensus; Data; Dental; Dental Pulp; Dental Research; Drainage procedure; Endodontics; Floor; Fluid Balance; Fusobacterium nucleatum; Future; Host Defense; Hour; Image; Immune; Immune response; Immunity; Immunology; In Vitro; Infection; Inflammatory; Intercellular Fluid; Knowledge; Lead; Life; Link; Liquid substance; Lymphatic; Lymphatic Endothelial Cells; Lymphatic System; Lymphatic function; Mediating; Methods; Minerals; Mission; Modeling; Mus; Organ; Outcome; Peripheral; Plant Roots; Play; Polymer Chemistry; Positioning Attribute; Prevention therapy; Public Health; Pulp Canals; Pulp Chambers; Regulation; Research; Role; Science; Site; Structure; System; Testing; Time; Tissues; Tooth structure; Travel; United States National Institutes of Health; adaptive immune response; adaptive immunity; body system; burden of illness; dental infection; dental structure; disability; draining lymph node; follow-up; improved; innovation; lymph nodes; lymphatic vessel; macrophage; man; mouse model; multidisciplinary; novel; novel strategies; novel therapeutics; particle; pathogen; promoter; response; three dimensional structure; tool; two photon microscopy; two-photon; uptake

The lymphatic vessel (LV) system is a parallel circulatory system to the blood circulatory system present in almost all tissues. One major function of the LV system is the return of extravasated interstitial fluid to the blood vessel (BV) circulation. In addition, LV act as conduits for the traffic of antigens and antigen-presenting cells from peripheral tissue sites to draining lymph nodes, thereby permitting the induction of adaptive immunity. The existence of LV in dental pulp is still a controversial issue; no consensus as to whether LV are present in the dental pulp has hitherto been reached. In addition, even in those studies that support the existence of dental LV, the overall organization of the dental LV system and its three-dimensional (3D) structure has not been demonstrated. Furthermore, whether a putative dental LV system is involved in immune-inflammatory regulation, similar to the role of LV in other organ systems, is an important question that has not been addressed. We have recently identified a 3D network of LV in dental pulp using a Prox1-eGFP mouse model in which the Prox1 promoter drives expression of eGFP specifically in lymphatic endothelial cells (LEC). As imaged by Two-photon microscopy, the network comprises of microcapillaries (≃3-5 um in diameter) that form dense plex- uses mainly in the pulp chamber and which connect to larger vessels (≃10-15 um in diameter) that travel as a bundle from the pulp chamber floor through the root canals. In addition, we found that infection of dental pulp with Fusobacterium nucleatum resulted in disappearance of coronal microcapillary LV plexuses within 48 hours, suggesting that pulpal infection induces rapid death of LEC in the dental pulp. The structural and functional relationship of components of the identified dental LV network to each other and to the different types of LV that have been identified in other organs is unknown. In addition, the mechanism of infection-induced LV loss has not been determined. Answers to these questions are expected to inform upon the role of dental LV in host immunity to dental pathogens. In this proposal, the assembled multidisciplinary team will further investigate the structure, function, and pathophysiological changes of the dental pulp LV network using an innovative animal model, two-photon micros- copy, a dental infection model, and a fluorescent particle-tracking assay to confirm that the identified LV network conveys pulpal material to draining lymph nodes. There are two specific aims as follows: Aim 1. To characterize normal lymphatics in mouse dental pulp Aim 2. To examine the response of dental pulp lymphatics to pulpal infection Successful completion of the proposed aims will significantly advance our understanding of LV biology, pulp biology, and the immune response to dental infection and is expected to lead to follow-up projects that focus upon host pathogen relationships in the dental pulp.

淋巴管（LV）系统是与血液循环系统平行的循环系统 左心室系统的一项主要功能是将渗出的间质液返回到几乎所有组织中。 此外，LV 还充当抗原运输和抗原呈递的管道。 细胞从外周组织部位转移到引流淋巴结，从而诱导适应性免疫。 牙髓中是否存在 LV 仍然是一个有争议的问题；对于 LV 是否存在尚无共识。 迄今为止，即使在那些支持存在的研究中也已达到。 牙科 LV，牙科 LV 系统的整体组织及其三维 (3D) 结构尚未确定 此外，假定的牙科 LV 系统是否参与免疫炎症调节， 与 LV 在其他器官系统中的作用类似，这是一个尚未得到解决的重要问题。 我们最近使用 Prox1-eGFP 小鼠模型识别了牙髓中 LV 的 3D 网络，其中 Prox1 启动子在淋巴内皮细胞 (LEC) 中特异性驱动 eGFP 表达。 双光子显微镜，网络由形成致密丛的微毛细管（直径≃3-5微米）组成 主要用于牙髓腔并连接到较大的血管（直径≃10-15 um），这些血管作为 另外，我们还发现牙髓的感染。 具核梭杆菌导致冠状微毛细血管左心室丛在 48 小时内消失， 提示牙髓感染会导致牙髓中 LEC 快速死亡。 已识别的牙科 LV 网络各组成部分之间的结构和功能关系 此外，对于其他器官中已发现的不同类型的 LV，其机制尚不清楚。 感染引起的 LV 损失尚未确定，这些问题的答案预计将在稍后公布。 牙科 LV 在宿主对牙科病原体免疫中的作用。 在本提案中，组建的多学科团队将进一步研究结构、功能和 使用创新动物模型双光子显微技术观察牙髓 LV 网络的病理生理变化 副本、牙齿感染模型和荧光粒子追踪测定，以确认已识别的 LV 网络 将牙髓物质输送至引流淋巴结有两个具体目标： 目标 1. 表征小鼠牙髓中的正常淋巴管 目标 2. 检查牙髓淋巴管对牙髓感染的反应 成功完成拟议目标将显着增进我们对慢病毒生物学的理解， 牙髓生物学和对牙齿感染的免疫反应，预计将导致后续项目重点关注 牙髓上宿主病原体的关系。