In vitro models of subgingival communities and their in vivo pathogenic potential

描述（由申请人提供）：牙周炎是牙齿支撑结构的一种炎症性疾病，由病原性龈下群落与宿主的相互作用引起。这种疾病的病理生理学尚未完全了解，因此新的预防或治疗策略的发展仍然难以捉摸。微生物群落是一个复杂的动态实体，其中微生物相互作用，因此表现出不同于单个物种的表型特征。此外，群落环境改变了微生物的致病潜力，这不仅是通过它们与宿主组织的直接相互作用实现的，而且间接地通过调节整个群落的行为来实现。因此，了解牙周炎的病因需要考虑微生物群落作为感染的挑战，而不是专注于单一物种作为病原体。目前还没有能够近似描述龈下环境中微生物的分类复杂性、环境条件和生长速率的群落模型。这种模型是必要的，以调查支持病原体社区的种间相互作用。此外，牙周炎的动物模型是必需的，其中可以研究类人社区的致病潜力。在这项提案中，我们将利用最近获得的关于牙周炎患者微生物组组成的知识，开发一个20种模型龈下群落。该模型将在与体内相似的营养和环境条件下连续培养。使用这个社区模型，我们将调查种间相互作用的牙周炎相关物种的生存重要。特别是，我们将测试一组所谓的“龈下核心物种”，这是健康和疾病的社区的重要组成部分，并可能作为社区代谢锚支持牙周炎相关类群的作用。然后，我们将评估模型20种社区在小鼠口腔中的定植和致病性，测试的假设，即微生物生长作为一个社区和预适应环境压力，如氧气能够更好地殖民和诱导牙周炎比单一物种。因此，本提案的具体目的是：1）开发和表征代表牙周炎的基于恒化器的龈下群落模型，并测试核心物种作为牙周炎相关群落成员生存的基础的作用，以及2）开发牙周炎的基于群落的口服灌胃鼠模型。所提出的模型将在该领域产生巨大影响，因为它们将使牙周炎发病机制的研究超越单一物种的研究，从而有助于识别调节致病菌群建立及其对宿主组织影响的关键事件。这些知识可能会指导牙周健康保护新策略的发展。

DESCRIPTION (provided by applicant): Periodontitis is an inflammatory condition of the supporting tooth structures that results from the interaction of pathogenic subgingival communities with the host. The pathophysiology of this condition is not completely understood and thus the development of novel preventive or therapeutic strategies remains elusive. Microbial communities are complex dynamic entities in which microorganisms interact with each other, therefore displaying different phenotypic characteristics than individual species. Moreover, a community context modifies the pathogenic potential of microorganisms, which is realized not only by their direct interaction with host tissues but also indirectly by modulating te behavior of the whole community. Therefore, understanding the etiology of periodontitis requires considering microbial communities as the infectious challenge rather than focusing on single species as causative agents. Community models that approximate the taxonomic complexity, environmental conditions and growth rate of microorganisms in the subgingival environment are not available. Such models are necessary to investigate the inter-species interactions that support pathogenic communities. Moreover, animal models of periodontitis are required in which the pathogenic potential of human-like communities could be investigated. In this proposal, we will use recently acquired knowledge on the microbiome composition of humans with periodontitis to develop a 20-species model subgingival community. This model will be developed under continuous culture in nutritional and environmental conditions similar to those in vivo. Using this community model we will investigate inter-species interactions important for the survival of periodontitis-associated species. In particular, we will test the role of a group called "subgingival core species" which are important components of communities in health and disease and potentially serve as community metabolic anchors by supporting periodontitis-associated taxa. We will then evaluate the colonization and pathogenicity of the model 20-species community in the murine oral cavity, testing the hypothesis that microorganisms growing as a community and pre-adapted to environmental pressures such as oxygen are better able to colonize and induce periodontitis than single species. Accordingly, the specific aims of this proposal are: 1) To develop and characterize a chemostat-based subgingival community model representative of periodontitis and test the role of core species as fundamental for the survival of periodontitis- associated community members and 2) To develop a community-based oral gavage murine model of periodontitis. The models proposed will have great impact in the field as they will allow research on the pathogenesis of periodontitis to move beyond the study of single species, thereby facilitating identification of key events that modulate the establishmen of pathogenic communities and their effects on host tissues. This knowledge is likely to direct the development of new strategies for preservation of periodontal health.