A novel mechanism of virulence control in Porphyromonas gingivalis

摘要 牙龈卟啉单胞菌是严重成人牙周炎的主要病原体， 一个复杂的微生物群落的协调作用，导致组织炎症，支持 牙齿.限制牙周病研究进展的一个主要障碍是缺乏详细的信息， 与从健康到疾病的临床进展相关的微生物信号。为了填补这个空白，我们 最近报道的metatranscriptome发现的微生物群落从人类临床样本， 牙周病的进展，并发现CRISPR（定期间隔短 在牙周病病原体牙龈卟啉单胞菌中，回文重复序列）相关蛋白仅在 在那些取得进展的地点。CRISPRs-Cas系统被细菌用来阻止外来DNA 合并，如病毒攻击所发生的。这项研究计划的目标是了解 CRISPR-Cas系统对疾病期间重要牙周病原体的毒力决定因素 进展对突变体的全面分析将提供必要的信息， 不仅要了解CRISPR基因的功能，还要了解这些新基因对毒力的贡献。到 为此，我们提出以下具体目标： 目标1。比较野生型和突变体的转录组谱，鉴定靶向内源基因 在细胞内生长 目标二。确定CRISPR相关基因对先天免疫宿主对P. 牙龈炎 目标3。目标3：确定CRISPR-Cas基因在牙龈卟啉单胞菌致病性中的作用。 我们希望这些知识将有助于制定有针对性的方法来预防和治疗 牙周炎通过抑制对毒力至关重要的特定Cas蛋白。这些成果将从根本上推动我们的 了解到这些系统除了它们的传统作用之外，还在牙周病原体的代谢中起作用 作为一种保护机制来抵御外来DNA。我们相信我们为此组建的团队 项目具有成功实现本申请中提出的目标的所有资格。

Abstract Porphyromonas gingivalis is a major pathogen of severe adult periodontitis, a polymicrobial disease caused by the coordinated action of a complex microbial community that leads to inflammation of tissues supporting the teeth. A central hurdle limiting progress in periodontal disease research is the paucity of information detailing microbial signals that correlate with clinical progression at a site from health to disease. Filling this void, we recently reported metatranscriptome findings of the microbial community from human clinical samples during periodontal disease progression and discovered that CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)-associated proteins in the periodontopathogen P. gingivalis were highly up-regulated only at those sites that progressed. CRISPRs-Cas systems are used by bacteria to prevent foreign DNA incorporation, as occurs with a viral attack. The goal of this research program is to understand the role that CRISPR-Cas systems have on virulence determinants of important periodontopathogens during disease progression. A comprehensive analysis of the mutants will provide information required to increase our understanding of not only CRISPR gene function, but also the contribution of these novel genes to virulence. To this end we propose the following Specific Aims: Aim 1. Identify targeted endogenous genes comparing transcriptome profiles of the wild-type and the mutants growing intracellularly. Aim 2. Determine the impact of CRISPR-associated genes on the innate immune host responses to P. gingivalis. Aim 3. Aim 3. Determine the role of CRISPR-Cas genes in the pathogenicity of P. gingivalis. We expect that this knowledge will facilitate the development of targeted approaches to prevent and treat periodontitis by inhibiting specific Cas proteins essential for virulence. Such results will fundamentally advance our understanding that such systems have in the metabolism of periodontal pathogens besides their traditional role assigned as a mechanism of protection against foreign DNA. We believe that the team we have assembled for this project has all the qualifications to accomplish successfully the goals proposed in the present application.