Making a quantum leap in plaque research with modern sciences

 描述（由申请人提供）：目前认为变形链球菌是一种主要致龋细菌的知识主要基于人龋齿率与变形链球菌水平的相关性。口腔中的变形菌或通过接种诱导龋齿。各种动物模型中的变异体。这一证据是实质性的，但不是决定性的，因为S。口腔中有数百种细菌，变形菌只是其中之一。传统的方法集中在单和双物种的相互作用是有价值的，但根本不能提供明确的答案是否S。变形杆菌是负责维持口腔微生物群落的致龋性或使其向疾病状态转变的“关键致龋病原体”。在上一个周期中，我们开发了最先进的技术（如宏基因组学指导的社区模型开发，将SIP与实时NMR代谢组学相结合，细菌表面显示pH敏感的绿色荧光蛋白），能够原位和实时同时检测口腔细菌（包括不可培养的细菌）及其在多物种牙菌斑中的酸性代谢产物。通过连接S.针对变形链球菌信息素CSP的抗菌肽，我们构建了一个具有高度特异性和敏感性的靶向抗菌肽C16 G2。变异人我们通过选择性膜破坏证明了其杀伤能力，并验证了其安全性。这些最近开发的工具提供了新的生物学见解，将关键细菌和功能与多物种环境中的致龋过程联系起来。从这些研究中得出的有趣和有趣的结果提供了一个强有力的证据，S。变形杆菌，具有协调其三个关键致龋毒力因子的能力 （葡聚糖产生、产酸性和酸度），可以大大增强其对酸胁迫的适应性，这可能是其能够破坏口腔微生物群落的正常稳态并将条件推向疾病状态的原因。基于我们令人兴奋的初步数据，我们提出了以下两个工作假设来解决这些问题：1）S。变形链球菌具有独特的能力，整合其三个主要毒力因子（葡聚糖产生、产酸性和酸度），以增强其在低pH下的适应性，这可能是维持口腔微生物群落致龋活性的原因; 2）有针对性地去除变形链球菌。变形菌可以重建健康的口腔微生物群落。本申请的目的是在体外和体内条件下使用组合的基因组、遗传、生物化学和生理学研究来测试我们的假设。这项研究的成功将大大扩大我们的知识，口腔微生物的发病机制，揭示了综合毒力功能，促进生存和持久的S。变异人通过我们新的治疗干预措施，它也将对龋齿的临床管理产生直接和直接的影响。

 DESCRIPTION (provided by applicant): The current knowledge implicating Streptococcus mutans as a major cariogenic bacterium is mainly based on the correlation of human caries rates vs levels of S. mutans in oral cavities or the induction of dental caries via inoculation of . mutans in various animal models. This evidence is substantial but not conclusive as S. mutans is just one of the hundreds of species in oral cavity. Traditional approaches focused on single and dual species interactions are valuable but simply cannot provide the definitive answer on whether or not S. mutans is the "keystone cariogenic pathogen" responsible for maintaining or shifting the cariogenicity of the oral microbial community towards the disease state. In the previous cycle, we developed state-of-the-art technologies (such as metagenomic-guided community model development, combined SIP with real-time NMR metabolomics, bacterial surface-displayed pH-sensitive green fluorescent protein) that enabled simultaneous detection of oral bacteria (including uncultivable bacteria) and their acidic metabolites within multi-specie dental plaque in situ and in real-time. By connecting S. mutans' pheromone CSP to an antimicrobial peptide, we created a targeted antimicrobial peptide C16G2 with high specificity and sensitivity against S. mutans. We demonstrated its killing ability via selective membrane disruption and validated its safety. These recently developed tools provided new biological insights connecting key bacteria and functions to the cariogenic process in multi-species settings. The interesting and intriguing results derived from these studies provided a strong indication that S. mutans, with an ability to coordinate its three key cariogenic virulence factors (glucan production, acidogenicity and acidurity), can greatly enhance its fitness against acid stress, which could be the reason for its ability to disrupt the normal homeostasis of the oral microbial community and drive conditions towards a disease state. Based on our exciting preliminary data, we developed the following two working hypotheses to address these questions: 1) S. mutans has unique capacities to integrate its three major virulence factors (glucan production, acidogenicity and acidurity) to enhance its fitness in low pH than other oral species, which may be responsible for maintaining the cariogenic activity of the oral microbial community; 2) The targeted removal of S. mutans would allow the reestablishment of the healthy oral microbial community. This application aims to test our hypothesis using a combined genomic, genetic, biochemical and physiological study under both in vitro and in vivo conditions. The success of this study would greatly expand our knowledge of oral microbial pathogenesis by uncovering integrated virulence functions that facilitate survival and persistence of S. mutans. It will also have a direct and immediate impact on the clinical management of dental caries through our new therapeutic interventions.