P. gingivalis-specific T cells in mice prone and resistant to periodontitis

描述(申请人提供)：牙周炎是一种慢性炎症性疾病，影响30-40%的美国人口。它是导致牙周组织破坏和牙齿脱落的主要原因。到目前为止，我们还不能准确地预测哪些人将来会发生牙周骨破坏，导致大多数牙科患者接受不必要的治疗并暴露在不必要的风险中。牙周微生物群不断挑战免疫系统，在某些情况下导致慢性炎症，最终可能导致牙槽骨破坏。在骨损伤发生之前抑制这种免疫反应必须成为预防的目标。我们的长期目标是确定在口腔感染牙周病原体后，使个体容易破坏牙齿周围结缔组织和骨骼的细胞免疫表型。我们目前的目标是研究两种牙龈卟啉单胞菌(RgpA和Kgp)在牙周骨质破坏敏感(BALB/c)或耐药(C57BL/6)小鼠体内的CD4+效应T细胞的活化和表型。我们假设，在遗传易感疾病的小鼠中，RgpA和Kgp特异性的CD4+T辅助细胞(Th)分化为骨破坏性干扰素？产生Th1细胞，并在牙周骨破坏开始后转化为Th17表型。为了验证这一假设，我们将首先使用一种新的抗原特异性四聚体染色，来确定R/KGP特异性效应和调节性CD4+T细胞的激活和表型的动力学，以及Pggp定植的BALB/c和C57BL/6小鼠的牙槽骨破坏的相对数量。同时，我们将确定炎症细胞在边缘牙龈中渗透的性质和时间。其次，我们将通过一系列过继转移实验来确定R/KGP特异性效应Th细胞对骨水平的直接影响。总而言之，这些数据将定义哪种表型的R/KGP特异性Th细胞将驱动每个小鼠品系的骨破坏或保护动力学。此外，这些结果将支持随后的R01应用，测试细胞因子和RANKL(由R/KGP特异的CD4+T细胞或同型转换B细胞产生)对牙槽骨稳态的影响，以及对牙周骨破坏敏感或抵抗的小鼠品系的边缘牙龈内天然免疫的作用。建立一个预测未来牙周骨破坏的框架，对于了解牙周病进展的发病机制，定制牙周治疗，并最终开发牙周炎黏膜疫苗至关重要。

DESCRIPTION (provided by applicant): Periodontitis is a chronic inflammatory disease that affects 30-40% of the U.S. population. It is the leading cause of periodontal tissue destruction and tooth loss. To date, we cannot accurately predict which individuals will develop future periodontal bone destruction, leading most dental patients to undergo unnecessary treatment and exposure to undue risk. The periodontal microbiota constantly challenges the immune system, leading, in some cases, to chronic inflammation that may end in alveolar bone destruction. Inhibiting such immune responses before bone damage occurs must become the target of prevention. Our long-range goal is to define the cellular immune phenotype that predisposes an individual to destruction of the connective tissue and bone around teeth subsequent to oral infection with periodontal pathogens. Our current objective is to study the kinetics of activation and phenotype of CD4+ effector T cells specific for two Porphyromonas gingivalis gingipains (RgpA and Kgp) in a mouse strain susceptible (BALB/c) or resistant (C57BL/6) to P. gingivalis-mediated periodontal bone destruction. We hypothesize that in mice genetically susceptible to disease, RgpA- and Kgp-specific CD4+ T helper (Th) cells differentiate into bone destructive IFN-? producing Th1 cells, and into a Th17 phenotype after periodontal bone destruction has been initiated. To test this hypothesis we will use a novel antigen-specific tetramer stain to first, determine the kinetics of activation and phenotype of R/Kgp-specific effector and regulatory CD4+ T cells and the relative amount of alveolar bone destruction in P. gingivalis-colonized BALB/c and C57BL/6 mice. Concurrently, we will define the nature and timing of inflammatory cell infiltrate in the marginal gingiva. Second, we will identify the direct effect of R/Kgp- specific effector Th cells on bone levels using a series of adoptive transfer experiments. Collectively, these data will define which phenotype of R/Kgp-specific Th cells will drive the kinetics of bone destruction or protection in each mouse strain. Furthermore, these results will underpin a subsequent R01 application testing the effect of cytokines and RANKL, specifically produced by R/Kgp-specific CD4+ T cells or isotype-switched B cells, on alveolar bone homeostasis and the role of innate immunity within the marginal gingiva in mouse strains that are susceptible or resistant to periodontal bone destruction. Establishing a framework to predict future periodontal bone destruction is crucial to understanding pathogenesis of periodontal disease progression, customizing periodontal treatment, and ultimately developing a mucosal vaccine against periodontitis.