Regulatory B cells in the amelioration of immune-mediated periodontal disease

描述(申请人提供)：牙周炎是一种炎症性疾病，由宿主对牙周生物膜中的致病微生物产生免疫反应而引发，导致牙齿松动和随后的脱落，并增加各种系统性疾病的发展风险。目前的治疗方法不能完全改善牙周组织的破坏，因为它们没有直接解决牙周发病的生物学原因--不平衡的、过度侵略性的免疫反应。在牙周炎发展为昂贵和难治性疾病之前，开发有针对性的免疫干预措施来治疗牙周炎是一个令人信服的兴趣。具有调节功能的B细胞(Breg)在免疫系统平衡中起关键作用，通过抑制促炎细胞因子和促进调节性T细胞分化来抑制过度的炎症反应。这个项目的目标是 研究Toll样受体(TLR)激动剂和共刺激分子对BREG的体外激活和扩增作用，并在实验性牙周病小鼠模型上测试这些BREG在体内改善牙周骨吸收的作用。然后，我们将使用人外周血单个核细胞(PBMC)和牙周单个核细胞(GMC)在体外表征人BREG的表型和免疫调节功能。该项目的中心假设是，增强局部Breg功能可以减少免疫介导的牙周病骨丢失。这三个相互关联和相互重叠的特定目标是：1)确定小鼠脾和腹膜腔中BREG的激活和扩增，并鉴定可用于定义此类群体的表型标记。重点将是多个TLR(TLR2、4和9)之间的相互作用对BREG的激活以及这种BREG如何在体外扩增。2)用小鼠牙周病模型评价体内转运及过继转导Breg对牙周骨吸收的影响。将特别强调转移的Breg对局部炎症的牙龈组织中RANKL产生的影响。3)从健康人和疾病患者的PBMC体外激活和扩增人BREG，并更明确地评估所提出的方案对牙周炎患者GMC的有效性。对与持续疾病相关的GMC的研究将使我们能够以类似于疾病期间治疗的方式确定最有希望的方案对BREG的效果，作为转化应用的第一步。该项目的成功完成有望为BREG导向的改善牙周炎发病机制的转译研究铺平道路，这是由于不平衡的、过度侵袭性的免疫反应所致。选择性促进局部Breg功能的新策略可能使治疗师能够有效地治疗对当前治疗耐药的牙周病患者。

DESCRIPTION (provided by applicant): Periodontitis is an inflammatory disease triggered by host immune response to pathogenic microorganisms in the periodontal biofilm, leading to the loosening and subsequent loss of teeth, and increased risk for the development of various systemic conditions. Current treatments do not offer complete amelioration of periodontal tissue destruction because they do not directly address the biological causes of periodontal pathogenesis -- unbalanced, overly aggressive immune responses. There is compelling interest in developing targeted immunological interventions to treat periodontitis before it progresses to an expensive and refractory disease. B cells with a regulatory function (BREG) play a key role in immune system balance, restraining the excessive inflammatory responses by inhibiting pro-inflammatory cytokines and promoting regulatory T cell differentiation. The goal of this project is to characterize in vitro activated and expanded BREG in response to Toll-like receptor (TLR) agonists and co-stimulatory molecules, and to test these BREG to ameliorate periodontal bone resorption in vivo in a mouse model of experimental periodontal disease. We will then characterize the phenotype and immune regulatory function of human BREG in vitro using human peripheral blood mononuclear cells (PBMC) and gingival mononuclear cells (GMC). The central hypothesis of this project is that enhancing local BREG function can reduce immune-mediated periodontal disease bone loss. The three related and overlapping specific aims are: 1) Determine the activation and expansion of BREG from mouse spleen and intraperitoneal cavity and characterize the phenotypic markers that can be used to define such populations. The focus will be the interactions among multiple TLRs (TLR2, 4 and 9) on the activation of BREG and how such BREG be expanded in vitro. 2) Evaluate in vivo trafficking and the effects of adoptively transferred BREG on periodontal bone resorption using a mouse model of periodontal disease. Particular emphasis will be on the effect of transferred BREG on the RANKL production in local inflamed gingival tissues. 3) Characterize in vitro activated and expanded human BREG from PBMC of healthy and diseased individuals and more definitively, evaluate the effectiveness of the proposed regimes on GMC from periodontitis patients. Study of GMC associated with ongoing disease will enable us to determine the effect of the most promising regimens on BREG in a manner similar to treatment during disease, as the first step towards translational applications. Successful completion of this project would be expected to pave the way for translational research to delineate BREG-directed amelioration of periodontitis pathogenesis due to the unbalanced, overly aggressive immune responses. Novel strategies to selectively promote local BREG function may enable therapeutics to effectively treat patients with periodontal diseases that are resistant to current therapy.