Molecular Imaging of Gingipain Activity in Advanced Periodontitis

项目摘要 该提议的目的是一种可激活的光声造影剂，以映射和测量 牙龈卟啉单胞菌在牙周炎期间释放的牙龈菌蛋白酶。虽然P. gingvalis很容易测量， PCR不能在口腔中定位。在这里，光声超声将用于报告数量和 定位牙龈卟啉单胞菌释放的牙龈蛋白酶，并改善诊断和对治疗的反应。我们 动机是研究表明，牙痛大大降低生活质量，但近50%的 美国人有某种形式的牙周炎。我们的理由是，目前监测口腔健康的方法 仅测量牙龈炎的结果和症状（牙齿脱落、牙周袋深度等）。我们认为， 成像和测量牙周病的分子原因-即，P. 牙龈炎-新的见解将获得这种情况的基本生物学以及更好的诊断和 治疗监测计划。这种改进的诊断洞察力将更好地指导治疗， 成像将增加患者的顺应性，最终转化为牙周炎的更早和更好的治疗。 工作流程将包括两个部分：Aim 1将构建造影剂，并使用重组 牙龈卟啉菌蛋白酶、细菌培养物和来自健康受试者的唾液。目标2将使用龈沟测试探针 Chen博士在常规清洁期间收集的液体（GCF）样本。我们将重悬这些样本， 使用目标1中验证的探针定量牙龈卟啉菌蛋白酶。我们假设， 我们的探针在体外将随牙龈卟啉菌蛋白酶浓度线性增加。我们假设光声 成像可以将GCF样品分层为口腔健康状态的函数。这种方法是创新的，因为 这种造影剂将是第一种用于牙周病的分子成像技术。它能检测疾病 在解剖损伤之前。因此，我们将能够绘制和测量致病活动的程度 引起的牙龈卟啉单胞菌在龈下空间在真实的时间。它还将在早期阶段对疾病进行分类。 目前的牙周图表只能评估袋深度和出血的探测，但检测早期- 阶段致病活性将允许容易和廉价的干预，以降低临床负担， 牙周炎和改善患者的结果。临床影响是一种检测早期变化的工具， 口腔微生物群来指导/监测治疗。这项技术也可以回答有关影响的问题， 牙龈卟啉酶对炎症、免疫负荷、牙周袋加深和牙槽骨原位丢失的影响。我们都好吗 由于Jokerst博士在光声造影剂方面的技能和Chen博士的 在南加州大学牙科学院的领导地位;我们已经发表了相关的研究。

PROJECT SUMMARY This objective of this proposal is an activatable photoacoustic contrast agent to map and measure the gingipain proteases released by P. gingivalis during periodontitis. While P. gingvalis is easy to measure with PCR it cannot mapped in the mouth. Here, photoacoustic ultrasound will be used to report the quantity and location of gingipains released by P. gingivalis and improve diagnosis and response to therapy. We are motivated by studies showing that dental pain dramatically decreases quality of life but that nearly 50% of Americans have some form of periodontitis. Our rationale is that current approaches to monitoring oral health only measure the results and symptoms of gingipains (tooth loss, pocket depth, etc.). We argue that by imaging and measuring a molecular cause of periodontal disease—i.e., the gingipains secreted by P. gingivalis—new insights will be gained into the basic biology of this condition as well as better diagnostic and treatment-monitoring plans. This improved diagnostic insight will better guide therapy, and non-invasive imaging will increase patient compliance ultimately translating into earlier and better treatment of periodontitis. The workflow will include two parts: Aim 1 will build the contrast agent and validate it with recombinant gingipains, bacterial culture, and saliva from healthy subjects. Aim 2 will test the probe with gingival crevicular fluid (GCF) samples collected by Dr. Chen during routine cleanings. We will resuspend these samples and quantitate the gingipains using the probe validated in Aim 1. We hypothesize that the photoacoustic signal of our probe will increase linearly with gingipain concentration in vitro. We hypothesize that photoacoustic imaging can stratify GCF samples as a function of oral health status. This approach is innovative because this contrast agent will be the first molecular imaging technique for periodontal disease. It will detect disease prior to anatomical damage. As such, we will be able to map and measure the extent of pathogenic activity caused by P. gingivalis in the subgingival space in real time. It will also triage the disease in early stages. Current periodontal charting can only assess pocket depths and bleeding on probing, but detection of early- stage pathogenic activity will allow easy and inexpensive intervention to lower the clinical burden of periodontitis and improve patient outcomes. The clinical impact is a tool to detect early-stage changes in the oral microbiota to guide/monitor therapy. This technique could also answer questions about the impact of gingipains on inflammation, immune loading, pocket deepening, and alveolar bone loss in situ. We all well positioned to perform this work because of Dr. Jokerst’s skills in photoacoustic contrast media and Dr. Chen’s leadership position at the USC School of Dentistry; we have already published together on related research.