C5A/IL 8 AND ADULT PERIODONTAL DISEASE

C5A/IL 8 和成人牙周病

• 批准号: 2132018
• 负责人: TONY E HUGLI
• 金额: $ 20.95万
• 依托单位: SCRIPPS RESEARCH INSTITUTE, THE
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-09-30 至 1999-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2132018
• 关键词: Bacteroides gingivalis; activation product; acute phase protein; antireceptor antibody; bacterial proteins; cell type; chemoattractants; complement; cytokine receptors; endopeptidases; epithelium; gingiva; guinea pigs; human subject; interleukin 8; laboratory rabbit; laboratory rat; macrophage; neutrophil; pathologic process; periodontitis; periodontium disorder; protein degradation; receptor expression; tissue /cell culture

The role of complement in periodontal disease can be either protective or pathologic depending on the stage of the disease and the pathogens involved. Our hypothesis is that the humoral inflammatory factor C5a, the chemotatic cytokine IL-8 and/or formulated bacterial peptides (f-MLF) play a significant role in promoting gingival tissue injury resulting from bacterial infection. This process may be set in motion either by the anaerobic gram-negative bacteria or the proteases they elaborate. Although complement activation can be initiated directly by contact between plasma and bacterial particles, we propose that bacterial proteases are primarily responsible for prolonged generation of C5a in periodontal disease. The potent chemotactic factors C5a/f-MLF recruit neutrophils and macrophages which in turn release protases, IL-8 and other cellular cytokines that accelerate tissue degradation and promotes edema. Persistent edema due to leakage of plasma fluid from the microvasculature of the periodontium is a usual feature of periodontal diseases. Plasma protein filtrate contains C5 which may be degraded by bacterial proteases, with resultant release of the chemotaxin C5A. Prolongation of localized inflammatory cell sequestration is consistent with the hypothesis of ongoing C5a generation, which may contribute to the chronic inflammatory response that is the hallmark of periodontitis. The early events in periodontitis are likely driven by bacterial (i.e. formulated peptides) and/or humoral (i.e. C5a) chemotactic factors which initiate the cascade of cellular infiltration. The initial cellular influx may be amplified later in the process by cell-derived chemotactic factors such as PAF, IL-8 and LTB4. This proposal is designed to first demonstrate evidence for C5a/IL-8 at the injury site, examine effects of the bacterial products (i.e proteases) on the various activation factors and their receptors, and then test the hypothesis that C5a/IL-8 involvement actually occurs and contributes significantly in promoting the disease. Secondly, I propose to specifically evaluate processes such as "priming" of the neutrophils/macrophages by bacterial endotoxin, which enhances responsiveness of the cells to chemotactic factors. C5a and IL-8 receptors were recently demonstrated on cultured epithelial cells (HEp-2 and KB) and on epithelial cells in human gingival tissue (see preliminary results section). Both anti-C5a/IL-8 and anti-C5a/IL-8 receptor antibodies, capable of neutralizing binding and in vivo cellular migration, have been developed. These reagents will be used to explore the actions of the proteases from P.gingivalis on the chemotaxins and their receptors. We have shown that both Arg- and Lys-gingipain degrade C3 and C5 and generate bioactive C5a (see preliminary results section). In addition, we observed that oxygen radical treatment of C5 significantly enhanced C5a generation by the gingipains (manuscript in preparation). We propose to explore possible C5a/IL-8 induced epithelial cell functions including the release of acute phase proteins and cytokines. It is proposed that early events in the inflammatory response of periodontal disease are mediated by the chemotaxins and that understanding these events may lead to therapeutically useful modes of intervention.

补体在牙周病中的作用可以是保护性的 或病理性，取决于疾病的阶段和病原体 涉及。我们的假设是体液炎症因子 C5a 趋化细胞因子 IL-8 和/或配制的细菌肽 (f-MLF) 在促进牙龈组织损伤中发挥重要作用 来自细菌感染。这个过程可以由 厌氧革兰氏阴性细菌或它们产生的蛋白酶。 尽管补体激活可以通过接触直接启动 在血浆和细菌颗粒之间，我们建议细菌 蛋白酶主要负责延长 C5a 的生成时间 牙周病。有效的趋化因子 C5a/f-MLF 招募 中性粒细胞和巨噬细胞依次释放蛋白酶、IL-8 和 其他加速组织降解并促进 浮肿。由于血浆液从血浆中渗漏而导致持续性水肿 牙周组织的微血管结构是牙周病的一个常见特征 疾病。血浆蛋白滤液含有可被降解的 C5 细菌蛋白酶，从而释放趋化因子 C5A。 局部炎症细胞隔离的延长是一致的 假设 C5a 正在生成，这可能有助于 慢性炎症反应是牙周炎的标志。 牙周炎的早期事件可能是由细菌（即细菌）引起的。 配制的肽）和/或体液（即C5a）趋化因子 启动细胞浸润的级联反应。最初的蜂窝 在此过程的后期，细胞源性趋化作用可能会放大流入 PAF、IL-8 和 LTB4 等因子。该提案旨在首先 证明损伤部位存在 C5a/IL-8 的证据，检查 细菌产物（即蛋白酶）对各种激活因子的影响 及其受体，然后检验 C5a/IL-8 的假设 参与实际发生并在促进 这种疾病。其次，我建议专门评估诸如 作为细菌内毒素对中性粒细胞/巨噬细胞的“启动”， 增强细胞对趋化因子的反应性。 C5a 和 IL-8 最近在培养的上皮细胞（HEp-2 和 KB）以及人类牙龈组织中的上皮细胞（参见初步 结果部分）。抗 C5a/IL-8 和抗 C5a/IL-8 受体 抗体，能够中和结合并体内细胞 迁移，已开发。这些试剂将用于探索 牙龈卟啉单胞菌蛋白酶对趋化素的作用和 他们的受体。我们已经证明 Arg- 和 Lys-gingipain 都会降解 C3 和 C5 并生成具有生物活性的 C5a（参见初步结果部分）。 此外，我们观察到C5的氧自由基处理 牙龈蛋白酶显着增强了 C5a 的生成（手稿于 准备）。我们建议探索可能的 C5a/IL-8 诱导上皮细胞 细胞功能包括急性期蛋白的释放和 细胞因子。有人提出，炎症反应的早期事件 牙周病的发生是由趋化素介导的 了解这些事件可能会导致治疗上有用的模式 干涉。