C5A/IL 8 AND ADULT PERIODONTAL DISEASE

C5A/IL 8 和成人牙周病

• 批准号: 2458627
• 负责人: TONY E HUGLI
• 金额: $ 21.77万
• 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/2458627
• 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 涉案我们的假设是，体液炎症因子C5 a， 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起重要作用， 细菌感染。这一进程可以由 厌氧革兰氏阴性菌或它们制造的蛋白酶。 虽然补体激活可以直接通过接触 在血浆和细菌颗粒之间，我们提出细菌 蛋白酶主要负责C5 a的延长产生， 牙周病强效趋化因子C5 a/f-MLF募集 嗜中性粒细胞和巨噬细胞，其又释放蛋白酶、IL-8和 加速组织降解并促进 水肿持续性水肿，由于血浆液体从 牙周组织的微血管是牙周炎的常见特征， 疾病血浆蛋白滤液中含有C5，C5可被 细菌蛋白酶，从而释放趋化因子C5 A。 局部炎性细胞隔离的延长与 假设正在进行的C5 a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， 配制的肽）和/或体液（即C5 a）趋化因子， 引发细胞渗透的级联反应最初的细胞 流入可能会放大后，在这个过程中，由细胞衍生的趋化性 因子如PAF、IL-8和LTB 4。该提案旨在首先 在损伤部位证明C5 a/IL-8的证据，检查 细菌产物（即蛋白酶）对各种活化因子的影响 和它们的受体，然后检验C5 a/IL-8 参与实际发生，并有助于促进 这种疾病第二，我建议具体评估进程， 作为细菌内毒素对中性粒细胞/巨噬细胞的“致敏”， 增强细胞对趋化因子的反应性。C5 a和IL-8 最近在培养的上皮细胞（HEp-2）上证实了受体 和KB）和人牙龈组织中的上皮细胞（参见初步的 结果部分）。抗C5 a/IL-8和抗C5 a/IL-8受体 抗体，能够中和结合和体内细胞 移民，已经发展。这些试剂将用于探索 来自牙龈卟啉单胞菌的蛋白酶对趋化因子的作用， 他们的受体。我们已经表明，精氨酸和赖氨酸牙龈卟啉菌蛋白酶都降解 C3和C5并产生生物活性C5 a（见初步结果部分）。 此外，我们观察到，氧自由基处理C5 显著增强了牙龈卟啉菌蛋白酶的C5 a生成（手稿， 制备）。我们建议探索可能的C5 a/IL-8诱导上皮细胞 细胞功能，包括急性期蛋白的释放， 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因子介导的， 了解这些事件可能会导致治疗上有用的模式， 干预