IL-8 AND PERIODONTAL DISEASES

我们的目标是定义一种可能的“共同受体缺陷” 在许多中性粒细胞功能改变的报道中，患者患有 来自局限性青少年牙周炎(LJP)。在这项研究中，我们建议 识别和表征常见的结构和功能基序 在类似的中性粒细胞(PMN)膜成分中，如受体 对于IL-8、C5a和FMLP。我们还建议刻画一个泛函 LJP患者外周血中中性粒细胞对IL-8的反应 相关趋化细胞因子NAP-2和Gro/MGSA。白介素2受体 8、C5a和FMLP在细胞激活中发挥关键作用，并一直 据多名调查人员报道，慢性阻塞性肺疾病患者的中性粒细胞发生了变化 LJP。这些化学诱导剂的受体共享一些结构和 膜中分子排列等功能特征， 对细胞反应和/或膜信号传递和配体的影响 互动。我们假设在LJP中有一个共同的潜在因素 细胞相关缺陷，无论是在受体水平，还是在POST 受体/膜水平。我们进一步提出，这种分子缺陷 可能与报告的这些患者的PMN反应改变有关 还有他们的兄弟姐妹。 我们的具体目标是描述人类的功能领域 白介素8受体参与配体结合和 通过激活G蛋白进行信号转导。白介素8 受体被选为模型，因为其配体(IL-8)参与了 大多数中性粒细胞对细菌感染和炎症有反应，我们 假设它是调节牙周的中枢细胞因子 感染。这一功能特征将通过以下方式进行： A)构建与不同部分相对应的合成肽 IL-8受体分子，以及b)定点突变和 突变重组受体的功能鉴定。我们也 建议确定编码区的染色体定位(S) 白介素8受体。了解功能域以及 这种受体的结构和遗传组织将导致 更好地理解PMN在宿主反应中的作用，以及基础知识 细胞激活的机制。开始寻找一个“共同的” 分母缺陷“一文中，我们建议刻画一种功能轮廓 LJP中性粒细胞对IL-8的反应及功能相似的趋化作用 细胞因子NAP-2和Gro/MGSA，特别强调配体结合， 受体分布和跨膜信号转导。到时候我们会的 这些变化与FMLP和C5a受体的表达有关。 这些研究旨在更好地了解 LJP中性粒细胞异常及其在疾病中的作用 敏感度。此外，对IL-8受体功能的了解 结构域可以允许设计具有激动剂或拮抗剂的肽 有可能改变IL-8引起的炎症反应。优势所在 这一提议的基础是结合了分子生物学 结合大量临床研究探讨具有良好特点的 LJP患者。

Our goal is to define a possible "common receptor defect" which results in many neutrophil functional alterations reported for patients suffering from Localized Juvenile Periodontitis (LJP). In this study, we propose to identify and characterize common structural and functional motifs among similar neutrophil (PMN) membrane components such as the receptors for IL-8, C5a, and FMLP. We also propose to characterize a functional profile of PMN from LJP patients in response to IL-8, and the closely related chemotactic cytokines NAP-2 and GRO/MGSA. The receptors for IL- 8, C5a, and FMLP play a critical role in cell activation, and have been reported by various investigators to be "altered" in PMN of patients with LJP. The receptors for these chemoattractants share some structural and functional features such as molecular arrangement in the membrane, effects on cell response, and/or membrane signal transmission and ligand interactions. We hypothesize that in LJP there is a common underlying cell-associated defect, either at the receptor level, or at post receptor/membrane level. We further propose that this molecular defect may contribute to the altered PMN response reported for these patients and their siblings. Our specific aims are to characterize the functional domains of the human interleukin-8 (IL-8) receptor which are involved in ligand binding and in signal transduction through activation of G proteins. The IL-8 receptor was selected as a model since its ligand (IL-8) is involved in most PMN responses to bacterial infections and inflammation, and we hypothesize that it is a central cytokine in modulating periodontal infections. This functional characterization will be carried out by: a) constructing synthetic peptides corresponding to different portions of the IL-8 receptor molecule, and b) site-directed mutagenesis and functional characterization of mutated recombinant receptor. We also propose to define the chromosomal localization of the coding region(s) of the IL-8 receptor. Understanding the functional domains as well as the structural and genetic organization of this receptor will lead to better understanding of PMN function in host responses, as well as basic mechanisms of cell activation. To begin the search for a "common denominator defect", we propose to characterize a functional profile of LJP PMN in response to IL-8, and the functionally similar chemotactic cytokines NAP-2 and GRO/MGSA, with particular emphasis on ligand binding, receptor distribution, and transmembrane signaling. We will then correlate these profiles with expression of FMLP and C5a receptors. These studies are designed to provide a better understanding of abnormalities in LJP neutrophils and the role they play in disease susceptibility. In addition, knowledge of the IL-8 receptor functional domains may allow design of agonists or antagonist peptides with the potential to modify IL-8 induced inflammatory reactions. The strength of this proposal is the combination of a basic molecular biological approach with clinical studies of a large number of well characterized LJP patients.