IMMUNE MECHANISMS OF PULPAL RESISTANCE TO INFECTION

牙髓抵抗感染的免疫机制

• 批准号: 2331334
• 负责人: PHILIP Stashenko
• 金额: $ 28.93万
• 依托单位: ADA FORSYTH INSTITUTE, INC.
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-02-01 至 2000-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2331334
• 关键词: SCID mouse; antisense nucleic acid; bacterial disease; bactericidal immunity; biological response modifiers; cell adhesion molecules; cell migration; clinical research; cytokine; dental pulp; gene expression; gene targeting; glucans; human subject; immunocytochemistry; immunologic assay /test; inflammation; laboratory mouse; laboratory rabbit; leukocyte activation /transformation; neutrophil; nucleic acid sequence; polymerase chain reaction; pulp disorder; vascular endothelium

Infection of the dental pulp occurs as a sequellum of caries, trauma, or operative dental procedures, and may result in pulpal necrosis and the need for endodontic therapy and associated restorative procedures. Both antigen-specific and non-specific immune responses occur in dental pulps and in the periapical region in response to these infections. Information from the literature and our own preliminary studies indicate that antigen- specific responses mediated by T and B lymphocytes do not appear to exert a clear protective role in pulpal immunity. Instead, non-specific immune mechanisms, in particular phagocytic polymorphonuclear leukocytes (PMNs), appear to be a key element in the resistance of the pulp to bacterial invasion and destruction. In the proposed studies, we will rigorously test the hypothesis that non-specific immune mechanisms, in particular PMNs, play a key protective role in the resistance of the pulp/periapical complex to infection. In AIM I, the role of specific immune responses will be assessed in RAG2 severe combined immunodeficient (SCID) vs. immunologically-intact control mice, using a well-established in vivo model. The inflammatory cell infiltrate and the expression of cytokines potentially important in tissue destruction and in crosstalk between the specific and non-specific systems will be characterized. In AIM 2, single and double knockout mice deficient in four cell adhesion molecules (CAMs), including P- and E-selectin, ICAM-1, and beta2 integrin (CD18), which are crucial for phagocytic cell adhesion to, and migration through, the endothelial lining of blood vessels, will be tested for effects on pulpal/periapical destruction in vivo. The studies in Aims I and 2 will establish, in a definitive way, the role of the specific vs non-specific arms of the immune response in pulpal protection. The effect of upregulating PMN function with the biological response modifier PGG glucan will be explored, with a focus on the local effects of this immunostimulator (AIM 3). A chamber model which mimics the infected pulp chamber will be utilized to determine the effect of PGG glucan on the emigration, activation, and anti-bacterial function of leukocytes. In AIM 4, the molecular mechanism(s) by which PGG-glucan upregulates phagocytic cell function-will be determined. Strategies for characterizing gene arrays modulated by PGG glucan will include differential screening and differential display by polymerase chain reaction. The functional relevance of identified gene products will be evaluated in antibody and antisense inhibition experiments. The ultimate goal of these studies is to determine whether protective modalities of the immune response can be manipulated to improve the success of vital pulp therapies, prevent pulpal destruction, and reduce the necessity for endodontic treatment.

牙髓的感染作为龋齿，创伤或 手术牙科手术，可能导致牙髓坏死和 需要牙髓治疗和相关的修复程序。两个都 牙髓中发生抗原特异性和非特异性免疫反应 以及对这些感染的响应根本区域。信息 从文献和我们自己的初步研究中表明，抗原 - T和B淋巴细胞介导的特定反应似乎不施加 在牙髓免疫中具有明显的保护作用。相反，非特异性免疫 机制，特别是吞噬多形核白细胞（PMN）， 似乎是果肉对细菌抗性的关键元素 入侵和破坏。在拟议的研究中，我们将严格测试 非特异性免疫机制，尤其是PMN的假设， 在纸浆/根尖的抗药性中起关键的保护作用 复合物感染。在目标I中，特定免疫反应的作用将 在RAG2严重合并免疫缺陷（SCID）中进行评估。 使用良好的体内，具有免疫学直立的控制小鼠 模型。炎症细胞浸润和细胞因子的表达 在组织破坏和串扰中可能很重要 特定和非特异性系统将被表征。在AIM 2中，单身 和双基因敲除小鼠缺乏四个细胞粘附分子（CAM）的小鼠， 包括p-和e-S-选择蛋白，ICAM-1和beta2整合素（CD18）， 对于吞噬细胞粘附至关重要，并迁移 血管内皮衬里，将测试对 体内牙髓/根尖的破坏。目标I和2的研究将 以明确的方式建立特定与非特异性的作用 牙髓保护中免疫反应的臂。效果 使用生物响应修饰符PGG葡萄糖上调PMN功能 将被探索，重点是当地效果 免疫刺激器（AIM 3）。模拟感染纸浆的室内模型 腔室将用于确定PGG葡萄糖对 白细胞的移民，激活和抗菌功能。目标 4，PGG葡萄糖上调吞噬细胞的分子机制 细胞功能将确定。表征基因的策略 由PGG Glucan调制的阵列将包括差分筛选和 通过聚合酶链反应的差异显示。功能 鉴定基因产物的相关性将在抗体和 反义抑制实验。这些研究的最终目标是 确定免疫反应的保护方式是否可以 被操纵以改善重要牙髓疗法的成功，防止牙髓 破坏，并减少牙髓治疗的必要性。