LPS-MONOCYTE INTERACTIONS IN PERIODONTAL DISEASE

人单核巨噬细胞(HMP)可在 牙周病变的组织，可以被刺激释放 生理上有意义的花生四烯酸(AA)代谢物 包括前列腺素E2(PGE2)和血栓素B2(TSB2)。PGE2有 与牙周病特别相关，因为它有能力 刺激骨吸收，调节免疫功能。细菌 内毒素，一种复杂的内毒素，参与了 牙周病的发病机制，是再生障碍性贫血的有力刺激因素 HMP的代谢物释放。然而，内毒素的作用机制 对HMP中AA代谢的调节几乎仍未被探索。的目标是 本提案详细研究了内毒素对AA代谢物释放的调节 来自HMP。本提案中要解决的具体问题包括1)内毒素 无C3b对HMP释放AA代谢物的刺激作用 刺激效应，2)前列腺素E_2明显的细胞区域化 脂多糖刺激HMP产生和释放TXB_2， 3)HMP是否含有大量的醚酰基和烷基酰基 磷脂以及内毒素是否选择性地调节这些细胞的AA释放 脂类。初步实验将表征时间和剂量依赖关系 几种脂多糖刺激HMP后代谢产物的释放 制剂包括具有生物活性的脂类A部分脂多糖。AA 代谢物的释放将通过RIA以及通过产生 用~3H-AA和/或14C-AA预先标记HMP后标记的代谢物。 此外，还将对HMP磷脂含量进行广泛表征 特别强调了醚酰基和烷基酰基磷脂的含量。 然后，标记代谢物出现的时间进程将被关联 随着磷脂标记的改变。这些研究将提供 对内毒素和HMP之间的生物相互作用的更多见解和 将为单核/巨噬细胞的作用提供额外的支持 慢性炎症性疾病过程包括牙周病。

Human mononuclear phagocytes (HMP) can be identified in elevated numbers in periodontally diseased tissues and can be stimulated to release physiologically significant amounts of arachidonic acid (AA) metabolites including prostaglandin E2 (PGE2) and thromboxane B2 (TSB2). PGE2 has particular relevance to periodontal disease due to its capacity to stimulate bone resorption and regulate immune function. Bacterial endotoxin, a complex lipopolysaccharide (LPS) implicated in the pathogenisis of periodontal disease, is a potent stimulator of AA metabolite release from HMP. However, the mechanisms by which LPS regulates AA metabolism in HMP remains virtually unexplored. The goal of this proposal is examine in detail LPS regulation of AA metabolite release from HMP. Specific points to be addressed in this proposal include 1) LPS stimulation of AA metabolite release from HMP in the absence of C3b stimulatory effects, 2) the apparent cellular compartmentalization of PGE2 and TXB2 production and release from HMP following stimulation with LPS, and 3) whether HMP possess significant amounts of ether-acyl and alkyl-acyl phospholipids and whether LPS selectively regulates AA release from these lipids. Initial experiments will characterize time and dose dependent metabolite release from HMP following stimulation with several LPS preparations including the biologically active lipid A moiety of LPS. AA metabolite release will be monitored by RIA as well as by the production of labelled metabolites following HMP prelabelling with 3H-AA and/or 14C-AA. In addition, HMP phospholipid content will be extensively characterized with specific emphasis on ether-acyl and alkyl-acyl phospholipid content. The time course of labelled metabolite appearance will then be correlated with alterations in phospholipid labelling. These studies will provide additional insight into the biological interaction between LPS and HMP and will provide additional support for the role of the monocyte/macrophage in chronic inflammatory disease processes including periodontal disease.