Macrophage response to LPS in periodontal disease

目前的概念表明，单核细胞/巨噬细胞对细菌LPS刺激的反应至少部分地介导了牙周病的进展和严重程度。特别是，促炎细胞因子，如il -1 β和TNFalpha，以及其他炎症介质（PGE2）的产生升高，似乎会导致依恋丧失的进展。据报道，在糖尿病患者中，内源性或组成性细胞因子对LPS的反应高于正常水平。与牙周病进展相关的细胞因子反应也明显高于非糖尿病人群。巨噬细胞上主要的LPS结合蛋白是CD14。巨噬细胞对LPS的细胞因子反应已知部分由CD14介导，尽管使用抗CD14抗体的抑制实验显示仅部分阻断。此外，CD14是一种糖基磷脂酰肌醇（GPI）锚定蛋白，没有穿过细胞膜的信号。基于鉴定Toll样受体（TLR）蛋白，特别是TRL4，作为LPS结合蛋白和LPS与moesin结合诱导IL-1和TNF生成的实验，已经假设了第二类LPS受体。moesin抗体完全消除了CD14介导的LPS反应，这在一定程度上负责CD14结合事件的信号转导。我们的假设是moesin是CD14 /Toll LPS受体复合物的一个组成部分。此外，该分子的表达和功能在糖尿病及其并发症（包括牙周炎）的发病过程中起重要作用。由于参与该反应的分子尚未完全表征，我们将首先对正常细胞中的LPS受体和共受体进行表征，然后再对糖尿病患者的细胞进行研究。因此，本提案的具体目的是表征CD14， LPS结合蛋白（LBP）， toll样受体（TRL4）和moesin之间的分子结构/功能关系。

Current concepts suggest that the monocyte/macrophage response to bacterial LPS stimulation mediates, at least in part, the progression and severity of periodontal disease. In particular, elevated production of pro- inflammatory cytokines, such as IL-1beta and TNFalpha, and other inflammatory mediators (PGE2), appears to result in progression of attachment loss. In the diabetic patient, the intrinsic or constitutive cytokine response to LPS has been reported to be elevated above normal. The cytokine response associated with progression of periodontal disease is also markedly higher than in the non-diabetic population. The major LPS binding protein on macrophages is CD14. The cytokine response in macrophages to LPS is known to be mediated in part by CD14, although inhibition experiments using anti-CD14 antibody reveal only partial blocking. In addition, CD14 is a glycosylphosphatidylinositol (GPI) anchored protein without a signal across the cell membrane. A second class of LPS receptor has been hypothesized based on experiments identifying Toll like receptor (TLR) proteins, particularly TRL4, as LPS binding proteins and LPS binding to moesin induces both IL-1 and TNF production. Antibody to moesin ablates the CD14 mediated LPS response completely which is, in part, responsible for signal transduction of CD14 binding events. Our hypotheses is that moesin is a component of the CD14 /Toll LPS receptor complex. Further, that the expression and function of this molecule plays an important role in the pathogenesis of diabetes mellitus and it's complications, including periodontitis. Since the molecules involved in this response are not fully characterized, we will first pursue the characterization of LPS receptors and co-receptors in normal cells and then proceed to cells from the diabetic patient. The Specific Aims of this proposal, therefore, are to characterize the molecular structure/function relationship between CD14, LPS binding protein (LBP), Toll-like receptors (TRL4) and moesin.