MOLECULAR ANALYSIS OF MACROPHAGE ACTIVATION VIA LBP:LPS

CD 14是一种骨髓单核细胞分化抗原， 单核细胞表面，粒细胞表面较弱。 CD 14最近 已被证明是一种复合物的受体， 脂多糖（LPS）和称为LBP的急性期血清蛋白 （脂多糖结合蛋白）。 LBP：LPS复合物与 单核细胞通过CD 14导致巨噬细胞的强烈活化， 通过肿瘤坏死因子（TNF）的产生来测量。 激活 巨噬细胞通过这一途径被认为是初始步骤， 在内毒素休克中发现TNF的产生并介导 心血管肺肾系统 其主要目标是 建议是确定可溶性形式的CD 14是否可以抑制 通过LBP：LPS途径激活巨噬细胞，并进一步确定这一点 在分子水平上通过绘制巨噬细胞活化的途径， LBP：CD 14分子上的LPS结合位点。 此外，我们将定义 可以通过这种途径减少和/或抑制巨噬细胞活化的肽 通路 将在体外分析可溶性CD 14及其肽， 以及体内抑制LPS诱导的巨噬细胞活化的能力 和/或由于内毒素休克而死亡。 体内实验将 利用我们最近生产的转基因小鼠， 表达人CD 14，比正常人更易受LPS影响 小鼠 该提案的长期目标是使用CD 14肽来 减少和/或抑制革兰氏阴性脓毒性休克中TNF的产生， 允许患者有时间对适当的药物做出反应的前景 替代疗法

CD14 is a myelomonocytic differentiation antigen expressed strongly on the surface of monocytes and weakly on granulocytes. CD14 has recently been shown to be a receptor for a complex consisting of lipopolysaccharide (LPS) and an acute phase serum protein called LBP (lipopolysaccharide binding protein). Binding of LBP:LPS complex to monocytes via CD14 results in strong activation of macrophages as measured by the production of tumor necrosis factor (TNF). Activation of macrophages by this pathway is thought to be the initial step in the production of TNF found in endotoxic shock and mediating the collapse of the cardiovascular-pulmonary-renal systems. The primary goals of this proposal are to determine whether soluble forms of CD14 can inhibit macrophage activation via the LBP:LPS pathway and to further define this pathway of macrophage activation at the molecular level by mapping the LBP:LPS binding site on the CD14 molecule. In addition, we will define peptides which can reduce and/or inhibit macrophage activation via this pathway. Soluble CD14 and its peptides will be analyzed both in vitro and in vivo for the ability to inhibit LPS-induced macrophage activation and/or death due to endotoxin shock. The in vivo experiments will utilize a transgenic mouse which we have recently produced which expresses human CD14 and which is more susceptible to LPS than normal mice. The long term goal of this proposal is to use CD14 peptides to reduce and/or inhibit TNF production in gram negative septic shock with the prospect of allowing time for the patient to respond to appropriate alternative therapy.