ANTIBODY-MEDIATED HEPATOTOXICITY OF ETHANOL

乙醇的主要代谢产物乙醛已被证明 与蛋白质和磷脂上的氨基反应， N-乙胺加合物。 在蛋白质加合物形成的情况下， 由于乙醇的代谢，这些胺已被证明作为新抗原 并产生免疫反应 以前的研究表明， 血清中存在的抗体与 这些加合物和酒精相关的肝毒性。 我们最近的研究表明 一些在兔子体内产生的多克隆IgG抗体 乙醛的蛋白质加合物与合成的 乙酰胆碱-磷脂酰乙醇胺加合物（N-乙基-PE）。 如果 在酒精代谢过程中，在体内形成N-乙基-PE加合物， 交叉反应性抗体与暴露在表面上的这些加合物的结合 肝细胞表面可能有助于酒精相关的 肝毒性 本提案的目的是确定， 磷脂的乙醛加合物出现在 酒精暴露的肝细胞，如果抗体与它们结合， 由于嗜中性粒细胞活化导致肝细胞溶解，或 补体 描述了一系列步骤，这些步骤将确定 磷脂的乙醛加合物在体内形成时， 抗体与肝细胞的结合， 使用N-乙基-磷脂酰乙醇胺掺入其表面 流式细胞术，并测量免疫介导的细胞毒性， 中性粒细胞或补体与抗体结合， 肝细胞表面 这些研究可能在两个方面具有重要意义：第一， 对乙酰丙酮-磷脂加合物外观的测量可 为现有的用于以下标志物的测定添加了重要的附加组分： 酒精暴露 第二，由表位提供的另外的半抗原表位， 肝细胞表面的乙酰胆碱磷脂加合物可能是一种 中性粒细胞或补体结合的促成因子，导致 免疫介导的肝毒性。

The principle metabolite of ethanol, acetaldehyde, has been shown to react with amino groups on proteins and phospholipids to yield secondary N-ethylamine adducts. In the case of protein adducts formed during metabolism of ethanol, these amines have been shown to act as neoantigens and generate an immune response. Previous studies have shown a correlation between the presence in the serum of antibodies that bind to these adducts and alcohol-related hepatotoxicity. We have recently shown that some of the polyclonal IgG antibodies raised in rabbits against protein adducts of acetaldehyde cross-react with synthetic acetaldehyde-phosphatidylethanolamine adducts (N-ethyl-PE). If N-ethyl-PE adducts are formed in vivo during metabolism of alcohol, then binding of cross-reactive antibodies to these adducts exposed on the surface of hepatocytes could contribute to alcohol-related hepatotoxicity. The aims of this proposal are to determine if acetaldehyde adducts of phospholipids appear on the surface of alcohol-exposed hepatocytes and if binding of antibodies to them results in lysis of hepatocytes as a consequence of activation of neutrophils or complement. A sequence of steps is described that will determine whether acetaldehyde adducts of phospholipids are formed in vivo, measure the binding of antibodies to hepatocytes that have N-ethyl-phosphatidylethanolamine incorporated into their surface using flow cytometry, and measure the immune-mediated cytotoxicity that could result from binding of neutrophils or complement to antibodies on the hepatocyte surface. These studies may be significant in two ways: First, measurement of the appearance of acetaldehyde-phospholipid adducts may add an important additional component to existing assays for markers of alcohol exposure. Second, the additional haptenic epitopes provided by acetaldehyde-phospholipid adducts on the hepatocyte surface may be a contributing factor in binding of neutrophils or complement that results in immune-mediated hepatotoxicity.