Yokoyama H
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
Arukoru Kenkyuto Yakubutsu Ison. 1993 Dec;28(6):483-96.
Acetaldehyde, the first metabolite of ethanol, is capable to bind various proteins followed by the formation of acetaldehyde adducts. This condensate is supposed to act as a neoantigen. We have recently demonstrated the appearance of acetaldehyde adducts in liver of experimental animals after chronic ethanol treatment, and we produced an experimental hepatitis in guinea pig by immunization with acetaldehyde adducts and treatment with free access to ethanol. However the structure of acetaldehyde adducts and its characteristics are still vague. To elucidate the binding site of anti-adducts antibody against the epitope on adducts, we established a cell line of hybridoma producing monoclonal antibody. This monoclonal antibody recognized protein condensate modified with high concentration of acetaldehyde (1-10 mM) but not those modified with low concentration of it (20-200 microM), whereas the polyclonal antibody produced by conventional method recognized both of them. Using the affinity-purified adducts by monoclonal or polyclonal antibody-liganded column, we examined the antibody titers by ELISA. The elevation of antibody titer was more specific in chronic alcoholics, especially in patients with hepatic inflammatory change, when antibody was measured against the adducts purified by monoclonal antibody than against the adduct purified by polyclonal antibody. Namely, there exist different types of antibody according to the concentration of acetaldehyde to form the adducts. The concentration of acetaldehyde is thought to be much greater in the liver of alcoholics compared to the patient with non alcoholic liver disease. Actually we have immunohistochemically detected the adduct related to high concentration of acetaldehyde in the liver specimen of alcoholics. In conclusion, the appearance of adduct related to high concentration of acetaldehyde and the acquisition of immunity against it appear to be a characteristic feature in alcoholics with hepatic inflammation. Therefore, evaluation of circulating antibodies against protein epitope related to high concentration of acetaldehyde is helpful to know conditions of such types of liver disease seen in alcoholics.
乙醛是乙醇的首个代谢产物，能够与多种蛋白质结合，随后形成乙醛加合物。这种缩合物被认为可作为一种新抗原。我们最近已证明，在对实验动物进行慢性乙醇处理后，其肝脏中会出现乙醛加合物，并且我们通过用乙醛加合物免疫并让豚鼠自由摄取乙醇的方式，在豚鼠身上引发了实验性肝炎。然而，乙醛加合物的结构及其特征仍不明确。为了阐明抗加合物抗体针对加合物上抗原决定簇的结合位点，我们建立了一个产生单克隆抗体的杂交瘤细胞系。这种单克隆抗体识别用高浓度乙醛（1 - 10 mM）修饰的蛋白质缩合物，但不识别用低浓度乙醛（20 - 200 microM）修饰的蛋白质缩合物，而通过传统方法产生的多克隆抗体则能识别这两者。使用通过单克隆或多克隆抗体配体柱亲和纯化的加合物，我们通过酶联免疫吸附测定法检测了抗体效价。当检测针对通过单克隆抗体纯化的加合物的抗体时，抗体效价的升高在慢性酗酒者中更具特异性，尤其是在有肝脏炎症改变的患者中，这一特异性高于检测针对通过多克隆抗体纯化的加合物的抗体时。也就是说，根据形成加合物的乙醛浓度存在不同类型的抗体。与非酒精性肝病患者相比，酗酒者肝脏中的乙醛浓度被认为要高得多。实际上，我们已经通过免疫组织化学方法在酗酒者的肝脏标本中检测到了与高浓度乙醛相关的加合物。总之，与高浓度乙醛相关的加合物的出现以及针对它的免疫反应的获得似乎是患有肝脏炎症的酗酒者的一个特征。因此，评估针对与高浓度乙醛相关的蛋白质抗原决定簇的循环抗体，有助于了解酗酒者中此类肝病的状况。
