Immunological mechanism on the generation of alcoholic liver diseases

为了探讨酒精性肝病发生的免疫学机制，我们从乙醛诱导抗原性的角度考察了库普弗细胞（肝脏巨噬细胞）的作用，并在给药后检测了肝细胞表面的1类MHC。将胶原酶灌注分离的Kupffer细胞和肝细胞按比重分离，用乙醛孵育。将这些细胞与抗乙醛修饰的同基因细胞（CTL）的细胞毒T淋巴细胞混合。只有Kupffer细胞被裂解，原因是其表面存在1类MHC。这一结果表明1类MHC在免疫反应中的重要性，而正常肝细胞缺乏1类MHC。然后，从诱导1类MHC的角度检查乙醇给药。饮酒后12小时用细胞毒T淋巴细胞法检测1类MHC。1类MHC水平升高与饲喂乙醇的时间和乙醇消耗量有关，但在饲喂乙醇的小鼠肝细胞表面未检测到乙醛表位。然后对两组小鼠分别进行乙醇或不乙醇配对喂养。小鼠喂养至28 d，采用胶原酶灌注法分离肝细胞。无乙醇小鼠肝细胞表面没有1类MHC或乙醛表位。乙醇喂养小鼠肝细胞显示1类MHC水平升高，但没有CTL显示的乙醛加合物表位。然后，给小鼠腹腔注射氰胺以提高血清乙醛水平。分别对加氰胺和不加氰胺的小鼠进行配对喂养，肝细胞检查同上。用氰胺处理的小鼠肝细胞仅显示1类MHC水平升高。因此，长期用乙醇喂养和/或先前用病毒感染等治疗可能是必要的，以在肝细胞上建立乙醛蛋白加合物。这种猜测将在我们单位以同样的程序进行检查。少

To investigate immunological mechanism on the generation of alcoholic liver diseases, the role of Kupffer cell (macrophage in the liver) was checked from the point of the induction of antigenicity of acetaldehyde, and class 1 MHC on the surface of hepatocyte was checked after administration of alcohol.Kupffer cell and hepatocyte those were isolated by collagenase perfusion and separated according to the specific gravity were incubated with acetaldehyde. Those cells were mixed with cytotoxic T lymphocyte against acetaldehyde-modified syngeneic cells (CTL). Only Kupffer cells were lysed with the reason of the existence of Class 1 MHC on its surface. This result showed the importance of class 1 MHC in immunological reaction and the lack of class 1 MHC on normal hepatocyte.Then, ethanol administration was checked from the point of induction of class 1 MHC. Class 1 MHC was detected by cytotoxic T lymphocyte method shortly 12 hours after alcohol drinking. The level of class 1 MHC elevated ac … More cording to the time up to 14 days and the comsumed volume of ethanol, but acetaldehyde epitope wasn't detected on the surface of hepatocyte from mice that were fed with ethanol. Then pair feeding with or without ethanol was done to two groups of mice isocalolically. Mice were fed up to 28 days, and hepatocytes were isolated by the method of collagenase infusion. Hepatocytes from mice fed without ethanol showed no class 1 MHC or acetaldehyde epitope on its surface. Hepatocytes from mice fed with ethanol revealed the elevated level of class 1 MHC, but no acetaldehyde adduct epitope which would be showed by CTL. Next, the cyanamide was given to mice intraperitoneally to elevate the serum level of acetaldehyde. Pair feeding was done to mice treated with or without cyanamide, and hepatocytes were checked just as same as above. Hepatocytes from mice treated with cyanamide showed only the elevated level of class 1 MHC.So, long term feeding with ethanol and/or previous treatment with such as viral infection might be necessary to build acetaldehyde protein adduct on hepatocytes. Such speculation will be checked with same procedure in our unit. Less