Immunological mechanism on the generation of alcoholic liver diseases

为探讨酒精性肝病发生的免疫学机制，从乙醛诱导抗原性的角度检测枯否细胞(肝脏中的巨噬细胞)的作用，并检测酒精对肝细胞表面1类MHC的影响。用胶原酶灌流分离枯否细胞和按比重分离的肝细胞与乙醛孵育。将这些细胞与细胞毒性T淋巴细胞混合，对抗乙醛修饰的同源细胞(CTL)。仅有Kupffer细胞裂解，其表面存在Class1 MHC。这一结果表明了1类MHC在免疫反应中的重要性以及正常肝细胞上缺乏1类MHC。然后，从诱导1类MHC的角度来检查乙醇给药。饮酒后12h用细胞毒性T淋巴细胞法检测第1类MHC。1类Mhc升高ac…而乙醛表位在乙醇灌胃的小鼠肝细胞表面未检测到。然后对两组小鼠进行等量酒精配对喂养和无酒精配对喂养。饲养至28d，胶原酶灌注法分离肝细胞。不含乙醇的小鼠肝细胞表面无1类MHC或乙醛表位。用乙醇喂养的小鼠肝细胞显示1类MHC水平升高，但没有显示CTL所显示的乙醛加合物表位。接下来，给小鼠腹腔注射三聚氰胺，以提高血清乙醛水平。用三聚氰胺或不用三聚氰胺处理的小鼠进行配对喂养，肝细胞检查同上。经三聚氰胺处理的小鼠肝细胞仅表现出较高的1类MHC水平，因此，可能需要长期给予乙醇喂养和/或先前的病毒感染等治疗，以在肝细胞上形成乙醛蛋白加合物。这种猜测将在我们单位用同样的程序进行核查。较少

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