Amouzadeh H R, Pohl L R
Molecular and Cellular Toxicology Section, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1760, USA.
Hepatology. 1995 Sep;22(3):936-43.
In this study we have investigated the mechanism of the processing of trifluoroacetylated liver microsomal protein antigens associated with halothane hepatitis to learn how the immune system might come in contact with these proteins to form antibodies directed against them. Rats were treated with halothane and parenchymal (PC) and non-parenchymal cells (NPC) were isolated 16 hours later. Immunoblotting of the cell lysates with antisera directed against the trifluoroacetyl hapten showed the presence of high levels of trifluoroacetylated proteins in parenchymal cells, whereas none of these proteins were detected in endothelial or Kupffer cells that were isolated by centrifugal elutriation. The half-lives of 100-, 82-, 80-, 63-, 59-, 58-, and 57-kd trifluoroacetylated and native carrier proteins of the trifluoroacetyl hapten in cultures of rat primary parenchymal cells were approximately 1 day. The turnovers of all of these trifluoroacetylated proteins, except for that of the trifluoroacetylated 100-kd protein, were inhibited by treatment of the cells with ammonium chloride, leupeptin, 4-(2-aminoethyl)-benzenesulfonyl fluoride, or 3-methyl-adenine (3-MA). These results indicate that, in liver, the major source of the formation of trifluoroacetylated antigens associated with halothane hepatitis is the parenchymal cells, It appears that most of the trifluoroacetylated antigens and possibly the native carrier protein of the trifluoroacetyl haptens are transferred from the endoplasmic reticulum (ER) to an acidic compartment of PCs, where they are enzymatically degraded. The processing of the trifluoroacetylated proteins by this pathway may be a protective mechanism that prevents these covalently altered proteins from inducing an antibody response in most patients who are administered halothane.
在本研究中，我们调查了与氟烷性肝炎相关的三氟乙酰化肝微粒体蛋白抗原的加工机制，以了解免疫系统如何接触这些蛋白从而形成针对它们的抗体。用氟烷处理大鼠，16小时后分离实质细胞（PC）和非实质细胞（NPC）。用针对三氟乙酰半抗原的抗血清对细胞裂解物进行免疫印迹分析，结果显示实质细胞中存在高水平的三氟乙酰化蛋白，而通过离心淘析分离的内皮细胞或库普弗细胞中未检测到这些蛋白。在大鼠原代实质细胞培养物中，三氟乙酰半抗原的100kd、82kd、80kd、63kd、59kd、58kd和57kd三氟乙酰化及天然载体蛋白的半衰期约为1天。除三氟乙酰化的100kd蛋白外，所有这些三氟乙酰化蛋白的周转均受到氯化铵、亮抑酶肽、4-（2-氨基乙基）苯磺酰氟或3-甲基腺嘌呤（3-MA）处理细胞的抑制。这些结果表明，在肝脏中，与氟烷性肝炎相关的三氟乙酰化抗原形成的主要来源是实质细胞。似乎大多数三氟乙酰化抗原以及可能的三氟乙酰半抗原的天然载体蛋白从内质网（ER）转移到实质细胞的酸性区室，在那里它们被酶降解。通过该途径对三氟乙酰化蛋白的加工可能是一种保护机制，可防止这些共价改变的蛋白在大多数接受氟烷治疗的患者中诱导抗体反应。
