Kawanami S, Mori S, Kikuchi M, Shirakusa T
First Department of Internal Medicine, Fukuoka University, School of Medicine, Japan.
Fukuoka Igaku Zasshi. 1999 Jun;90(6):286-94.
We studied the immunohistochemical localization of Fas and nicotinic acetylcholine receptor (nAChR) in the human thymus with myasthenia gravis (MG). Thymuses were obtained from thirteen patients with MG, (thymic hyperplasia 8; thymoma 5) and six normal controls. Antibodies against Fas, nAChR protein isolated from fetal calf thymus (nAChR-FCT), CD3, CD4, and CD8 were used. In both hyperplastic thymus and controls, Fas antigen was found in medullary epithelial cells especially in those around Hassall's corpuscle, in subcapsular epithelial cells, and partially in the cortex. There were no apparent differences between myasthenic thymus and the controls. In the thymic medulla the anti-nAChR-FCT antibody showed a similar staining pattern to the antibody against Fas. The nAChR and the Fas were suggested to be present in the same cell. Then six thymomas were double immunostained with antibodies against Fas and nAChR-FCT. A part of neoplastic epithelial cells were double positive for both Fas and nAChR. The present results show the first observation on the colocalization of the Fas and nAChR in thymic epithelial cells. These antigens were supposed to work on triggering mechanism of autoimmunity in MG.
我们研究了重症肌无力（MG）患者人胸腺中Fas和烟碱型乙酰胆碱受体（nAChR）的免疫组化定位。胸腺取自13例MG患者（胸腺增生8例；胸腺瘤5例）和6例正常对照者。使用了抗Fas抗体、从胎牛胸腺分离的nAChR蛋白（nAChR-FCT）、CD3、CD4和CD8抗体。在增生性胸腺和对照中，Fas抗原见于髓质上皮细胞，尤其是哈氏小体周围的细胞、被膜下上皮细胞以及部分皮质。重症肌无力患者的胸腺与对照之间无明显差异。在胸腺髓质中，抗nAChR-FCT抗体显示出与抗Fas抗体相似的染色模式。提示nAChR和Fas存在于同一细胞中。然后用抗Fas和nAChR-FCT抗体对6例胸腺瘤进行双重免疫染色。部分肿瘤上皮细胞Fas和nAChR均呈双阳性。目前的结果首次观察到Fas和nAChR在胸腺上皮细胞中共定位。这些抗原被认为在MG自身免疫的触发机制中起作用。
