Yen S H, Dickson D W, Crowe A, Butler M, Shelanski M L
Am J Pathol. 1987 Jan;126(1):81-91.
Ten monoclonal antibodies raised against Alzheimer's neurofibrillary tangles (ANTs) were characterized for reactivity with heat-stable microtubule fractions from bovine and human brain. Five of the antibodies showed very little reaction, but the other five reacted strongly with heat-stable microtubule associated proteins (MAPs). The proteins recognized by these antibodies have estimated molecular weights similar to those of known heat-stable MAPs, tau (52-68 kd) and MAP2 (200-250 kd). That the proteins are indeed tau and MAP2 is demonstrated by reaction of electroblotted proteins with antibodies raised in mouse and guinea pig against bovine brain tau and MAP2. One anti-ANT antibody reacts only with tau, two bind strongly to tau and weakly to MAP2, one recognizes both tau and MAP2 equally well, and one primarily stains MAP2. Extraction of ANT with 2% SDS does not remove tau or MAP2 epitopes from ANT, indicating that epitopes shared with heat-stable MAPs are integral components of ANT. The existence of tau epitopes in ANT is also demonstrated by immunoblotting of ANT-enriched fractions with anti-tau antibodies. Most of the material recognized by anti-tau antibodies in ANT-enriched fractions is present in large molecules excluded by 3% polyacrylamide gel upon electrophoresis. Anti-tau antibodies immunostain ANT in immunofluorescence and immunoperoxidase studies. The immunostaining can be blocked by absorption of anti-tau antibodies with purified tau proteins from bovine brain. Not all ANTs in any given tissue section or isolated Alzheimer perikarial preparations, however, are stained by anti-tau antibodies. These results are consistent with previous studies that have demonstrated heterogeneity of ANTs. Whether this heterogeneity is due to biochemical modification of MAPs or absence of MAPs in some ANTs is unknown. The significance of what appear to be shared epitopes recognized by monoclonal antibodies in tau and MAP2, and the implications this may have on the pathogenesis of ANT formation, requires further investigation.
针对阿尔茨海默病神经原纤维缠结（ANTs）产生的十种单克隆抗体，对其与来自牛脑和人脑的热稳定微管部分的反应性进行了表征。其中五种抗体反应非常微弱，但另外五种与热稳定微管相关蛋白（MAPs）强烈反应。这些抗体识别的蛋白质估计分子量与已知的热稳定MAPs、tau（52 - 68 kd）和MAP2（200 - 250 kd）相似。通过将电印迹蛋白与针对牛脑tau和MAP2在小鼠和豚鼠中产生的抗体反应，证明这些蛋白质确实是tau和MAP2。一种抗ANT抗体仅与tau反应，两种与tau强烈结合且与MAP2弱结合，一种对tau和MAP2的识别同样良好，一种主要染色MAP2。用2% SDS提取ANT不会从ANT中去除tau或MAP2表位，表明与热稳定MAPs共享的表位是ANT的组成部分。用抗tau抗体对富含ANT的部分进行免疫印迹也证明了ANT中存在tau表位。在富含ANT的部分中，抗tau抗体识别的大部分物质存在于电泳时被3%聚丙烯酰胺凝胶排除的大分子中。在免疫荧光和免疫过氧化物酶研究中，抗tau抗体对ANT进行免疫染色。这种免疫染色可以通过用来自牛脑的纯化tau蛋白吸收抗tau抗体来阻断。然而，在任何给定的组织切片或分离的阿尔茨海默病神经元胞体制剂中，并非所有的ANT都被抗tau抗体染色。这些结果与先前证明ANT异质性的研究一致。这种异质性是由于MAPs的生化修饰还是某些ANT中不存在MAPs尚不清楚。单克隆抗体识别的tau和MAP2中似乎共享的表位的意义以及这可能对ANT形成的发病机制产生的影响，需要进一步研究。
