AMYLOID ENHANCING FACTOR: ITS NATURE AND FUNCTION

淀粉样蛋白增强因子（AEF）是淀粉样蛋白生成过程中除血清中淀粉样前体蛋白增加外的一个重要因素。我们从淀粉样变性小鼠的器官中提取AEF，并在脾脏中发现最高的AEF活性。用AEF粗品制备的抗AEF抗血清进行组织化学研究，发现AEF定位于脾和外周血的中性粒细胞上，电镜观察发现AEF不分布于中性粒细胞的颗粒中，而分布于中性粒细胞的胞浆中。此外，收集的中性粒细胞被分离成颗粒和颗粒外部分，加入脱粒剂，只有颗粒部分在小鼠试验研究中具有AEF活性.用DEAE离子交换柱和反相HPLC从用淀粉样变性刺激物处理的脾和外周血的中性粒细胞中纯化AEF。AEF活性在DEAE柱上用0.17M盐水洗脱的级分中，在HPLC上保留时间为23分钟的峰中。SDS-聚丙烯酰胺凝胶电泳显示单一条带，分子量约为15 KDa。考虑到气相色谱AEF的结果，是一种重15 kDa的糖蛋白。在含AEF的培养液中培养的枯否细胞突起增多，细胞肿胀，电镜下细胞器变性，提示AEF可损伤巨噬细胞，使淀粉样前体蛋白增多，不能降解，聚合成纤维。

Amyloid enhancing factor (AEF) is one of the factors in amyloidogenesis, besides the increase of amyloid precursor protein in a serum.We present the following results;1. We extracted AEF from organs of amyloidotic mice and the highest AEF activity was found in a spleen. On a histochemical study using anti-AEF antiserum, derived from the crude AEF, AEF is localized on neutrophils of spleen and peripheral blood.Electron microscopy reveals that AEF is not distributed in granules but in the cytosol of a neutrophil. Furthermore collected neutrophils are separated into granular and extra-granular fractions, with adding a degranulating agent, and only the granular fraction has AEF activity on a trial study on mice.2. AEF is purified with a DEAE ion exchange column and a reverse phase HPLC from neutrophils of spleen and peripheral blood treated with amyloidotic stimuli. AEF activity is in a fraction eluted with 0.17M saline on DEAE column and in a peak of retention time 23 min. on HPLC. SDS-page gives single band, about 15 KDa. considering with a result from a Gas-chromatography AEF is a glycoprotein weighing 15 KDa.3. Kupffer cells, cultured in the media with AEF, have many cell processes and swell, and on electron microscopic observation they indicate degenerations of organelle.These results suggest that AEF may cause damage on macrophages and then amyloid precursor protein increased with amyloidotic stimuli, which is not able to be degradated, is polymerized and changes into fibrils.