AMYLOID ENHANCING FACTOR: ITS NATURE AND FUNCTION

淀粉样蛋白增强因子(AEF)是淀粉样蛋白形成过程中除增加血清淀粉样前体蛋白外的重要因子之一。主要研究结果如下：1.从淀粉样变性小鼠的脏器中提取AEF，发现脾中AEF活性最高。从粗提物中提取的抗AEF抗血清的组织化学研究表明，AEF定位于脾和外周血中的中性粒细胞。电子显微镜显示AEF不分布在颗粒中，而是分布在中性粒细胞的胞浆中。此外，通过添加脱粒剂，将收集的中性粒细胞分为颗粒组分和颗粒外组分，并对小鼠进行了试验研究，只有颗粒组分具有AEF活性。用DEAE离子交换柱和反相高效液相色谱法从经淀粉样变刺激处理的脾和外周血中性粒细胞中纯化AEF。AEF活性在DEAE柱上用0.17M生理盐水洗脱，保留时间为23min。在高效液相色谱上。SDS-PAGE显示单一条带，大小约为15 KDa。根据气相色谱的结果，AEF是一种重达15kDa的糖蛋白。在含AEF的培养液中培养的Kupffer细胞有许多细胞突起和肿胀，在电子显微镜下可见细胞器的变性。这些结果表明，AEF可能对巨噬细胞造成损伤，然后淀粉样前体蛋白随着淀粉样变刺激而增加，不能被降解的淀粉样前体蛋白被聚合并转变为纤维。

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.