Sheriff Ahmed, Gaipl Udo S, Franz Sandra, Heyder Petra, Voll Reinhard E, Kalden Joachim R, Herrmann Martin
Institute for Clinical Immunology, Department of Medicine III, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany.
Cytometry A. 2004 Dec;62(2):75-80. doi: 10.1002/cyto.a.20090.
Apoptosis of neutrophil granulocytes is an important determinant of the resolution of inflammation. Apoptotic neutrophils undergo specific alterations in their receptor profiles. These alterations are likely to contribute to the characteristic functional silencing of the dying cells.
By flow cytometry and fluorescence microscopy, we analyzed the ganglioside GM1, a lipid raft marker, with respect to its surface expression on neutrophil and eosinophil granulocytes. Apoptosis was monitored by morphological changes and by the binding of annexin V-phycoerythrin (AxV-PE).
GM1, which was stained by the cholera toxin subunit B, was found only on neutrophil granulocytes; eosinophil granulocytes did not bind cholera toxin subunit B. GM1 was lost from the surfaces of neutrophils before AxV-PE binding (early apoptosis). Surprisingly, GM1 reappeared during the late stages of apoptosis, although without functional consequences. GM1 was found on the cell surface and in intracellular membranes, whereas CD16 was found only at the cell surface.
Loss of surface GM1 is a new marker for the detection of the aging of neutrophils. Its loss precedes the binding of AxV-PE of neutrophils.
中性粒细胞凋亡是炎症消退的一个重要决定因素。凋亡的中性粒细胞其受体谱会发生特定改变。这些改变可能导致死亡细胞出现典型的功能沉默。
通过流式细胞术和荧光显微镜，我们分析了脂筏标记物神经节苷脂GM1在中性粒细胞和嗜酸性粒细胞表面的表达情况。通过形态学变化和膜联蛋白V-藻红蛋白（AxV-PE）结合来监测细胞凋亡。
仅在中性粒细胞上发现了被霍乱毒素B亚基染色的GM1；嗜酸性粒细胞不结合霍乱毒素B亚基。在AxV-PE结合（早期凋亡）之前，GM1从中性粒细胞表面消失。令人惊讶的是，GM1在凋亡后期重新出现，尽管没有功能影响。GM1存在于细胞表面和细胞内膜中，而CD16仅存在于细胞表面。
表面GM1的丢失是检测中性粒细胞老化的一个新标志物。其丢失先于中性粒细胞与AxV-PE的结合。
