Ince C, Coremans J M, Ypey D L, Leijh P C, Verveen A A, van Furth R
Department of Infectious Diseases, University Hospital, Leiden, The Netherlands.
J Cell Biol. 1988 Jun;106(6):1873-8. doi: 10.1083/jcb.106.6.1873.
The present study has shown that changes in ionic channel currents accompany the phagocytosis of particles by mononuclear phagocytes. The patch-clamp technique in the cell-attached configuration was applied to human monocyte-derived macrophages to measure the activity of single transmembrane ionic channels in intact cells. During such measurements, IgG-opsonized and non-opsonized latex particles were offered for phagocytosis under continuous video-microscopical observation. Single particles were presented to the phagocytes at a membrane location some distance from that of the patch electrode. After a lag period following particle attachment, enhanced inward and outward time-variant single channel currents coinciding with particle engulfment were observed. On the basis of current-voltage characteristics and membrane potential measurements, the outward-directed channels were identified as K+ channels. Phagocytosis was also accompanied by slow transient changes in background membrane currents, probably due to changes in the membrane potential of the phagocytosing cell. Phagocytosis of IgG-coated latex particles differed from phagocytosis of uncoated or albumin-coated particles by a shorter lag time between particle attachment and the onset of enhanced ionic channel activity.
本研究表明，单核吞噬细胞吞噬颗粒时伴随着离子通道电流的变化。采用细胞贴附式膜片钳技术对人单核细胞衍生的巨噬细胞进行研究，以测量完整细胞中单个跨膜离子通道的活性。在这些测量过程中，在连续视频显微镜观察下，提供经IgG调理和未经调理的乳胶颗粒以供吞噬。将单个颗粒呈现给吞噬细胞，其位于距膜片电极一定距离的膜位置处。在颗粒附着后的延迟期后，观察到与颗粒吞噬同时出现的增强的内向和外向时变单通道电流。根据电流-电压特性和膜电位测量结果，外向通道被鉴定为钾通道。吞噬作用还伴随着背景膜电流的缓慢瞬态变化，这可能是由于吞噬细胞的膜电位变化所致。与未包被或白蛋白包被颗粒的吞噬作用相比，IgG包被乳胶颗粒的吞噬作用在颗粒附着与离子通道活性增强开始之间的延迟时间较短。
