Baerlocher G M, Schlappritzi E, Straub P W, Reinhart W H
Department of Internal Medicine, University of Bern, Switzerland.
Br J Haematol. 1994 Mar;86(3):629-34. doi: 10.1111/j.1365-2141.1994.tb04796.x.
Erythrocytes with decreased deformability are known to be rapidly removed from the circulation by splenic macrophages. The exact mechanism is, however, not well understood. We have analysed the phagocytosis of less-deformable erythrocytes by macrophages in vitro. Human monocytes/macrophages were isolated from peripheral blood and cultured for a total time of 6 h at 37 degrees C with 5% CO2. Autologous erythrocytes of the rhesus positive donor were rigidified by heat treatment (47 degrees C for 1 h). The change in erythrocyte deformability was assessed with a filter aspiration technique; the membrane elastic modulus was found to be increased about 2.5-fold. For controls, untreated erythrocytes and erythrocytes incubated with anti-RhD-antibodies were prepared. The rate of phagocytosis during 2 h at 37 degrees C and 5% CO2 was 0.74 +/- 0.59 (erythrocytes per monocyte/macrophage) for controls, 3.58 +/- 2.72 for anti-RhD-loaded erythrocytes and 0.82 +/- 0.74 for heat-treated erythrocytes, respectively. We conclude that decreased erythrocytes deformability does not cause an increased rate of phagocytosis by monocytes/macrophages compared to normally deformable erythrocytes in our in vitro model. This suggests that the preferential removal of rigid cells in vivo is probably not a specific process, but is due to the increased splenic transit time of rigid erythrocytes and hence longer interaction time between erythrocytes and phagocytes.
已知可变形性降低的红细胞会被脾脏巨噬细胞迅速从循环中清除。然而，确切机制尚不清楚。我们在体外分析了巨噬细胞对可变形性较低的红细胞的吞噬作用。从外周血中分离出人单核细胞/巨噬细胞，并在37℃、5%二氧化碳条件下共培养6小时。恒河猴阳性供体的自体红细胞通过热处理（47℃ 1小时）使其变硬。用滤过抽吸技术评估红细胞可变形性的变化；发现膜弹性模量增加了约2.5倍。作为对照，制备了未处理的红细胞和与抗RhD抗体孵育的红细胞。在37℃、5%二氧化碳条件下2小时内的吞噬率，对照组为0.74±0.59（每个单核细胞/巨噬细胞吞噬的红细胞数），抗RhD负载的红细胞为3.58±2.72，热处理的红细胞为0.82±0.74。我们得出结论，在我们的体外模型中，与正常可变形的红细胞相比，红细胞可变形性降低不会导致单核细胞/巨噬细胞吞噬率增加。这表明体内刚性细胞的优先清除可能不是一个特定过程，而是由于刚性红细胞在脾脏中的转运时间增加，从而导致红细胞与吞噬细胞之间的相互作用时间延长。
