Medof M E, Prince G M
Immunology. 1983 Sep;50(1):11-8.
Experimental antigen-antibody complexes (Ag-Ab) were incubated at 37 degrees with human red blood cells (RBC) suspended in autologous normal serum and the reaction stopped after progressively increasing times. Bound antigen-antibody-complement complexes (Ag-Ab-C) were eluted from C3b receptors and the eluted Ag-Ab-C re-incubated with different blood cell types suspended in serum, or centrifuged (along with unbound Ag-Ab-C found in the serum) through 20-50% sucrose gradients. Ag-Ab-C recovered from C3b receptors shortly after initial binding to RBC bound efficiently to other RBC, polymorphonuclear and mononuclear cells, and sedimented rapidly. Ag-Ab-C simultaneously present in the serum sedimented with a similar velocity. Ag-Ab-C recovered at a subsequent time during RBC interaction bound less well to each blood cell type, and sedimented less rapidly. Decreased amounts of rapidly sedimenting Ag-Ab-C were present in the serum. Ag-Ab-C recovered from C3b receptors at a still later time in the course of RBC interaction bound poorly to each cell type, and sedimented slowly. Increased amounts of slowly sedimenting Ag-Ab-C were found in the serum. These findings indicate that alterations in properties of immune complexes can occur while they are associated with C3b receptors on RBC membrane in solid phase.
将实验性抗原 - 抗体复合物（Ag - Ab）与悬浮于自体正常血清中的人红细胞（RBC）在37摄氏度下孵育，并在逐渐增加的时间后终止反应。从C3b受体上洗脱结合的抗原 - 抗体 - 补体复合物（Ag - Ab - C），然后将洗脱的Ag - Ab - C与悬浮于血清中的不同血细胞类型重新孵育，或（连同血清中未结合的Ag - Ab - C）通过20 - 50%的蔗糖梯度离心。最初与RBC结合后不久从C3b受体回收的Ag - Ab - C能有效地结合到其他RBC、多形核细胞和单核细胞上，并迅速沉降。同时存在于血清中的Ag - Ab - C以相似的速度沉降。在RBC相互作用的后续时间回收的Ag - Ab - C与每种血细胞类型的结合较差，沉降也较慢。血清中快速沉降的Ag - Ab - C数量减少。在RBC相互作用过程中更晚时间从C3b受体回收的Ag - Ab - C与每种细胞类型的结合都很差，沉降缓慢。血清中发现缓慢沉降的Ag - Ab - C数量增加。这些发现表明，免疫复合物与固相RBC膜上的C3b受体结合时，其性质可能会发生改变。
