Veerhuis R, Krol M C, van Es L A, Daha M R
Clin Immunol Immunopathol. 1986 Dec;41(3):379-91. doi: 10.1016/0090-1229(86)90008-5.
In this study the similarities and differences in kinetics and site of clearance of particulate immune complexes and soluble aggregates of IgG (AIgG) were compared in rats. The rate of clearance of both antibody-coated erythrocytes (EA) and AIgG was dependent on the number of IgG molecules per EA or AIgG. Both probes were rapidly taken up by the liver. Whereas a minor part of the AIgG returned to the circulation as TCA-soluble breakdown products, a substantial part of the injected EA returned to the circulation as intact cells after 4 min. This rebound mechanism was shown to be complement (C)-dependent. Immediately after injection the injected EA bound C3 on their surface, whereafter the number of C3-bearing cells in the circulation rapidly decreased (T1/2 7.2 min). In C-depleted rats relatively more EA were taken up by the spleen than by the liver, in comparison with EA injected into normal rats (liver/spleen ratio in C-depleted rats 0.4 +/- 0.1; in normal rats 2.1 +/- 0.4). When C3 was bound and inactivated by preincubation of EA in vitro, a similar shift from liver to spleen (liver/spleen ratio 0.4 +/- 0.1) was observed. It is suggested that when the hepatic C receptors do not participate, the splenic Fc receptors become relatively more important in the clearance of EA from the circulation.
在本研究中，对大鼠体内颗粒性免疫复合物和IgG可溶性聚集体（AIgG）的动力学及清除部位的异同进行了比较。抗体包被红细胞（EA）和AIgG的清除率均取决于每个EA或AIgG上IgG分子的数量。两种探针均被肝脏迅速摄取。虽然一小部分AIgG以三氯乙酸可溶性分解产物的形式返回循环，但注射的EA有很大一部分在4分钟后以完整细胞的形式返回循环。这种反弹机制被证明是补体（C）依赖性的。注射后，注射的EA立即在其表面结合C3，此后循环中携带C3的细胞数量迅速减少（半衰期7.2分钟）。与注射到正常大鼠体内的EA相比，在补体缺乏的大鼠中，脾脏摄取的EA相对较多（补体缺乏大鼠的肝/脾比率为0.4±0.1；正常大鼠为2.1±0.4）。当通过体外预孵育使EA结合并灭活C3时，观察到类似的从肝脏到脾脏的转移（肝/脾比率为0.4±0.1）。有人认为，当肝脏C受体不参与时，脾脏Fc受体在从循环中清除EA方面变得相对更重要。
