Garred P, Michaelsen T E, Aase A, Mollnes T E
Institute of Immunology and Rheumatology, National Hospital, University of Oslo, Norway.
J Immunol. 1990 Jan 1;144(1):198-203.
The binding of the C components C1q, C4, C3, the terminal C5b-9 complement complex (TCC) and S protein to immune complexes was studied. The hapten 5-iodo-4-hydroxy-3-nitrophenacetyl (NIP) conjugated to BSA was adsorbed to polystyrene plates and reacted with a human IgG3-mouse chimeric anti-NIP antibody. After addition of serum a dose-dependent binding of C1q, C4, C3, and TCC to the immune complexes was found. An increase in the amount of NIP-BSA was associated with an increase in the binding of TCC and a decrease in the binding of S-protein. After addition of soluble NIP only 4 to 6% of the anti-NIP antibody remained bound to the Ag. C1q showed diminished binding after addition of NIP, whereas C4, C3, and TCC quantitatively remained bound to the Ag. Binding of TCC to the immune complexes was also found in an alternative assay, in which the anti-NIP antibody was adsorbed to the solid phase before NIP-BSA and an additional layer of anti-NIP antibody were added. The supernatants from the solid phase assay were tested for C3 activation and formation of the fluid phase TCC (SC5b-9). Activation of the C3 was reflected in the fluid phase by a dose-dependent increase in C3 activation products. This was not seen for TCC despite increased binding to the solid phase.
研究了补体成分C1q、C4、C3、终末补体复合物C5b - 9（TCC）和S蛋白与免疫复合物的结合情况。将与牛血清白蛋白（BSA）偶联的半抗原5 - 碘 - 4 - 羟基 - 3 - 硝基苯乙酰（NIP）吸附到聚苯乙烯平板上，并与一种人IgG3 - 小鼠嵌合抗NIP抗体反应。加入血清后，发现C1q、C4、C3和TCC与免疫复合物呈剂量依赖性结合。NIP - BSA量的增加与TCC结合增加及S蛋白结合减少相关。加入可溶性NIP后，仅4%至6%的抗NIP抗体仍与抗原结合。加入NIP后，C1q的结合减少，而C4、C3和TCC在数量上仍与抗原结合。在另一种检测方法中也发现了TCC与免疫复合物的结合，即在NIP - BSA和额外一层抗NIP抗体加入之前，先将抗NIP抗体吸附到固相上。对固相检测的上清液进行C3活化和液相TCC（SC5b - 9）形成的检测。C3活化产物在液相中的剂量依赖性增加反映了C3的活化。尽管TCC与固相的结合增加，但在液相中未观察到这种情况。
