Kávai M, Rasmussen J M, Baatrup G, Zsindely A, Svehag S E
Third Department of Medicine, University Medical School, Debrecen, Hungary.
Scand J Immunol. 1988 Jul;28(1):123-8. doi: 10.1111/j.1365-3083.1988.tb02423.x.
The binding of soluble complement-reacted IgM immune complexes (IC) to erythrocyte (E) C3b-C4b receptors (CR1) and the incorporation of C3b-iC3b into solid phase IgM-IC was investigated. The optimal binding of liquid phase IgM-IC to E-CR1 was obtained with IC formed at moderate antibody excess, but the binding was low (2-3%) when compared to the binding of the corresponding IgG-IC (50-60%). Solid phase IC were prepared by coating microwells with heat-aggregated bovine serum albumin (BSA) followed by incubation with rabbit IgM anti-BSA antibody. The IC were reacted with human serum at 37 degrees C. The binding of C3b-iC3b was determined by use of biotinylated F(ab')2 antibodies to C3b-C3c and avidin-coupled alkaline phosphatase. The incorporation of C3b-iC3b into solid-phase IgM-IC increased when increasing amounts of IgM antibody were reacted with the antigen. The binding reaction was slow, reaching a maximum after about 2 h at 37 degrees C. The binding of C3b-iC3b to the IgM-IC was remarkably inefficient when compared to the incorporation into IgG-IC reacted with the same amounts of BSA-precipitating antibody.
研究了可溶性补体反应性IgM免疫复合物（IC）与红细胞（E）C3b - C4b受体（CR1）的结合以及C3b - iC3b掺入固相IgM - IC的情况。液相IgM - IC与E - CR1的最佳结合是在抗体适度过量时形成的IC，但与相应IgG - IC的结合（50 - 60%）相比，其结合率较低（2 - 3%）。通过用热聚集牛血清白蛋白（BSA）包被微孔，然后与兔抗BSA IgM抗体孵育来制备固相IC。IC在37℃与人血清反应。使用生物素化的F(ab')2抗C3b - C3c抗体和抗生物素蛋白偶联碱性磷酸酶来测定C3b - iC3b的结合。当与抗原反应的IgM抗体量增加时，C3b - iC3b掺入固相IgM - IC的量增加。结合反应缓慢，在37℃约2小时后达到最大值。与掺入相同量BSA沉淀抗体反应的IgG - IC相比，C3b - iC3b与IgM - IC的结合效率明显较低。
