Horgan C, Burge J, Crawford L, Taylor R P
J Immunol. 1984 Oct;133(4):2079-84.
[3H]dsDNA/anti-DNA immune complexes (IC) formed, fixed complement, and bound rapidly to red blood cells (RBC) in whole blood (less than 5 min), but were released from the cells more slowly. The rate of release was dependent on both the antibody:DNA ratio and the m.w. of the DNA in the complex. For example, complexes formed with high m.w. DNA (6 X 10(6) daltons) were released more slowly (t1/2 = 60 min) than complexes formed with lower m.w. DNA (2 to 6 X 10(5) daltons, t1/2 = 15 to 20 min). The [3H]dsDNA/anti-DNA complexes, which were released from the cells as intact antigen/antibody/complement complexes, did not rebind to RBC, but did bind to Raji cells and could be precipitated by monoclonal antibody to C3d. When these released IC (RIC) containing high m.w. DNA were incubated with additional anti-DNA antibody and fresh complement, they rebound to RBC. However, RIC containing lower m.w. DNA (5 X 10(5) daltons) did not rebind to RBC under the same conditions. These data suggest that IC containing high m.w. DNA bind to and remain bound to RBC more effectively than IC containing lower m.w. DNA, and thus may be more easily cleared from the circulation by the RBC IC clearance mechanism. Thus, the size of the DNA in the IC may be a significant factor in the pathogenicity of DNA/anti-DNA complexes in SLE.
[3H]双链DNA/抗DNA免疫复合物（IC）形成后，固定补体，并在全血中迅速与红细胞（RBC）结合（不到5分钟），但从细胞中释放的速度较慢。释放速度取决于抗体与DNA的比例以及复合物中DNA的分子量。例如，与高分子量DNA（6×10⁶道尔顿）形成的复合物释放得比与低分子量DNA（2至6×10⁵道尔顿）形成的复合物更慢（t1/2 = 60分钟）（t1/2 = 15至20分钟）。从细胞中作为完整抗原/抗体/补体复合物释放的[3H]双链DNA/抗DNA复合物不会重新结合到RBC上，但会结合到Raji细胞上，并可被抗C3d单克隆抗体沉淀。当这些含有高分子量DNA的释放的IC（RIC）与额外的抗DNA抗体和新鲜补体一起孵育时，它们会重新结合到RBC上。然而，在相同条件下，含有低分子量DNA（5×10⁵道尔顿）的RIC不会重新结合到RBC上。这些数据表明，含有高分子量DNA的IC比含有低分子量DNA的IC更有效地结合并保持与RBC的结合，因此可能更容易通过RBC IC清除机制从循环中清除。因此，IC中DNA的大小可能是SLE中DNA/抗DNA复合物致病性的一个重要因素。
