Wegner G, Tannert C, Maretzki D, Schössler W
Biomed Biochim Acta. 1984;43(2):179-86.
The binding of 125iodine labelled human IgG to allogenic erythrocytes was studied at various ratios of free IgG per cell. At low concentrations of free IgG a high affinity binding was measured, which is with respect to its apparent association constant (2.8 x 10(13) mol-1) most likely a specific receptor binding and might indicate aged cells of those destined for elimination. At higher concentrations of free IgG the erythrocytes were coated by IgG in a non-saturable manner as reported by Grob et al. (Immunology 13, 189 (1967)). The erythrocyte-bound labelled IgG, which remained in the range from 15 to 400 molecules IgG per cell after intensive washings could not be chased by unlabelled IgG. This cell-bound IgG (high affinity binding) was increased 7-fold after complete ATP-depletion of erythrocytes and was 4 times higher after erythrocyte storage for 42 days. It appears that it is not the number of bound IgG molecules alone which is important for erythrocyte recognition by macrophages but also the arrangement of IgG molecules bound to membrane polypeptides.
研究了在不同游离IgG与细胞比例下，125碘标记的人IgG与同种异体红细胞的结合情况。在低浓度游离IgG时，检测到高亲和力结合，就其表观缔合常数（2.8×10¹³mol⁻¹）而言，这很可能是一种特异性受体结合，可能表明这些细胞是注定要被清除的衰老细胞。如Grob等人（《免疫学》13, 189 (1967)）所报道，在高浓度游离IgG时，红细胞以不饱和方式被IgG包被。经过强烈洗涤后，每个细胞结合的标记IgG分子数在15到400个之间，未标记的IgG无法将其置换。这种细胞结合的IgG（高亲和力结合）在红细胞完全耗尽ATP后增加了7倍，在红细胞储存42天后增加了4倍。看来，对于巨噬细胞识别红细胞而言，重要的不仅仅是结合的IgG分子数量，还有与膜多肽结合的IgG分子的排列方式。
