Ugele B, Hecht J, Kuss E
I. Frauenklinik, Klinikum Innenstadt, Ludwig-Maximilians-Universität, Maistrasse 11, München, 80337, Federal Republic of Germany.
Exp Cell Res. 1998 Oct 10;244(1):137-46. doi: 10.1006/excr.1998.4161.
Trophoblast cells, dispersed by trypsin digestion of human term placental villi and purified on Percoll gradient, were maintained in serum-containing medium as monolayer cultures up to 7 days. The initially mononucleated cells, probably cytotrophoblasts, differentiated in culture within 90 h to multinucleated syncytiotrophoblast-like cells. The enigmatic binding of human immunoglobulin G (hIgG) to these cells was studied and compared to the well-known binding of hIgG to cultured human monocytes. Binding of hIgG to cultured trophoblasts at 4 degreesC reached steady state by 0.5-1 h, increased about two- to threefold after 90 h in culture and was linear throughout all concentrations tested (0.00067-132 microM). Fc fragments and even F(ab')2 fragments were found to bind to a similar extent to trophoblasts as the complete hIgG molecules. In contrast, in experiments with cultured monocytes, saturation of hIgG binding could be demonstrated. The binding of complete hIgG molecules and of Fc fragments to monocytes was similar whereas binding of F(ab')2 fragments to monocytes was significantly lower. Our results suggest that, despite morphological and at least partially functional differentiation of trophoblast cells in primary culture, no measurable amounts of functional Fc receptor for monomeric hIgG was expressed.
通过胰蛋白酶消化人足月胎盘绒毛分散并在Percoll梯度上纯化的滋养层细胞，在含血清培养基中作为单层培养物维持长达7天。最初的单核细胞，可能是细胞滋养层细胞，在培养90小时内分化为多核合体滋养层样细胞。研究了人免疫球蛋白G（hIgG）与这些细胞的神秘结合，并将其与hIgG与培养的人单核细胞的已知结合进行比较。hIgG在4℃下与培养的滋养层细胞的结合在0.5 - 1小时达到稳态，培养90小时后增加约两到三倍，并且在所有测试浓度（0.00067 - 132 microM）范围内呈线性。发现Fc片段甚至F(ab')2片段与完整的hIgG分子一样，与滋养层细胞的结合程度相似。相比之下，在培养的单核细胞实验中，可以证明hIgG结合的饱和。完整的hIgG分子和Fc片段与单核细胞的结合相似，而F(ab')2片段与单核细胞的结合明显较低。我们的结果表明，尽管原代培养中的滋养层细胞在形态上和至少部分功能上发生了分化，但未表达可测量量的单体hIgG功能性Fc受体。
