Surface-Antigens Of Human Trophoblasts

Single cells and cell aggregates of human trophoblasts were studied by immunofluorescence and mixed haemadsorption for the presence of different surface antigens. Results indicate that fresh trophoblast cells do not express HL-A in detectable amounts but carry human chorionic gonadotropin (HCG) and Con-A receptors. Fresh cells also reacted with antisera to B 2 -microglobulin but after outgrowth to a monolayer, this molecule was detected at a low frequency from different individuals; the reactions were weak. In contrast, the outgrowth cells seemed to carry HCG. It was not possible to demonstrate any significant adsorption of maternal immunoglobulin to fresh trophoblast cells. Surface antigens of trophoblast cells in suspension were slightly redistributed by antibodies whereas the cells in aggregate showed no signs of redistribution.