Werthamer S, Govindaraj S, Amaral L
J Clin Invest. 1976 Apr;57(4):1000-8. doi: 10.1172/JCI108341.
The syncytiotrophoblastic cells of the human placenta contain a cytoplasmic protein recognized by fluorescein-labeled transcortin-specific antibody. Purification of this protein from human placenta, by those methods employed for the purification of human plasma transcortin, yielded a protein that exhibited antigenic and biochemical similarity to plasma transcortin. Placental transcortin differs from plasma transcortin in that it has a smaller sedimentation coefficient (3S vs 3.75S) and binds cortisol less strongly. This purified protein is able to block the phytohemagglutinin response of maternal lymphocytes even more than serum transcortin. It is postulated that the biological role may be that of inhibiting the maternal cell-mediated immune response to the presence of the antigenic conceptus.
人胎盘的合体滋养层细胞含有一种可被荧光素标记的皮质素转运蛋白特异性抗体识别的细胞质蛋白。采用用于纯化人血浆皮质素转运蛋白的方法从人胎盘中纯化该蛋白，得到一种在抗原性和生化特性上与血浆皮质素转运蛋白相似的蛋白。胎盘皮质素转运蛋白与血浆皮质素转运蛋白的不同之处在于，它的沉降系数较小（3S对3.75S），与皮质醇的结合力较弱。这种纯化蛋白比血清皮质素转运蛋白更能阻断母体淋巴细胞的植物血凝素反应。据推测，其生物学作用可能是抑制母体对具有抗原性的孕体存在的细胞介导免疫反应。
