Hammer A, Dohr G
Institute of Histology and Embryology, Karl-Franzens-University, Harrachg. 21, A-8010, Graz, Austria.
J Reprod Immunol. 2000 Mar;46(2):83-90. doi: 10.1016/s0165-0378(99)00059-5.
The expression of Fas-ligand (FasL) on trophoblast cells is thought to play a role in immune regulation during human pregnancy. However, there are some discrepancies in the published data concerning the cell types expressing FasL in the placental villi. Therefore, we examined the expression of FasL on cryosections of first trimester and term placental tissue with three different anti-sera against FasL, which are in common use. By immunohistochemistry, all three anti-sera principally gave the same staining result. In the first trimester of pregnancy, villous cytotrophoblast cells underlying the syncytium, as well as all extravillous trophoblast cells of cell columns and cell islands, gave a clear, mainly membrane-located staining, whereas the syncytiotrophoblast, which forms the borderline to the maternal blood flow, only gave a spot-like reaction in distinct areas. The same result was obtained with term placental villi; however, in this tissue, the staining of the villous cytotrophoblast cells was less pronounced. From our results, we suggest that in placental villi, an important role of FasL in immune regulation is not very conclusive because this molecule is mainly expressed on trophoblast with no access to maternal blood or tissue. This is in contrast to the uterine part of the placenta, where FasL expressing trophoblast cells are in close contact with apoptotic maternal leukocytes.
滋养层细胞上Fas配体（FasL）的表达被认为在人类妊娠期间的免疫调节中发挥作用。然而，关于胎盘绒毛中表达FasL的细胞类型，已发表的数据存在一些差异。因此，我们用三种常用的抗FasL抗血清检测了早孕和足月胎盘组织冰冻切片上FasL的表达。通过免疫组织化学，所有三种抗血清主要给出相同的染色结果。在妊娠早期，合体滋养层下方的绒毛细胞滋养层细胞，以及细胞柱和细胞岛的所有绒毛外滋养层细胞，均呈现清晰的、主要位于细胞膜的染色，而形成与母体血流边界的合体滋养层仅在不同区域呈现点状反应。足月胎盘绒毛也得到了相同的结果；然而，在该组织中，绒毛细胞滋养层细胞的染色不太明显。根据我们的结果，我们认为在胎盘绒毛中，FasL在免疫调节中的重要作用不太明确，因为该分子主要表达于无法接触母体血液或组织的滋养层细胞上。这与胎盘的子宫部分形成对比，在子宫部分，表达FasL的滋养层细胞与凋亡的母体白细胞密切接触。
