Amoroso E C, Perry J S
Philos Trans R Soc Lond B Biol Sci. 1975 Jul 17;271(912):343-61. doi: 10.1098/rstb.1975.0057.
In mammalian pregnancy the trophoblast normally constitutes an uninterrupted boundary of foetal tissue in immediate contact with maternal tissue, including blood in some species, and is the decisive immunological barrier to rejection of the foetus as an allograft. The ability of the trophoblast to function as a barrier evidently results from its capacity to resist immunological attack by either alloantibody or alloimmune cells and to prevent immunocompetent cells from reaching and damaging the foetus but, as yet, there is no general agreement regarding the means by which it exercises these functions. In view of the dramatic hormonal changes that occur during pregnancy and the undisputed involvement of trophoblast in these endocrine events, the possibility exists of an interaction between the hormones of pregnancy and the immunological phenomena. The present account furnishes evidence that endocrine activity at the maternal surface of the trophoblast, the presumptive site of the immunological frontier between foetus and mother, may be a factor in its local survival at implantation. The placental hormones so far known that are capable of blocking the antigen receptor sites of the mother's lymphocytes and thus preventing the latter from reacting with the foetal antigens are the glycoprotein, human chorionic gonadotrophin (HCG) and the polypeptide hormone, human chorionic somatomammotrophin (HCS) or human placental lactogen (HPL), both of which are specific to the human placenta. The origin of these hormones, their spatial distribution and their probable interaction with placental steroid hormones are discussed. It is argued that the place of highest concentration of these hormones is on the surface of the syncytial microvilli and the adjacent caviolae of the apical plasma membrane, as well as on the surfaces of the persisting cytotrophoblastic cells of the basal plate (cytotrophoblastic shell), the cell islands and the septa-precisely where the immunological challenge of the foetal allograft to the maternal host occurs. An explanation is offered for the continuing production of the voluminous quantities of these hormones during human pregnancy.
在哺乳动物妊娠过程中，滋养层通常构成与母体组织直接接触的胎儿组织的连续边界，在某些物种中还包括血液，并且是作为同种异体移植物的胎儿排斥反应的决定性免疫屏障。滋养层作为屏障发挥功能的能力显然源于其抵抗同种抗体或同种免疫细胞免疫攻击以及防止免疫活性细胞到达并损害胎儿的能力，但是，关于其行使这些功能的方式尚未达成普遍共识。鉴于妊娠期间发生的剧烈激素变化以及滋养层无可争议地参与这些内分泌事件，妊娠激素与免疫现象之间存在相互作用的可能性。本报告提供的证据表明，滋养层母体表面的内分泌活动，即胎儿与母亲之间免疫前沿的假定部位，可能是其在着床时局部存活的一个因素。迄今为止已知的能够阻断母亲淋巴细胞抗原受体位点从而防止后者与胎儿抗原发生反应的胎盘激素是糖蛋白人绒毛膜促性腺激素（HCG）和多肽激素人绒毛膜生长催乳素（HCS）或人胎盘催乳素（HPL），这两种激素都是人类胎盘特有的。讨论了这些激素的起源、它们的空间分布以及它们与胎盘甾体激素可能的相互作用。有人认为，这些激素浓度最高的部位是合体微绒毛表面、顶端质膜相邻的小窝以及基底板（细胞滋养层壳）、细胞岛和隔膜中持续存在的细胞滋养层细胞表面——正是胎儿同种异体移植物对母体宿主产生免疫挑战的部位。还对人类妊娠期间这些激素持续大量产生的现象给出了解释。
