Antczak D F, Allen W R
James A. Baker Institute for Animal Health, New York State College of Veterinary Medicine, Cornell University, Ithaca.
J Reprod Fertil Suppl. 1989;37:69-78.
There is little evidence for maternal immunological recognition of pregnancy in most species with the striking exception of the members of the genus Equus. Almost all mares make strong cytotoxic antibody responses to paternally inherited fetal antigens by Day 60 of gestation. Most of these responses are directed against antigens of the Major Histocompatibility Complex (MHC), which constitutes the primary immunogenetic barrier to successful organ transplantation. The source of fetal MHC antigens in the pregnant mare appears to be the specialized trophoblast cells of the chorionic girdle region of the developing placenta. These cells invade the endometrium between Days 36 and 38 after ovulation to form the endometrial cups. The progenitor girdle cells express high levels of paternal MHC antigens, while the non-invasive trophoblast cells of the allantochorion and the differentiated trophoblast cells in the mature endometrial cups do not. This expression of MHC antigens by the chorionic girdle cells is unusual for a trophoblast tissue, and differs from most forms of trophoblast studied in other species. The maternal anti-fetal antibody responses of equine pregnancy do not adversely affect fetal development, nor are they required for successful pregnancy. However, it is possible that fetal loss of an immunological nature could occur in rare cases when the immunoregulatory mechanisms of pregnancy break down.
在大多数物种中，几乎没有证据表明母体对妊娠存在免疫识别，马属动物是显著的例外。几乎所有母马在妊娠第60天时都会对父系遗传的胎儿抗原产生强烈的细胞毒性抗体反应。这些反应大多针对主要组织相容性复合体（MHC）的抗原，而MHC构成了成功进行器官移植的主要免疫遗传障碍。妊娠母马体内胎儿MHC抗原的来源似乎是发育中胎盘绒毛带区域的特化滋养层细胞。这些细胞在排卵后第36至38天侵入子宫内膜，形成子宫内膜杯。绒毛带祖细胞表达高水平的父系MHC抗原，而尿囊绒毛膜的非侵入性滋养层细胞和成熟子宫内膜杯中的分化滋养层细胞则不表达。绒毛带细胞对MHC抗原的这种表达在滋养层组织中是不寻常的，并且与在其他物种中研究的大多数滋养层形式不同。马妊娠时母体的抗胎儿抗体反应不会对胎儿发育产生不利影响，成功妊娠也不需要这些反应。然而，当妊娠的免疫调节机制失效时，在极少数情况下可能会发生免疫性胎儿丢失。
