Trowsdale John, Betz Alexander G
Department of Pathology, Immunology Division, University of Cambridge, Cambridge CB2 1QP, UK.
Nat Immunol. 2006 Mar;7(3):241-6. doi: 10.1038/ni1317.
The evolutionary adaptation in mammals that allows implantation of their embryos in the mother's womb creates an immunological problem. Although it ensures optimal nourishment and protection of the fetus throughout its early development, intimate contact with the mother's uterine tissue makes the fetus a potential target for her immune system. As half the fetal genes are derived from the father, the developing embryo and placenta must be considered a 'semi-allograft'. Such a mismatched organ transplant would be readily rejected without powerful immune suppression. During pregnancy, however, the semi-allogeneic fetus is protected from assault by the maternal immune system over an extended period of time. The mother's immune system seems to recognize the fetus as 'temporary self'. How this feat is managed is key to understanding immunological tolerance and intervention in treating disease.
哺乳动物的进化适应性使其胚胎能够植入母体子宫，这引发了一个免疫学问题。尽管这确保了胎儿在早期发育过程中能获得最佳营养和保护，但与母体子宫组织的密切接触使胎儿成为母体免疫系统的潜在攻击目标。由于胎儿一半的基因来自父亲，发育中的胚胎和胎盘必须被视为“半同种异体移植物”。如果没有强大的免疫抑制，这种不匹配的器官移植很容易被排斥。然而，在怀孕期间，半同种异体胎儿在很长一段时间内受到母体免疫系统的保护。母体免疫系统似乎将胎儿识别为“暂时的自身”。如何实现这一壮举是理解免疫耐受以及疾病治疗干预的关键。
