Duclos A J, Haddad E K, Baines M G
Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada.
Am J Reprod Immunol. 1995 May;33(5):354-66. doi: 10.1111/j.1600-0897.1995.tb00904.x.
Even though our knowledge of the phenomenon at play at the fetoplacental interface has greatly advanced during the past years, a complete understanding of the reasons why the developing embryo is not rejected by maternal immune effector cells remains largely unknown.
We have used immunohistochemistry with the macrophage-specific markers F4/80 and MHC II to study the relationship between decidual infiltration and resorption in murine models of embryo loss between days 6 and 10 of gestation.
Analysis of day 8 CBA/J x DBA/2 pregnancies has revealed 2 distinct populations of embryos. The majority (69.4%) expressed low levels of F4/80+ cells, but a minority (30.6%) expressed much higher level of the macrophage marker. In FBA/J x BALB/c, most embryos (91.7%) expressed low numbers of F4/80+ cells. As earlier experiments established that products of activated macrophages (TNF-alpha and nitric oxide) were implicated in embryo loss in this model, the activation status of the F4/80+ macrophages was assessed through the cell surface expression of MHC II. Again, a similar association was established: 30.6% of the CBA/J x DBA/2 embryos were infiltrated by significantly more MHC II+ cells than the control CBA/J x BALB/c mating. Finally, when coordinate expression of F4/80, MHC II and CD11b was assessed, it was found that an embryo significantly infiltrated by cells bearing one of the 3 markers was also heavily infiltrated by cells bearing the 2 other markers.
This study has shown that the augmented infiltration of the deciduum with maternal macrophages is an early event which precedes spontaneous abortion of the early embryo.
尽管在过去几年里，我们对胎盘界面所涉及现象的了解有了很大进展，但对于发育中的胚胎为何未被母体免疫效应细胞排斥的原因，仍在很大程度上不清楚。
我们使用针对巨噬细胞特异性标志物F4/80和MHC II的免疫组织化学方法，来研究妊娠第6至10天小鼠胚胎丢失模型中蜕膜浸润与吸收之间的关系。
对妊娠第8天的CBA/J×DBA/2小鼠进行分析，发现有两种不同类型的胚胎。大多数（69.4%）胚胎表达低水平的F4/80+细胞，但少数（30.6%）胚胎表达的巨噬细胞标志物水平要高得多。在FBA/J×BALB/c小鼠中，大多数胚胎（91.7%）表达少量的F4/80+细胞。由于早期实验表明，在该模型中活化巨噬细胞的产物（肿瘤坏死因子-α和一氧化氮）与胚胎丢失有关，因此通过MHC II的细胞表面表达来评估F4/80+巨噬细胞的活化状态。同样，也建立了类似的关联：与对照的CBA/J×BALB/c交配相比，30.6%的CBA/J×DBA/2胚胎被显著更多的MHC II+细胞浸润。最后，当评估F4/80、MHC II和CD11b的协同表达时，发现被携带这三种标志物之一的细胞显著浸润的胚胎，也被携带其他两种标志物的细胞大量浸润。
本研究表明，母体巨噬细胞对蜕膜浸润的增加是早期胚胎自然流产之前的一个早期事件。
