Biological implications of bi-directional fetomaternal cell traffic: a summary of a National Institute of Child Health and Human Development-sponsored conference

Abstract

Bi-directional fetomaternal trafficking of cells and nucleic acids during pregnancy is now well established, through the use of molecular techniques including conventional and real-time polymerase chain reaction, as well as fluorescence in situ hybridization. In addition, human leukocyte antigen (HLA) is deposited in the skin of pregnant women. Fetomaternal trafficking is increased in some complications of pregnancy, such as pre-eclampsia, polyhydramnios, polymorphic eruption of pregnancy, preterm labor and specific fetal chromosome aneuploidies. Maternal cells and nucleic acids have been documented in umbilical cord blood and in autopsy tissue of non-transfused neonates. Fetal cells persist postpartum and may be associated with the development of disorders such as scleroderma, lichen planus, lupus and thyroid disease. The extent of fetomaternal trafficking may be affected by three generational HLA relationships. Thus, the consequences of pregnancy extend beyond gestation.

Concise Review: Recent Advances on the Significance of Stem Cells in Tissue Regeneration and Cancer Therapies

“…On the other hand, it is interesting to note that a reciprocal fetomaternal trafficking of cells and nucleic acids has also been shown through the placental barrier during pregnancy, which might contribute to tissue repair mechanisms in different maternal organs and the growing fetus [60, 61]. In fact, the cells from the growing fetus appear to be able to cross over the placenta and enter the mother's bloodstream and vice versa; the maternal cells can also pass into fetal circulation and persist into adult life, a phenomenon known as microchimerism.…”

“…In fact, the cells from the growing fetus appear to be able to cross over the placenta and enter the mother's bloodstream and vice versa; the maternal cells can also pass into fetal circulation and persist into adult life, a phenomenon known as microchimerism. Hence, the fetal cells that are transferred to the mother during gestation can migrate to different damaged peripheral tissues, such as the liver and skin, or can cross the blood‐brain barrier to enter damaged areas of the brain, where they actively contribute to the mother's tissue repair by generating mature cell progenitors [60, –62]. More surprisingly, a small number of functional fetal cells with stem‐cell‐like properties, designated pregnancy‐associated progenitor cells, appear also to persist in blood and tissues after pregnancy, and thereby continue to assume their protective role in tissue repair or contribute to certain pathophysiologies [60, 62].…”

Placental lesions associated with maternal underperfusion are more frequent in early-onset than in late-onset preeclampsia

“…This specific pregnancy disorder can be the result of multiple mechanisms of disease [9,10,13,16,20,21,25,32–36,42,43,46,47,53,56,57,59,64–66,70,78,80–82,84,87,88,91,102,105,111,112,116,120,123,129,134,136,144,154], is adaptive in nature [2,15,44,96,97,113,135] and has a long subclinical phase [19,22,63,67,68,98,100,122, 125,140,145]. Due to its syndromic nature, several attempts have been made to classify patients with PE into distinct subgroups in order to improve un derstanding of its pathophysiology [148–150,153], predict maternal/fetal complications [4,27,89,124,126] and to develop individualized preventive or therapeutic interventions [11,23,128,138].…”

Human Amnion Mesenchyme Harbors Cells with Allogeneic T-Cell Suppression and Stimulation Capabilities

“…Proposed explanations are the anatomical barrier between the mother and the fetus formed by the placenta, the immunological inertness of the mother, and the antigenic immaturity of the fetus [38]. However, several studies have indicated that the fetal placental barrier may be less inert or impervious than previously envisioned, with evidence presented for cellular trafficking in both directions across the fetal/maternal interface [39, –41]. In addition, it is now clear that the maternal immune system is not anergic to all fetal tissues, since it can respond to and eliminate fetal cells that enter the maternal circulation [40, 42].…”