Fetomaternal microchimerism in tissue repair and tumor development

Increased fetal microchimerism in immune and stem cell subsets in preeclampsia

“…78,79 It is currently unclear whether pluripotent FMCs are biased to distinct lineages prior to passage across the placenta, or if they acquire alternative fates in response to maternal environment. 80,81 This altered immune phenotype, as well as the presence of FMc in the stem cell population provides a potential mechanism for the inflammation which occurs during PE to have a long-lasting changes to the maternal immune system and may potentially play a role in promotion of chronic maternal disease. [81][82][83][84] Studies of larger populations and of the genetic programing of FMc are necessary to reveal the nuances in FMc phenotypes in normal and PE pregnancies.…”

“…Animal studies have demonstrated that transfer of pluripotent FMc can lead to development of functional immune cells 78,79 . It is currently unclear whether pluripotent FMCs are biased to distinct lineages prior to passage across the placenta, or if they acquire alternative fates in response to maternal environment 80,81 . This altered immune phenotype, as well as the presence of FMc in the stem cell population provides a potential mechanism for the inflammation which occurs during PE to have a long‐lasting changes to the maternal immune system and may potentially play a role in promotion of chronic maternal disease 81–84 .…”

Exploring genetic and immune underpinnings of the sexual dimorphism in tumor response to immune checkpoints inhibitors: A narrative review

“…However, this unique immune state engendered by both fetal ( Rackaityte and Halkias, 2020 ) and placental ( Murata et al., 2021 ) cues may evolve during life as chimerism ( Bianchi et al., 1996 ; Jeanty et al., 2014 ), resulting from long term persistence of fetal DNA in mothers, may constitute an underlying mechanism of the increased incidence of autoimmunity in women ( Fugazzola et al., 2011 ). Most clinical and experimental observations have suggested a rather protective action exerted by fetal microchimerism on the development of cancer, however conflicting results persist on such issue ( Sedov et al., 2022 ; Kallenbach et al., 2011 ). How immunogenic and tolerogenic pathways in women who have been pregnant are differentially informed with the advent of cancer remains unknown and represent a fascinating area of future investigations in the era of immunotherapy.…”

Adopted neoplastic cells and the consequences of their existence

“…A hint that neoplastic adoption is not limited to transplant patients comes from the studies of fetomaternal microchimerism, a condition in which cells exchanged between a woman and her child during pregnancy persist in their bodies, sometimes for decades [194][195][196]. If the fetus is a male, fetal cells can be identified in the mother's tissues by visualizing the Y chromosome, the same approach that was used to look for cell hybrids in transplant patients.…”

“…This approach has revealed that some fetal cells have properties of migratory progenitors with multilineage differentiation capacity [197,198]. Like mesenchymal stromal cells, these progenitors home to damaged organs and tumors, become morphologically "undistinguishable from the surrounding cells in terms of size and nuclear shape" [199], and begin to express antigens specific to the host tissues, whether normal or neoplastic [196,[199][200][201][202].…”