During pregnancy, mother and child exchange cells. These can persist for years in the mother’s body and influence her state of health.
In Greek mythology, the chimera is a fantastic creature with the head of a lion, the body of a goat and the tail of a serpent. Millennia later, medicine recovered this cruel monster to characterize an organism made up of several cells with different genetic origins.
Today, we are all potentially pipe dreams. Blood transfusion, organ transplant, transform us into a mythical creature. But the most common event in the world is pregnancy. Indeed, during these 9 months, the mother and the fetus exchange gases, nutrients, but also cells. After crossing the placenta, the fetal cells migrate into the mother’s body. Nestled in the lungs, intestines or even the skin, some escape the immune system and persist for a very long time, sometimes decades after the birth of the child.
Their fate and their effects on the mother’s organism are the subject of lively debate in the scientific world. That’s why a research team from Arizona State University looked at the available studies on fetal microchimerism. She publishes its results in the early edition of BioEssays.
Protective …
“Fetal cells can act like stem cells and transform into epithelial, heart or liver cells,” explains Amy Boddy, a researcher in the Department of Psychology at Arizona State University and head of the work. These cells are therefore very dynamic and can play an important role in the mother’s body. They can even migrate to the brain and differentiate into neurons. “
Several studies have shown that these cells are able to cooperate with different tissues and promote healing. Indeed, we find these cells at the level of the wounds, in particular at the level of the incision for the cesarean section. Some observations also suggest their role in tissue repair of the heart or liver. As with cell therapy, these multipotent cells are capable of becoming cardiomyocytes or hepatocytes depending on the environment in which they are found to replace defective or dead cells.
CREDIT: Written by Athena Aktipis, Amy Boddy, Joe Caspermeyer, Angelo Fortunato, Richard Harth, Carlo Maley and Melissa Wilson Sayres, Arizona State University. Produced by Indivio Media, Indivio.com
… or harmful
But sometimes, without knowing yet why, these cells can turn against their host and promote the appearance of autoimmune diseases. In fact, recognized as foreign by the mother’s immune system, these cells are destroyed, which helps to generate an inflammatory reaction. This process could partly explain why rheumatoid arthritis is 3 times more common in women than in men, note the authors. Fetal cells are also mentioned in the occurrence of lupus or biliary cirrhosis.
Their responsibility is also mentioned in certain cancers. In the case of breast cancer, their role is complex. Fetal cells are generally found in low amounts in women with breast cancer compared to healthy women, suggesting a protective role. However, there is some evidence that these microchimeric cells are associated with an increased risk of breast cancer in the years following pregnancy. In mothers with lung cancer, “we find significantly more microchemical cells in diseased tissue than in healthy tissue,” notes Laetitia Albano, nephrologist at the CHU de Nice. in a document from the Nephrology Society.
A complex puzzle
Fetal cells are therefore one piece of a complex and still poorly understood puzzle. And to complicate matters even more, subsequent pregnancies also bring their share of microchimeric cells, potentially introducing rivalries between maternal and fetal cells, but also between different fetal cells, the authors point out.
“If future work confirms these different relationships, it could transform the treatment and prevention of several diseases affecting women, and particularly new mothers,” comments Athena Aktipis, co-author of the study. But for that, the methods of detecting these cells will have to be improved in order to be more precise.
.
