Microchimerism - not all human cells in your body come from you | Thomas Kroneis | TEDxMedUniGraz

Quick Overview

Microchimerism, the presence of cells from one individual in another genetically distinct individual, is a widespread phenomenon in mammals, confirmed to be bi-directional, multi-generational, and evolutionarily conserved, with fetal cells crossing the placental barrier to reside in various maternal organs, including the brain, and even persisting across generations.

Key Points: Microchimerism is defined as the presence of cells from one individual within another genetically distinct individual, a process shown to be bi-directional across the placenta. Fetal cells (FMCs) transferred from the baby to the mother persist long-term, found in diverse maternal tissues like the brain, skin, heart, and blood, with some associated with beneficial effects like milk production and harmful effects like cancer or preeclampsia. The phenomenon is multi-generational, as demonstrated by cells from a grandchild being found in the mother's circulation years after the birth of the child. The existence of microchimerism is evolutionarily conserved across mammals, including mice, where fluorescent cells from one mouse were found to populate the tissues of another mouse. The speaker references a legal case where a mother struggled to prove paternity because DNA tests on her children's cells matched the father, but not her own cells in certain tissues, highlighting the complexity introduced by microchimerism. Fetal cells found in maternal tissues, such as neurons, are not always detrimental; some associations are considered beneficial (e.g., thermoregulation, bonding), while others are potentially harmful (e.g., cancer, autoimmune diseases).

Context: The presentation by Thomas Kroneis explores the biological phenomenon of microchimerism, which involves the exchange of cells between a mother and her fetus during pregnancy, leading to the persistence of fetal cells in the mother's body long after birth. Kroneis uses examples ranging from ancient myths like the Chimera to modern genetic testing cases and research on mice to illustrate the concept and its wide-ranging implications across various organs and generations.