Propagation of pure fetal and maternal mesenchymal stromal cells from terminal chorionic villi of human term placenta.

Long term propagation of human fetal mesenchymal stromal cells (MSC) in vitro has proven elusive due to limited availability of fetal tissue sources and lack of appropriate methodologies. Here, we have demonstrated the presence of fetal and maternal cells within the tips of terminal chorionic villi (TCV) of normal human term placenta, and we have exploited inherent differences in the adhesive and migratory properties of maternal vs. fetal cells, to establish pure MSC cultures of both cell types. The origin and purity of each culture was confirmed by X-Y chromosome-specific fluorescence in situ hybridization (FISH) and short tandem repeat (STR) genotyping. This is the first demonstration of fetal and maternal cells in the TCV of human term placenta and also of deriving pure fetal MSC cultures from them. The concomitant availability of pure cultures of adult and fetal MSC from one tissue provides a good system to compare genetic and epigenetic differences between adult and fetal MSCs; and also to generate new models of cell based therapies in regenerative medicine.