Amniotic fluid as a novel source of mesenchymal stem cells for therapeutic transplantation

Human mesenchymal stem cells (MSCs) are multipotent stem cells, able to differentiate into multiple mesenchymal lineages. 1-3 Previously, we have shown that human fetal lung-derived MSCs enhance the engraftment of human umbilical cord blood (UCB)derived CD34 hematopoietic cells in nonobese diabetic-severe combined immunodeficiency mice. 1 Here we show that secondtrimester amniotic fluid is an abundant source of fetal MSCs that exhibit a phenotype and multilineage differentiation potential similar to that of postnatal bone marrow (BM)-derived MSCs. We suggest that amniotic fluid is an attractive source of MSCs for cotransplantation in conjunction with UCB-derived hematopoietic stem cells.