Preliminary characterization of the surface staining of placental derived adherent cells: a potential new source of stroma for umbilical cord blood (ucb) expansion
Stromal-based ex-vivo expansion of UCB provides a potential method to overcome the limited graft cell dose for adult recipients. The benefit of stromal-based expansion compared to cytokine-based expansion is maintenance of primitive stem and progenitor cells during the culture period. However, UCB does not produce autologous stroma during the expansion process. Since the placenta is a known source of growth factors that support hematopoiesis, we sought to develop placenta! derived adherent cells as a novel source of stroma for UCB hematopoiesis. This source of supporting cells may provide an autologous "feeder layer" for UCB ex-vivo expansion. Placental derived adherent cells can be cultured from cryopreserved placental tissue obtained at the time of UCB collection. We have demonstrated that placental derived adherent cells support UCB expansion. Using a Biotin/Avidin based staining procedure the cells have been stained in-situ for surface expression of mesenchymal stem cell markers (SH2, SH3, SH4), hematopoietic progenitor cell markers (CD45), adhesion molecules (PECAM), HLA- Class I (HLA-ABC), endothelial cell markers (von Willebrand Factor) and tissue specific stains (P-Cadherin, (X smooth muscle actin, and vimentin). Placental derived adherent cells (N=3), mesenchymal stem cells (N=2), human umbilical vein endothelial cells (N=l), and human umbilical vein smooth muscle cells (N=l) were stained for surface expression of these markers. For mesenchymal stem cells and placental derived adherent cells, there appears to be no difference in the surface staining characteristics of cells that have been passaged from 1 -3 times and cells that have been cultured, frozen, and replated. As expected, the placental derived adherent cells are heterogeneous in phenotype, and clusters or individual cells stained positively for SH2, SH3, SH4, and a smooth muscle actin. The placental derived adherent cells do not express CD45, PECAM, or von Willebrand Factor, suggesting that they do not contain hematopoietic or endothelial cells. Placenta] derived adherent cells, and the other cell types stained did not express HLA-ABC. This definition of placental derived adherent cells surface markers is an important first step in the characterization of this novel source of adherent cells for stromal-based expansion of umbilical cord blood.
Jaroscak, J; Smith, T; Haynesworth, S; Laughlin, MJ; Kurtzberg, J; Gerson, SL
Volume / Issue
International Standard Serial Number (ISSN)