Authors:
Shannon L. McKinney-Freeman, Olaia Naveiras, Frank Yates, Sabine Loewer, Marsha Philitas, Matthew Curran, Peter J. Park, and George Q. Daley
Summary:
Surface antigens on Hematopoietic Stem Cells (HSC) enable prospective isolation and characterization. Here we compare the cell surface phenotype of hematopoietic repopulating cells from murine yolk sac, aorta-gonad-mesonephros, placenta, fetal liver and bone marrow with that of HSCs derived from the in vitro differentiation of murine Embryonic Stem Cells (ESC-HSC). Whereas c-Kit marks all HSC populations, CD41, CD45, CD34 and CD150 were developmentally regulated: the earliest embryonic HSCs express CD41 and CD34 and lack CD45 and CD150, while more mature HSCs lack CD41 and CD34 and express CD45 and CD150. ESC-HSC express CD41 and CD150, lack CD34, and are heterogeneous for CD45. Finally, although CD48 was absent from all in vivo HSC examined, ESC-HSC were heterogeneous for the expression of this molecule. This unique phenotype signifies a developmentally immature population of cells with features of both primitive and mature HSC. The prospective fractionation of ESC-HSC will facilitate studies of HSC maturation essential for normal functional engraftment in irradiated adults.
Source:
Blood; (05/06/09)