[Are CD133 and CD271 useful in positive selection to enrich umbilical cord blood mesenchymal stem cells?].

ABSTRACT

It is well accepted that umbilical cord blood has been a source for mesenchymal stem cells. However, there was less success in culturing these cells by using traditional method. Lots of studies showed that CD271 (low affinity nerve growth factor receptor LNGFR) and CD133 could be used to positive sort of bone marrow-derived mesenchymal stem cells (MSC) in recent years. The present study was designed to explore whether the method of positive sorting of umbilical cord blood-derived MSC (UCB-MSC) was effective by using CD271 and CD133 immunomagnetic beads. The ability of forming CFU-F and differentiation capacity of the four kinds of cells, namely CD271+, CD271-, CD133+ and CD133- were analysed. The results indicated that the purities of immunomagnetically selected CD271+ and CD133+ cells were (87.58±0.48)% and (89.89±8.10)% respectively. More than 99% of CD271+ and CD133+ cells expressed CD34 and CD45, the markers of hematopoietic stem cells. CFU-F assay showed that CD271+ and CD133+ cells could not form any CFU-F and only few single fibroblast-like cells could be found in the dishes. However, part of the negative samples (27%) could form CFU-F. Phenotype of cells (passage 3) isolated by the two methods was the same, that was CD34-, CD45-, CD14-, CD29+, CD44+, CD73+, CD105+ and CD90+. They both had osteogenic and adipogenic differentiation potential. It is concluded that nearly all the CD271 and CD133 positive cells are hematopoietic cells, MSC can be effectively collected by negative selection with immunomagnetic beads against CD271 and CD133.