ABSTRACT
Peripheral blood-derived endothelial progenitor cells (EPCs) have been extensively studied in mammals but the isolation and characterization of EPCs in avian species have not been reported. In this study, chicken peripheral blood mononuclear cells (PBMNCs) were cultured under conditions favoring endothelial-specific differentiation for 2 weeks. One heterogeneous cell population dominated by spindle-shaped cells (early EPCs) and one homogeneous cell population exhibiting cobblestone-like morphology (endothelial outgrowth cells, EOCs) appeared sequentially. Quantitative polymerase chain reaction (PCR) showed the expression of several progenitor and endothelial cell markers such as CD133, VEGFR-2 and CD31 in both cell populations. However, CD34, another progenitor marker, was undetectable in either freshly isolated PBMNCs or cultured cells. The endothelial phenotype of the EOCs was further identified by acetylated low-density lipoprotein/lectin double staining, and in vitro tube formation. Collectively, these data demonstrate that chicken EPCs can be isolated and cultured from PBMNCs and suggest that EPCs obtained from peripheral blood may originate mainly from the CD34- subpopulation.
