[Functional defect of partial homing receptor on human cord blood hematopoietic stem/progenitor cells]

This study was aimed to investigate the function defect of partial homing receptor on cord blood hematopoietic stem cells (CBHSC) and explore efficacy and feasibility of intervention in vitro. The expression and activity of active groups in P, E-selectin ligands on CD34+ cells from cord blood, bone marrow and peripheral blood were detected by flow cytometry; meanwhile the expression of active groups in selectin ligands on CD34+ cells treated by fucosyl transferase in vitro was determined by flow cytometry. The results indicated that the expression levels of CD26 on the surface of stem/progenitor cells (CD34+) from cord blood, bone marrow and peripheral blood were (7.62+/-0.63)%, (6.35+/-0.89)% and (6.18+/-0.91)% (p>0.05) respectively. And the activities of CD26 of the three sources of stem cells were 67.15 U/1000 cells (1 U=1 pmol/min), 26.85 U/1000 cells and 20.95 U/1000 cells respectively, in which the activity of CD26 on surface of CD34+ from cord blood was significantly higher than that from other both sources (p<0.01). The expression levels of P-selectin ligand on the stem/progenitor cells three kinds were (83.46+/-6.33)%, (15.65+/-0.89)% and (80.17+/-6.85)%, and the expression levels of E-selectin ligand on stem/progenitor cells of three kinds were (25.31+/-1.03)%, (26.34+/-0.89)% and (29.79+/-1.78)% respectively. The expression of E-selectin ligand on the surface of cord blood stem/progenitor cell CD34+ increased from (25.31+/-1.03)% to (63.23+/-1.08)% after glycosylation engineering. It is concluded that there is no significant difference of the expression of CD26 between the three sources of stem/progenitor cells, but the activity of CD26 in cord blood was obviously higher than that in bone marrow and peripheral blood. The expression of P-selectin ligand on bone marrow stem/progenitor cell was lower than that on stem cells of cord blood and peripheral blood. Glycosylation engineering can promote and elevate the expression of E-selectin ligand on the surface of CD34+ cells from cord blood.