Effect of stem cell factor (SCF), Flt3 Ligand (FL) and thrombopoietin (TPO) on ex vivo expansion of mononuclear cells derived from umbilical cord blood under hypoxic conditions / 中华器官移植杂志

ABSTRACT

Objective To explore the effect of stem cell factor (SCF), Flt3 Ligand (FL) and Thrombopoietin (TPO) on the expansion of the mononuclear cells derived from umbilical cord blood ex vivo under hypoxic conditions.Method Human fresh CB mononuclear cells were isolated and cultured with different combinations of cytokine for 7 days under normoxic or hypoxic conditions (3 ％ O2).At day 0 and 7 of culture, total nucleated cells (TNC), CD34+ , CD34+ CXCR4+ , CD34+ CD49d+ and CD34+ CD62L+ cells were assayed by flow cytometry, and colony forming unit (CFU) was determined.The experiment was divided into four groups group A (cells were cultured in single mononuclear cells under normoxic conditions);group B (cells were cultured in single mononuclear cells under hypoxic conditions);group C (cells were cultured with SCF, FL and TPO under normoxic conditions);group D (cells were cultured with SCF, FL and TPO under hypoxic conditions).Result At 7th day of culture, TNC, CD34+ cells and CFU expansion were significantly increased in groups B, C and D, and the expansion effect in group D was superior to that in groups B and C, but there was no significant difference between groups B and C (P＞0.05).At 7th day of culture, the expression levels of CD49d, CD62L and CXCR4 on expanded CD34 + cells were significantly reduced in group A as compared with those at day 0, and those in groups B, C and D were significantly increased as compared with those in group A, those in group D were significantly higher than in group D than in groups B and C (P＜0.05),but there was no significant difference between groups B and C (P＞ 0.05).Conclusion Hypoxic conditions could enhance the expansion and expression of CD49d, CD62L and CXCR4 of mononuclear cells derived from umbilical cord blood with SCF, FL and TPO.