Effect of different cytokines on the proliferation of CD_(34)~+ hematopoietic cells in cord blood*

[Objective] To investigate the proliferative effect of different cytokines on the CD34+ hematopoietic cells in umbilical cord blood. [Methods] In this study, a serum-free, stroma-free medium for hematopoietic stem cells proliferation was systematically developed. CD34+ cells isolated with the EasySep human CD34+ positive selection system from umbilical cord blood were cultured in vitro with different cytokines for 14 days to evaluate proliferative potential. Group A: SCF+FL+TPO, group B: SCF+FL+TPO+IL-3, group C: SCF+FL+TPO+G-CSF. [Results] The number of CD34+ cells reached peak at the 7th day with no significant difference among 3 groups. While addition of the growth factors SCF, TPO, FL and IL-3 to serum-free media did allow high proliferation of hematopoietic cells with the most total nuclear cells after 7 and 14 days of culture. CFU-G and CFU-GEMM formed after plantation of 7 d-proliferated cord blood hematopoietic cells into methylcellulose media. [Conclusions] These data indicate that SCF, FL and TPO can be used to efficiently proliferate hematopoietic progenitors from human umbilical cord blood.