Platelet-derived growth factor promotes ex vivo expansion of CD34+ cells from human cord blood and enhances long-term culture-initiating cells, non-obese diabetic/severe combined immunodeficient repopulating cells and formation of adherent cells.
Platelet-derived growth factor (PDGF) is a major mitogen for connective tissue cells. In this study, we investigated the effects and mechanism of PDGF on the ex vivo expansion of cord blood CD34+ cells. Our data demonstrated that among various cytokine combinations of thrombopoietin (TPO), interleukin 1 beta (IL-1beta), IL-3, IL-6 and Flt-3 ligand (Flt-3L), TPO + IL-6 + Flt-3L was most efficient in promoting the expansion of CD34+ cells, CD34+CD38- cells, mixed-lineage colony-forming units (CFU-GEMM) and long-term culture-initiating cells (LTC-IC) by 21.7 +/- 5.00-, 103 +/- 27.9-, 10.7 +/- 7.94- and 6.52 +/- 1.51-fold, respectively, after 12-14 d of culture. The addition of PDGF increased the yield of these early progenitors by 45.0%, 66.5%, 45.1% and 79.8% respectively. More significantly, PDGF enhanced the engraftment of human CD45+ cells and their myeloid subsets (CD33+, CD14+ cells) in non-obese diabetic (NOD)/severe-combined immunodeficient (SCID) mice. The expression of PDGF receptor (PDGFR)-beta was not detectable in fresh CD34+ cells but was upregulated after culture for 3 d. PDGF also enhanced the development of adherent cells/clusters that expressed the endothelial markers VE-cadherin and CD31. These findings suggest that PDGF is an effective cytokine for the ex vivo expansion of early stem and progenitor cells. The mechanism could be mediated by PDGFR-beta on committed CD34+ progenitor cells and/or secondary to the stimulation of autologous, stromal feeder cells.
Su
Rui Jun
RJ
Department of Paediatrics, The Chinese University of Hong Kong, 6th Floor, Prince of Wales Hospital, Shatin, N.T., Hong Kong.
Zhang
Xiao Bing
XB
Li
Karen
K
Yang
Mo
M
Li
Chi Kong
CK
Fok
Tai Fai
TF
James
Anthony Edward
AE
Pong
Henry
H
Yuen
Patrick Man Pan
PM
D000818:Animals; D018952:Antigens, CD34 / Q000097:blood*; D002448:Cell Adhesion / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D003114:Colony-Forming Units Assay; D016207:Cytokines / Q000494:pharmacology; D003921:Diabetes Mellitus, Experimental / Q000628:therapy*; D005312:Fetal Blood / Q000166:cytology; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects*; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D017479:Receptors, Platelet-Derived Growth Factor / Q000378:metabolism; D016511:Severe Combined Immunodeficiency / Q000628:therapy*; D013234:Stem Cells
D018952:Antigens, CD34; D016207:Cytokines; D010982:Platelet-Derived Growth Factor; D017479:Receptors, Platelet-Derived Growth Factor