Expansion of blood CD34 positive cells: committed precursors expansion does not affect immature hematopoietic progenitors.
CD34 positive (CD34+) cells contain all hematopoietic progenitors from stem cells to committed precursors. Therefore the transplantation of purified bone marrow or blood CD34+ cells is sufficient for hematopoietic recovery after a myeloablative radiochemotherapy. Using different techniques, CD34+ progenitors can be induced to undergo terminal differentiation in a stroma-free liquid culture system in the presence of cytokines. In the present study, we have evaluated the functional potential of CD34+ blood progenitors after ex-vivo expansion cultures. CD34+ cells were isolated from 16 samples (PBSC n = 8 and Cord Blood (CB) n = 8) using either ISOLEX 50 (n=6), CEPRATE LC CD34 kit (n = 6) or MICROCELLECTOR T-25 Stem Cell kit (n = 4). CD34+ cells were cultured for seven days in the presence of 500 UI/ML of IL-1, 10 ng/ml of IL-3 and 10 ng/ml of SCF. We obtained an 8-fold expansion of nucleated cells. We observed a 59-fold expansion of GM-CSF responsive committed precursors, a 4.4-fold expansion of IL-1+IL-3+SCF+Epo responsive multilineage progenitors and a 2.2-fold expansion of the 5-FU resistant quiescent progenitors. We did not observe any significant difference in the amplification/expansion parameters between cultures initiated with CD34+ cells from PBSC or CB. Our data show that cytokine mediated ex-vivo expansion of blood CD34+ cells can produce a large number of committed precursors without affecting the compartment of the most immature progenitors. These results suggest that cytokine-mediated amplification technology could be of great interest in the autologous transplantation setting.
Bone Marrow Transplantation Laboratory, Universite Bordeaux II, France.
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S
David
A
A
Rice
I
I
Vianes
V
V
Duperray
M
M
Dupouy
J
J
Reiffers
D015704:CD4 Antigens / Q000097:blood*; D003114:Colony-Forming Units Assay; D016207:Cytokines / Q000494:pharmacology*; D004351:Drug Resistance; D005472:Fluorouracil / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000187:drug effects*; D006801:Humans; D011994:Recombinant Proteins / Q000494:pharmacology
D015704:CD4 Antigens; D016207:Cytokines; D011994:Recombinant Proteins; D005472:Fluorouracil