Evaluation of the effect of cryopreservation on ex vivo expansion of hematopoietic progenitors from cord blood.
In previous studies, we identified a cytokine cocktail including thrombopoietin, Flt-3 ligand, interleukin (IL)-6 and IL-11 in serum-free medium, suitable to induce significant and sustained ex vivo expansion of primitive hematopoietic stem cells (HSCs) from cord blood (CB) for up to 10 weeks. The aim of the present study was to evaluate the effects of cryopreservation on ex vivo expansion of HSCs and their committed progenitors. CD34+ cells were purified from CB units, each of which was processed in part as such and in part as cryopreserved and thawed, then expanded for 5 weeks in serum-free medium with the cytokine cocktail described above. We determined the number of nucleated cells (NC), CD34+, CD34+/38(-)/33(-), CD34+/61+, CD61+ cells and the clonogenic potential. After 2 weeks the median fold expansion of NC, CD34+ and CD34+/38(-)/33(-) cells was around two log both with fresh and cryopreserved CB and the expansion continued similarly until week 5. Our data suggest that this serum free protocol induces similar ex vivo expansion of HSCs and their committed progenitors from both fresh and cryopreserved CB. Our findings can be useful in view of clinical applications, since CB used for transplantation is stored in the cryopreserved state.
Lazzari
L
L
Milano Cord Blood Bank, Centro Trasfusionale e di Immunologia dei Trapianti, IRCCS Ospedale Maggiore, Via Francesco Sforza 35, 20122 Milan, Italy.
Lucchi
S
S
Montemurro
T
T
Porretti
L
L
Lopa
R
R
Rebulla
P
P
Sirchia
G
G
D001793:Blood Preservation; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured / Q000166:cytology / Q000187:drug effects; D003114:Colony-Forming Units Assay; D015925:Cryopreservation; D016895:Culture Media, Serum-Free; D005312:Fetal Blood / Q000166:cytology*; D006098:Granulocytes / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D016130:Immunophenotyping; D007231:Infant, Newborn; D017370:Interleukin-11 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008533:Megakaryocytes / Q000166:cytology; D008565:Membrane Proteins / Q000494:pharmacology; D013926:Thrombopoietin / Q000494:pharmacology
D016895:Culture Media, Serum-Free; D017370:Interleukin-11; D015850:Interleukin-6; D008565:Membrane Proteins; C084881:flt3 ligand protein; D013926:Thrombopoietin