Human stem-progenitor cells from neonatal cord blood have greater hematopoietic expansion capacity than those from mobilized adult blood.
OBJECTIVE
In this study we compared the hematopoietic capacity of CD34+ cell preparations from neonatal cord blood (CB) vs adult mobilized peripheral blood (PBSC) before and after ex vivo culture.


METHODS
CD34+ cell preparations purified from CB or PBSC were cultured in serum-free medium containing FKT: FLT-3 ligand (FL), KIT ligand (KL), and thrombopoietin (TPO).


RESULTS
After 1-4 weeks ex vivo culture, CB CD34+ cell preparations had greatly increased numbers of total cells, CD34+ cells, and colony-forming cells (CFC). In contrast, ex vivo-cultured PBSC CD34+ cell preparations generated far less in vitro assessed hematopoietic capacity. Nonobese diabetic severe combined immunodeficient mouse (NOD/SCID) engrafting potential (SEP) was maintained in ex vivo-cultured CB CD34+ cell preparations, whereas ex vivo-cultured PBSC lost SEP. CB CD34+ cells continued to proliferate throughout 3 weeks ex vivo, whereas after 1 week, no additional cell divisions were detected in PBSC CD34+ cells. After 3 weeks in culture, the average CB CD34+ cell had divided more than 5 times, as compared to only 2 times for the average PBSC CD34+ cell.


CONCLUSIONS
CB CD34+ cell preparations generated massively increased in vitro assessed hematopoietic capacity and maintained SEP during 1- to 4-week ex vivo cultures. In contrast, ex vivo-cultured PBSC CD34+ cell preparations generated far less in vitro assessed hematopoietic capacity and decreased SEP. The differences in the in vitro proliferative indices of membrane dye-labeled CD34+ cells from CB vs PBSC correlated with these functional differences.
Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Vivek M
VM
Tanavde
Matthew T
MT
Malehorn
Rachata
R
Lumkul
Zhigang
Z
Gao
John
J
Wingard
Elizabeth S
ES
Garrett
Curt I
CI
Civin
D000328:Adult; D000818:Animals; D018952:Antigens, CD34 / Q000032:analysis; D015415:Biomarkers; D001773:Blood Cells / Q000166:cytology* / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D019070:Cell Lineage; D002469:Cell Separation; D002470:Cell Survival; D002478:Cells, Cultured / Q000166:cytology / Q000187:drug effects; D003114:Colony-Forming Units Assay; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D019650:Hematopoietic Stem Cell Mobilization; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D007231:Infant, Newborn; D008565:Membrane Proteins / Q000494:pharmacology; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D013047:Specific Pathogen-Free Organisms; D019089:Stem Cell Factor / Q000494:pharmacology; D013926:Thrombopoietin / Q000494:pharmacology; D014183:Transplantation, Heterologous
D018952:Antigens, CD34; D015415:Biomarkers; D016895:Culture Media, Serum-Free; D008565:Membrane Proteins; D019089:Stem Cell Factor; C084881:flt3 ligand protein; D013926:Thrombopoietin