Umbilical cord blood as a rich source of immature hematopoietic stem cells.
To investigate immaturity of hematopoietic progenitor cells in umbilical cord blood mononuclear cells (CB-MNC), the formation of macroscopic colonies and mixed-cell colonies was assayed by methylcellulose culture with various combinations of cytokines (stem cell factor [SCF], interleukin [IL]-3, IL-6, granulocyte-colony stimulating factor [G-CSF], erythropoietin [EPO]) and compared with bone marrow (BM)-MNC. Moreover, distribution of the subpopulations divided by CD34, CD38, HLA-DR and CD33 was compared by flow-cytometry. Colonies derived from CB-MNC were so large that they could be observed with the naked eye and consisted of a variety of types of hematopoietic cells. Mixed-cell colonies were formed to a much greater extent in CB-MNC than in BM-MNC. Addition of EPO, IL-3, and SCF had rapid effects on the growth of mixed-cell colonies. The subpopulations of immature hematopoietic progenitor cells (CD34+, CD38-, HLA-DR-), which are supposed to be able to differentiate into hematopoietic precursors and stromal cells, were significantly higher in CB-MNC (8.7 +/- 6.6%) than in BM-MNC (0.0 +/- 0.1%; P < 0.001). These results suggest that CB is a rich source of immature hematopoietic progenitor cells compared to BM.
Urashima
M
M
Department of Pediatrics, Jikei University School of Medicine, Tokyo, Japan.
Hoshi
Y
Y
Shishikura
A
A
Kamijo
M
M
Kato
Y
Y
Akatsuka
J
J
Maekawa
K
K
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D001854:Bone Marrow Cells; D016207:Cytokines; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D007231:Infant, Newborn; D017154:Stromal Cells / Q000166:cytology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D016207:Cytokines