Immunophenotypic and functional characterization of CD33(+)CD34(+) cells in human cord blood of preterm neonates.
OBJECTIVE
To characterize CD33(+)CD34(+) cells, a major population in human cord blood (CB) CD34(+) cells of preterm neonates.


METHODS
The proportion of CD33(+) cells was analyzed on CB CD34(+) cells from preterm and full-term neonates. CD33(+)CD34(+) cells were purified by cell sorting and analyzed on their clonogenic activity, proliferative activity in short-time liquid suspension culture, and GATA-2 mRNA expression by RT-PCR and Southern blot.


RESULTS
The absolute numbers and proportion of CD34(+) cells in mononuclear cells inversely correlated with gestational age. CD33 was expressed on a majority of CB CD34(+) cells of preterm neonates but on only a minor population of them in full-term neonates. In addition, CD33 was dominantly expressed on CD38(-)CD34(+) cells or CD117(low)CD34(+) cells in CB of preterm neonates. CD33(+)CD34(+) cells of preterm cord blood had high proliferative and reproducible potentials compared with CD33(-)CD34(+) cells. CD33(+)CD34(+) cells as well as CD33(-)CD34(+) cells from preterm CB highly expressed GATA-2, in contrast to those from BM.


CONCLUSIONS
These results suggest that CD33(+)CD34(+) cells, which are a major population in CB CD34(+) cells of preterm neonates, do not simply represent relatively mature myeloid lineage hematopoietic progenitor cells as those in adult BM CD34(+) cells, and may contain hematopoietic stem cells or primitive progenitor cells as in fetal liver.
Jin
C H
CH
Departments of Pediatrics, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
Takada
H
H
Nomura
A
A
Takahata
Y
Y
Nakayama
H
H
Kajiwara
M
M
Nakano
H
H
Hara
T
T
D015703:Antigens, CD / Q000032:analysis*; D018952:Antigens, CD34 / Q000032:analysis*; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis*; D015139:Blotting, Southern; D001854:Bone Marrow Cells / Q000737:chemistry; D002469:Cell Separation; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics; D005312:Fetal Blood / Q000166:cytology*; D005434:Flow Cytometry; D050989:GATA2 Transcription Factor; D015870:Gene Expression; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000276:immunology*; D006801:Humans; D016130:Immunophenotyping; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood*; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D063268:Sialic Acid Binding Ig-like Lectin 3; D014157:Transcription Factors / Q000235:genetics
D015703:Antigens, CD; D018952:Antigens, CD34; D015214:Antigens, Differentiation, Myelomonocytic; C571163:CD33 protein, human; D004268:DNA-Binding Proteins; D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; D012333:RNA, Messenger; D063268:Sialic Acid Binding Ig-like Lectin 3; D014157:Transcription Factors