Relationship between Thy-1 expression and cell-cycle distribution in human bone marrow hematopoietic progenitors.
Analysis of the relationship between Thy-1 expression and cell-cycle distribution of hematopoietic stem cells (HSCs) showed that freshly isolated Thy-1+ and Thy-1- subsets of the CD34highCD38-flt-3-Lin- population were predominantly in G0/G1 phase and remained essentially quiescent, whereas after 6 days of cytokine stimulation, the Thy-1+ subset of the population entered the cycling state while the Thy-1- subset again remained quiescent. Expression of Thy-1 antigen resulted in a drastic increase in the percentage of cycling cells in CD34highCD38-flt-3-Lin-Thy-1+- as well as CD34highCD38-flt-3-Lin- Thy-1(-)-cell-initiated cultures. The Thy-1+ subset of the CD34highCD38-flt-3-Lin- population exists in the freshly isolated CD34highCD38-flt-3-Lin- Thy-1+ fraction, loses Thy-1 expression during 6 days, and re-expresses Thy-1 for an additional 2 days. Cell-cycle analysis demonstrated that this unique subset contains abundant S/G2M cells. Thus, Thy-1 expression appears to be an indicator of cell-cycle phase in targeting HSC, which might serve in the cell subset best suited for gene transfer.
Department of Pediatrics, Hyogo College of Medicine, Hyogo, Japan. take-ped@hyo-med.ac.jp
Hiroki
H
Takeda
Masuji
M
Yamamoto
Naoko
N
Morita
Takakuni
T
Tanizawa
D018952:Antigens, CD34; D015415:Biomarkers / Q000032:analysis; D001854:Bone Marrow Cells / Q000166:cytology*; D018929:Cell Culture Techniques; D002453:Cell Cycle; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology; D005434:Flow Cytometry; D016195:G2 Phase; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D016130:Immunophenotyping; D007399:Interphase; D016196:S Phase; D018800:Thy-1 Antigens / Q000032:analysis*
D018952:Antigens, CD34; D015415:Biomarkers; D016207:Cytokines; D018800:Thy-1 Antigens