Late committed progenitor cells of erythropoiesis, CFU-E (colony-forming unit--erythroid), were isolated from mouse spleens to near homogeneity by a three-step enrichment procedure. The procedure included a four-day pretreatment of bled mice with the antibiotic thiamphenicol, a recovery period of 3 1/2 days, followed by centrifugal elutriation and Percoll density gradient centrifugation of the ...

It has been suggested that the BCR-ABL gene of chronic myeloid leukemia (CML) is not uniformly expressed in Philadelphia (Ph)-positive cells, and that BCR-ABL gene expression precludes transcription of the normal BCR or ABL genes. Therefore, we have analyzed granulocyte-macrophage colony-forming unit (CFU-GM) colonies derived from peripheral blood of 11 CML patients by cytogenetic and by revers...

We have examined the effects of 10 different growth factors either alone or in combination on colony-forming unit-spleen (CFU-S) and repopulating stem cell survival in vitro. Either interleukin-3 (IL-3), granulocyte-colony-stimulating factor (G-CSF), or IL-4 alone support CFU-S in vitro. The effects of IL-3 or G-CSF could be neutralized by adding antibodies against IL-3 or G-CSF, respectively. ...

The effect of FLT3/FLK2 ligand (FL) on the growth of primitive hematopoietic cells was investigated using ThyloSca1+ stem cells. FL was observed to interact with a variety of factors to initiate colony formation by stem cells. When stem cells were stimulated in liquid culture with FL plus interleukin (IL)-3, IL-6, granulocyte colony-stimulating factor (G-CSF), or stem cell factor (SCF), cells c...

OBJECTIVE We investigated the role of human stromal layers (hu-ST) on the ex vivo expansion/maintenance of human hematopoietic stem/progenitor cells (HSC) from adult bone marrow (BM) and umbilical cord blood (CB). MATERIALS AND METHODS BM and CB CD34(+)-enriched cells were cultured in serum-free medium supplemented with SCF, bFGF, LIF, and Flt-3, in the presence or absence of stroma, and anal...

OBJECTIVE There have been various reports on the roles of CXC receptors (CXCR) in modulation of hematopoiesis. In the present study, we investigated the effects of CXCR1 and/or CXCR2 inhibition on expansion and differentiation of umbilical cord blood (UCB) CD133(+) cells into megakaryocytic progenitors. MATERIALS AND METHODS Purified UCB CD133(+) cells were cultured in a serum-free liquid cul...

We investigated the effects of murine resident peritoneal macrophages on the in vitro proliferation of erythropoietin (Ep)-sensitive committed precursors colony-forming unit-erythroid (CFU-E) and burst-forming unit-erythroid (BFU-E) with a two-layer cloning system of methylcellulose and semisolid agar. The addition of increasing numbers of macrophages to the agar underlayer resulted in a progre...

Interleukin-7 (IL-7) is an important growth factor in B and T lymphopoiesis in mouse and human, whereas IL-7 has been regarded to lack proliferative effects on cells within the myeloid lineage. However, we have recently reported that IL-7 potently can enhance colony stimulating factor (CSF)-induced myelopoiesis from primitive murine hematopoietic progenitors, showing a novel role of IL-7 in ear...

Increasing evidence especially stemming from peripheral blood progenitor transplantation studies points to a possible biologic difference between mobilized blood and bone marrow progenitor cells. The objective of this study was to compare the in situ radiation sensitivity of recombinant human granulocyte colony-stimulating factor (rhG-CSF)-recruited circulating granulopoietic (blood colony-form...