title: Rapid differentiation of a rare subset of adult human lin(-)CD34(-)CD38(-) cells stimulated by multiple growth factors in vitro.
abstract: Recently, several reports of lineage-negative (lin(-)) CD34(-) cells with in vivo hematopoietic activity have focused interest on the properties and growth factor response characteristics of these cells. We have now identified a combination of 5 growth factors that are necessary and sufficient to stimulate a marked mitogenic and differentiation response by a subset of human lin(-)CD34(-)CD38(-) cells present in normal adult human marrow and granulocyte colony-stimulating factor (G-CSF)-mobilized blood. Less than 0.1% of the cells in highly purified (including doubly sorted) lin(-)CD34(-)CD38(-) cells from these 2 sources formed colonies directly in semisolid medium or generated such cells after 6 weeks in long-term culture. Nevertheless, approximately 1% of the same lin(-)CD34(-)CD38(-) cells were able to proliferate rapidly in serum-free liquid suspension cultures containing human flt-3 ligand, Steel factor, thrombopoietin, interleukin-3 (IL-3), and hyper-IL-6 to produce a net 28- +/- 8-fold increase in total cells within 10 days. Of the cells present in these 10-day cultures, 5% +/- 2% were CD34(+) and 2.5% +/- 0.9% were erythroid, granulopoietic, megakaryocytopoietic, or multilineage colony-forming cells (CFC) (13 +/- 7 CFC per lin(-)CD34(-)CD38(-) pre-CFC). In contrast to lin(-)CD34(+)CD38(-) cells, this response of lin(-)CD34(-)CD38(-) cells required exposure to all of the 5 growth factors used. Up to 1.7 x 10(5) lin(-)CD34(-) adult marrow cells failed to engraft sublethally irradiated NOD/SCID-beta(2)M(-/-) mice. These studies demonstrate unique properties of a rare subset of lin(-)CD34(-)CD38(-) cells present in both adult human marrow and mobilized blood samples that allow their rapid proliferation and differentiation in vitro within an overall period of 3 to 4 weeks. The rapidity of this response challenges current concepts about the normal duration and coordinated control of these processes in adults.
authors.affiliation: Terry Fox Laboratory, British Columbia Cancer Agency, and the University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Fujisaki
authors.forename: M G
authors.initials: MG
authors.lastname: Berger
authors.forename: S
authors.initials: S
authors.lastname: Rose-John
authors.forename: C J
authors.initials: CJ
authors.lastname: Eaves
mesh_terms: D036541:ADP-ribosyl Cyclase; D051997:ADP-ribosyl Cyclase 1; D000328:Adult; D000818:Animals; D015703:Antigens, CD / Q000032:analysis*; D018952:Antigens, CD34 / Q000032:analysis; D000943:Antigens, Differentiation / Q000032:analysis; D015415:Biomarkers; D001854:Bone Marrow Cells / Q000166:cytology* / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D005434:Flow Cytometry; D006133:Growth Substances / Q000494:pharmacology*; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects; D006801:Humans; D008562:Membrane Glycoproteins; D051379:Mice; D009244:NAD+ Nucleosidase / Q000032:analysis
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D000943:Antigens, Differentiation; D015415:Biomarkers; D006133:Growth Substances; D008562:Membrane Glycoproteins; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; C498155:Cd38 protein, mouse; D009244:NAD+ Nucleosidase; D051997:ADP-ribosyl Cyclase 1