Membrane-bound delta-4 notch ligand reduces the proliferative activity of primitive human hematopoietic CD34+CD38low cells while maintaining their LTC-IC potential.
To examine the role of the Notch ligand Delta-4 on hematopoietic stem cells, human CD34+CD38low cord blood cells were cocultured on S17 cells transduced with transmembrane Delta-4 (mbD4/S17) or an empty vector (C/S17). By the end of a 3-week culture, mbD4/S17 induced a 25-fold reduction in nucleated cell production, as compared to C/S17, by maintaining a higher proportion of cells in G0/G1 phase. A specific retention of a high proportion of CD34+ cells throughout the culture was observed with mbD4/S17, contrary to C/S17. Although mbD4/S17 promoted expansion of cells with the phenotype of committed lymphoid precursors (CD34+CD7+CD45RA+), these cells still retained their myeloid differentiation potential. mbD4/S17 maintained a higher LTC-IC frequency in output CD34+ cells, compared to C/S17, as in the subsets of cells having completed the same number of divisions on mbD4/S17. A Delta4-Fc protein (extracellular part of human Delta4 fused to Fc human IgG1 portion), immobilized on plastic, also reduced cell production and retained the LTC-IC potential. Transplantation of cells grown on mbD4/S17 into NOD/SCID mice showed no significant enhancement of the long-term repopulating ability. Thus, Delta4 appears to inhibit hematopoietic stem cell proliferation, in association with the maintenance of short-term lymphoid and myeloid repopulation capacity.
U362 INSERM - PR1, Institut Gustave Roussy, 39 rue C. Desmoulins, Villejuif, France. elauret@igr.fr
E
E
Lauret
C
C
Catelain
M
M
Titeux
S
S
Poirault
J S
JS
Dando
M
M
Dorsch
J-L
JL
Villeval
A
A
Groseil
W
W
Vainchenker
F
F
Sainteny
A
A
Bennaceur-Griscelli
D036541:ADP-ribosyl Cyclase / Q000032:analysis; D051997:ADP-ribosyl Cyclase 1; D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D015703:Antigens, CD / Q000032:analysis; D018952:Antigens, CD34 / Q000032:analysis; D001798:Blood Proteins / Q000235:genetics* / Q000502:physiology*; D002135:Calcium-Binding Proteins; D002454:Cell Differentiation; D002455:Cell Division; D018920:Coculture Techniques; D005312:Fetal Blood / Q000166:cytology; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics* / Q000502:physiology*; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D051379:Mice; D016688:Mice, Inbred NOD; D016192:Resting Phase, Cell Cycle; D014161:Transduction, Genetic; D014183:Transplantation, Heterologous
D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD; D018952:Antigens, CD34; D001798:Blood Proteins; D002135:Calcium-Binding Proteins; C424126:DLL4 protein, human; D036341:Intercellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D036541:ADP-ribosyl Cyclase; C498154:CD38 protein, human; C498155:Cd38 protein, mouse; D051997:ADP-ribosyl Cyclase 1