Flt3-ligand induces adhesion of haematopoietic progenitor cells via a very late antigen (VLA)-4- and VLA-5-dependent mechanism.
The adhesion of haematopoietic progenitor cells (HPC) to the bone marrow microenvironment is a process regulated by cytokines. In this study, we have shown that flt3-ligand (FL), a growth factor that controls early haematopoiesis, regulated the function and expression of the beta-1 integrins, very late antigen (VLA)-4 and VLA-5 on HPC. The modulation of the adhesiveness of HPC by FL was studied by adhesion assays on umbilical vein endothelial cells (HUVEC). Stimulation by FL induced two peaks of increased adhesiveness of HPC. The first peak was at around 30 min and was mechanistically related to an activation of the beta-1 integrins, mainly VLA-4 and VLA-5. The second peak was at around 12 h and was related to increased expression of VLA-4 and VLA-5. The control of HPC adhesiveness by FL is a previously unreported property of FL that may be important for the homing and the retention of flt3-expressing HPC within the bone marrow microenvironment.
Solanilla
Anne
A
UMR 5540, Université Victor Ségalen Bordeaux 2, Bordeaux, France.
Grosset
Christophe
C
Duchez
Pascale
P
Legembre
Patrick
P
Pitard
Vincent
V
Dupouy
Maryse
M
Belloc
Françis
F
Viallard
Jean-François
JF
Reiffers
Josy
J
Boiron
Jean-Michel
JM
Coulombel
Laure
L
Ripoche
Jean
J
D018952:Antigens, CD34 / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D002478:Cells, Cultured; D004730:Endothelium, Vascular; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D039041:Integrin alpha4beta1 / Q000378:metabolism*; D039081:Integrin alpha5beta1 / Q000378:metabolism*; D008565:Membrane Proteins / Q000502:physiology*; D014471:Umbilical Veins
D018952:Antigens, CD34; D039041:Integrin alpha4beta1; D039081:Integrin alpha5beta1; D008565:Membrane Proteins; C084881:flt3 ligand protein