GM-CSF-mobilized peripheral blood CD34+ cells differ from steady-state bone marrow CD34+ cells in adhesion molecule expression.
To determine the effect of growth factor mobilization on the expression of adhesion molecules, we compared CD34+ progenitor cell (PC) populations from steady-state bone marrow (BM) with granulocyte-macrophage colony-stimulating factor (GM-CSF)-mobilized apheresis products (peripheral blood stem cell (PSC)) using flow cytometry. To increase the accuracy of this analysis, CD34+ cells were enriched (MiniMACS) before cytometric analysis. A significantly lower expression of very late antigen-4 (VLA-4), leukocyte function antigen-1 (LFA-1) and LFA-3 were observed on PSC compared to BM CD34+ cells. In addition, significantly lower mean fluorescence intensity (MFI) of VLA-4, VLA-5, intercellular adhesion molecule-1 (ICAM-1), and sialyl Lewisx were observed on PSC as compared to BM CD34+ cells. Significantly higher levels of L-selectin and CD44 expression were observed on PSC as compared to BM CD34+ cells based on frequency and MFI (P < or = 0.05). In addition, the duration of GM-CSF administration or number of prior aphereses had no effect on adhesion molecule expression. These data suggest that decreased expression of adhesion molecules including VLA-4, LFA-1, ICAM-1 and LFA-3 play a role in PC mobilization. Based on these studies, we suggest that PC mobilization occurs as a stochastic process and is associated with the selection of CD34+ cells with low adhesion molecule expression.
Watanabe
T
T
Department of Pathology/Microbiology, University of Nebraska Medical Center, Omaha 68198-5660, USA.
Dave
B
B
Heimann
D G
DG
Lethaby
E
E
Kessinger
A
A
Talmadge
J E
JE
D000328:Adult; D000368:Aged; D018952:Antigens, CD34 / Q000378:metabolism*; D001853:Bone Marrow / Q000276:immunology*; D001854:Bone Marrow Cells; D018968:CD58 Antigens / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage*; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology*; D006689:Hodgkin Disease / Q000628:therapy; D006801:Humans; D039041:Integrin alpha4beta1; D016023:Integrins / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007937:Leukapheresis; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D008228:Lymphoma, Non-Hodgkin / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009844:Oligosaccharides / Q000378:metabolism; D016201:Receptors, Lymphocyte Homing / Q000378:metabolism; D000080506:Sialyl Lewis X Antigen; D014182:Transplantation, Autologous
D018952:Antigens, CD34; D018968:CD58 Antigens; D015815:Cell Adhesion Molecules; D039041:Integrin alpha4beta1; D016023:Integrins; D016169:Lymphocyte Function-Associated Antigen-1; D009844:Oligosaccharides; D016201:Receptors, Lymphocyte Homing; D000080506:Sialyl Lewis X Antigen; D018799:Intercellular Adhesion Molecule-1; D016178:Granulocyte-Macrophage Colony-Stimulating Factor