Mobilization of hematopoietic primitive and committed progenitor cells into blood in mice by anti-vascular adhesion molecule-1 antibody alone or in combination with granulocyte colony-stimulating factor

Objective. One of the mechanisms for mobilization of hematopoietic stem cel ls and progenitor cells is alternation of adhesion molecules, We investigat ed the mobilization of hematopoietic progenitor cells in blood by administr ation of anti-vascular cell adhesion molecule (VCAM)-1 antibody (Ab) in mic e. Materials and Methods. Twelve- to 14-week-old C57BL/6J mice were injected i ntravenously with anti-VCAM-1 Ab and anti-very late antigen (VLA)-4 Ab at a dose of 5 mg/kg for 2 days. Results. The number of colony-forming cells (CFCs) in blood was increased 1 1.4-fold after anti-VCAM-1 Ab treatment, but the number of CFCs was not inc reased after treatment with anti-VLA-4 Ab. The number of colony-forming uni t spleen (CFU-S) also was increased 21.6-fold in the peripheral blood by ad ministration of anti-VCAM-1 Ab, The number of CFCs and CFU-S in the bone ma rrow of mice treated with anti-VCAM-1 Ab was decreased and that in the sple en also was decreased, On administration of recombinant human granulocyte c olony-stimulating factor (125 mu g/kg twice daily) with anti-VCAM-1 Ab, the numbers of CFCs and CFU-S were increased 141.8-fold acid 439-fold, respect ively. Conclusion. These observations demonstrated that administration of anti-VCA M-1 Ab induced mobilization of hematopoietic progenitor cells into blood fr om bone marrow and spleen and that granulocyte colony-stimulating factor ha s synergistic effects on anti-VCAM-1 Ab-induced mobilization. (C) 2000 Inte rnational Society for Experimental Hematology, Published by Elsevier Scienc e Inc.