Influence of cytokine stimulation (granulocyte macrophage-colony stimulating factor, interleukin-3 and transforming...

Interactions between stromal cells or extracellular matrix and hematopoietic cells are important factors for the very complex processes associated with differentiation and maturation in the bone marrow. To elucidate these multifold processes, the expression pattern of various adhesion molecules was studied on enriched fibroblastic populations derived from healthy volunteers. CD44 (homing cell adhesion molecule) and very late activation antigen beta 1 (VLA beta 1; CD29) could be demonstrated on almost all fibroblasts without an alteration following cytokine stimulation. On the other hand, VLA-2 (CDw49b), VLA-3 (CDw49c), VLA-4 (CDw49d), VLA-5 (CDw49e), intercellular adhesion molecule-1 (ICAM-1; CD54) and vascular cell adhesion molecule-1 (VCAM-1; CD106) were only represented by certain cell fractions. In our studies recombinant human granulocyte macrophage-colony stimulating factor failed to alter the expression pattern of these adhesion molecules, whereas recombinant human interleukin-3 (rhIL-3 showed a tendency for downregulation of the VLA antigens except for VLA beta 1. However, recombinant human transforming growth factor-beta 1 (rhTGF beta 1) exerted a reducing effect on the expression of VLA-3 and induced an increase in the VLA-5-positive fraction. In the immunoglobin class VCAM-1 revealed a decrease staining capacity after stimulation with rhTGF beta 1 and rhIL-3. Contrary to this finding, the presentation of ICAM-1 increased after administration of these mediators.