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 β1 (VLAβ1; 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; CD 106) 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 VLAβ1. However, recombinant human transforming growth factor-β1 (rhTGFβ1) exerted a reducing effect on the expression of VLA-3 and induced an increase in the VLA-5-positive fraction. In the immunoglobulin class VCAM-1 revealed a decreased staining capacity after stimulation with rhTGFβ1 and rhIL-3. Contrary to this finding, the presentation of ICAM-1 increased after administration of these mediators.