IMMUNO-HISTOCHEMICAL, LECTIN-HISTOCHEMICAL, AND ENZYME-HISTOCHEMICAL CHARACTERIZATION OF HUMAN BONE-MARROW ENDOTHELIUM

''Homing'' of hematopoietic progenitor cells to the bone marrow occurs during the clinical practice of bone marrow transplantation. Its mech anism is unknown, although adhesive interactions between hematopoietic cells and sinusoidal endothelium in the bane marrow may be implicated . Studies of human bone marrow endothelial cells have previously been limited by the lack of markers for these cells. In this report, we des cribe positive staining of bone marrow endothelial cells from human bo ne marrow trephine biopsies with antibody to factor VIII-related antig en (FVIIIR-Ag) (Dako, High Wycombe, UK), the plant lectin Ulex europae us agglutinin-I (UEA-I), and two mouse monoclonal antibodies, BMA120 a nd QBEND/10. In addition, alkaline phosphatase could be demonstrated i n the majority of marrow endothelial cells using a novel enzyme histoc hemical technique. These studies defined the marker profile of human m arrow endothelium. The results of this study will facilitate the isola tion and culture of human marrow endothelial cells for in vitro studie s of their roles in hematopoietic stem cell homing.