IMMUNOHISTOCHEMICAL CHARACTERIZATION OF 2 NOVEL MONOCLONAL-ANTIBODIESTHAT RECOGNIZE HUMAN PERIVASCULAR CELLS OF THE CENTRAL-NERVOUS-SYSTEMAND MACROPHAGE SUBSETS

Two monoclonal antibodies to cells of monocyte/macrophage lineage were established using a human glial cell-rich fraction as the immunogen. The antibodies, named GP-1 and GP-2, were originally found to react wi th perivascular cells of the central nervous system. They are immunohi stochemically applicable on routinely formalin-fixed, paraffin-embedde d tissue sections. GP-1 binds to a lysosomal protein, and GP-2 to a ca rbohydrate epitope of the cell membrane and lysosomes. Among the visce ral organs, GP-1 labeled brood monocytes, almost ail kinds of tissue a nd infiltrating macrophages in both normal and diseased states, and re nal tubules. GP-1 staining of tissue macrophages tends to be intensifi ed under inflammatory conditions. GP-1 staining also suggested that pe rivascular cells and macrophages had different ontogeny. GP-2 immunost ained monocytes, Kupffer's cells, red pulp macrophages, infiltrating m acrophages and reactive microglia, but not alveolar or tingible body m acrophages. Besides those macrophages, GP-2 stained mantle zone lympho cytes, some hematopoietic cells, pneumocytes and renal collecting duct s. The staining pattern of ligands an THP-1 and HL-60 neoplastic human macrophage cell lines was dissimilar to that of other macrophage mark ers, suggesting that they recognize unknown macrophage-related antigen s.