MONOCLONAL-ANTIBODIES AGAINST THE HUMAN MANNOSE RECEPTOR AS A SPECIFIC MARKER IN FLOW-CYTOMETRY AND IMMUNOHISTOCHEMISTRY FOR MACROPHAGES

Recently we developed mouse monoclonal antibodies (mAb) against the is olated human 175-kDa mannose receptor, In the present study we tested whether these mAb are suitable for the detection of the mannose recept or on cultured macrophages using flow cytometry and on cells in human tissues using immunohistochemistry. Human monocytes did not react with the mAb in flow cytometry, Mannose receptor expression became detecta ble on monocytes cultured for 3 days (macrophages), and was maximal fr om 4 days onward, The mannose receptor was up-regulated on dexamethaso ne-treated (immunosuppressed) macrophages, and down-regulated on lipop olysaccharide-treated (activated) macrophages, Immunohistochemically t he staining pattern of our mAb was compared with the marker of monocyt es/macrophages KP1, In a bone marrow smear, only macrophages were stai ned with our mAb, whereas all myeloid cells were stained with KP1, In the thymus and lymph node, mannose receptor-positive branched cells (m acrophages and dendritic cells) were detected in connective tissue, th ymus cortex (not medulla), and in the T cell area (not the B cell area ) of lymph nodes, whereas KP1 stained branched cells in all areas, It was concluded that the mAb are useful tools in now cytometry and immun ohistochemistry for the specific detection of cells expressing mannose receptor.