Abstract
Three anti-macrophage monoclonal antibodies designated TRPM-1, TRPM-2 and TRPM-3 were produced, using thioglycollate-elicited rat peritoneal macrophages as imunogen. By the immunoperoxidase method, TRPM-1 reacted with most macrophages in the thymus, spleen and lymph nodes, and alveolar macrophages, Kupffer cells of the liver and blood monocytes. Moreover, TRPM-1 recognized Langerhans cells in the epidermis and IDCs in the thymus-dependent area. This antibody is thus thought to be an anti-pan-macrophage antibody. TRPM-2 exhibited a similar reaction pattern as TRPM-1 did; however, it recognized fewer macrophages than TRPM-1 did, and failed to react with Langerhans cells in the epidermis. On the other hand, TRPM-3 selectively reacted with splenic marginal zone macrophages and marginal metallophils, lymph node sinus macrophages, and spindle-shaped macrophages in the omentum. Tingible body macrophages in the lymphatic follicles and interdigitating cells in the thymus-dependent areas were not stained with TRPM-3. On immunoelectron microscopy, reaction products for TRPM-1 and TRPM-2 were observed in the cytoplasm of the macrophages, whereas reaction to TRPM-3 was clearly demonstrated on the plasma membrane of splenic marginal zone macrophages and marginal metallophils, as well as lymphatic sinus macrophages. As TRPM-1, TRPM-2, TRPM-3 recognize different macrophage populations, they are considered to be very useful tools to analyze the heterogeneity of macrophages.
