Functionally different subpopulations of mouse macrophages recognized by monoclonal antibodies

Four rat anti-mouse macrophage monoclonal antibodies are described. Three of them are highly specific for macrophages, and one cross-reacts with granulocytes. All 4 antibodies do not react with membrane antigens shared by all macrophages, but with antigens present only on subpopulations of 20-50% of the cells. All antibodies are directly or indirectly cytotoxic for macrophages. The subpopulations defined by these antibodies can be correlated with certain macrophage functions. Thus, antibody M 43 eliminates macrophages that are activated by lymphokine to cytotoxicity. Antibodies M 43 and M 57 eliminate macrophages that kill antibody-coated tumor targets, and clone 102 (strictly macrophage-specific) eliminates natural killer cells. Only M 143, reacting with 10-30% of macrophages, has not yet been correlated with any function. With the use of these antibodies, cells of the macrophage lineage with specific functions can be recognized and eliminated from a given population.