Monoclonal antimacrophage antibodies: human pulmonary macrophages express HLA-DR (Ia-like) antigens in culture.

Study of human macrophages and their role in disease has been hampered by lack of well-characterized tissue macrophages. We describe a simple procedure to obtain viable adherent cells in good yield from resected lung, characterize the cells as greater than 95% macrophage by standard criteria, and document expression of marker properties previously described in rodent macrophages. Human pulmonary macrophages were used to produce monoclonal antibodies and to study expression of HLA-A,B,C, HLA-DR, and related antigens. A new monoclonal mouse antibody, 18, showed restricted binding to macrophages from human lung or blood and to B lymphoid cells, but did not bind to closely related cells. With antibody 18 and other monoclonal antibodies of known specificity, DA2 and Genox 3.53, we showed that a remarkably high proportion of human pulmonary macrophages express HLA-DR framework and DC1 polymorphic determinants in culture. Although the macrophages differed in source and in their state of activation, single cell analysis revealed no heterogeneity in antigen expression.