Macrophage characteristics of a cell line isolated in vitro from a Moloney lymphoma

A new cell line, LM-A, established in vitro from a murine Moloney lymphoma, is described. The line shows the cytologic, adherence, and phagocytic properties of normal macrophages. It forms specific rosettes with antibody-coated erythrocytes. The cells mediate antibody-dependent cellular cytotoxicity as assayed by release of radioactivity from 51Cr-labeled erythrocytes. The cytolytic reaction proved to be functionally distinct from the phagocytic process as demonstrated by enhanced cytolysis in the presence of iodo-acetamide, an inhibitor of phagocytosis. The line has Moloney murine leukemia virus (MLV)-related antigens as detected by membrane immunofluorescence. The LM-A line is useful for the study of macrophage functions and also provides an interesting tool for investigating the antigenic and immunogenic properties induced by MLV in a cell as relevant as the macrophage in the immune response.