Interaction between normal or irradiated macrophages and lymphocytes in mice

Electron microscopic observations showed that normal peritoneal macrophages and lymphocytes are found in close apposition with one another and that extensive areas of close flattened surfaces exist between the two cell types. By contrast, peritoneal macrophages, irradiated in vivo, did not display similar areas of interaction with added normal lymph node lymphocytes. The failure of irradiated macrophages to interact closely with lymphocytes may be responsible for their inability to induce antibody production against several antigens.