In vitro studies on normal, stimulated and immunologically activated mouse macrophages. III. Intracellular multiplication of Listeria monocytogenes.

The intracellular generation time of Listeria monocytogenes is increased in monolayers of PE macrophages from mice immunized with BCG, listeria and T.A.B. vaccine as compared with monolayers of PE macrophages from normal mice stimulated intraperitoneally with proteosepeptone. Thus non-specifically stimulated and immunologically activated macrophages, although sharing several other characteristics, differ in their capacity to control intracellular bacterial infection.