[Immunobiology of tuberculosis]

R. Koch showed in 1882 in his so-called fundamental experiment that tuberculous guinea pigs exhibit a vigorous immunity against re-infection. In investigations in 1930--40 we showed that this immunity is not mediated by humoral antibodies. It is a cellular process, a local and general activation of the macrophage system (the system of mononuclear phagocytes). The tuberculous granuloma consists of activated macrophages and their descendants (epitheloid and giant cells), which inhibit the growth and spreading of tubercle bacilli. The role of the specific and unspecific activation of the macrophage system could be demonstrated in experiments on rats, infected with Bartonella muris ratti. These early results are related to the recent knowledge concerning cellular immunity and granulomatous inflammation, especially to the cooperation between the lymphatic and macrophage system.