[Cellular antibacterial immunity (author's transl)].

Facultatively intracellular bacteria (Mycobacteria, Brucellae, Listeria monocytogenes, Salmonella typhi etc.) may not necessarily be killed after having being phagocytosed by polymorphonuclear leucocytes or macrophages, cellular immunity having first to be built up. This results in the formation of specifically committed T-lymphocytes, which in turn release lymphokines after restimulation by homologous antigen. Under the effect of lymphokines, mononuclear phagocytes are chemotactically attracted to the site of infection, granulomas are formed and macrophages within the granuloma are activated. The granuloma represents the tissue reaction within which the interaction between facultatively intracellular bacteria and defence factors takes place. The experimental details underlying this concept are reviewed.