Indeed, nude mice are often more resistant to infection, explain. Monoclonal antibodies that prevented migration of neutrophils from the blood into sites of inflammation converted a sublethal infection into a lethal one. NK cells make gamma interferon that is critical for macrophage activation in the absence of T-cells, gamma interferon is actually higher TNF is an essential cytokine. Necessary for granuloma production in liver. D. Survivors of sublethal infection are immune to 5-logs times the normal LD 50 two weeks after challenge.
Immunity is initially non-specific and can be attributed to macrophage activation.
E. Killed bacteria do not provide protective immunity . Will return to this question at the end of the lectures. This is an extremely important observation. The assay L. monocytogenes infects most, if not all, adherent cells and macrophages. The efficiency of internalization can vary over 4-logs.