title: Tumour necrosis factor, but not interferon-gamma, is essential for acquired resistance to Listeria monocytogenes during a secondary infection in mice.
abstract: Mice with a secondary Listeria monocytogenes infection eliminate the bacteria much faster and more efficiently from their organs than mice with a primary infection. During the course of a secondary infection, serum concentrations of interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF) are higher than during a primary infection. The aim of the present study was to determine whether these cytokines are involved in the acquired resistance to L. monocytogenes during a secondary infection in mice. In order to neutralize cytokines, alginate-encapsulated cells, which form anti-cytokine monoclonal antibodies, were injected into the nuchal region of mice during a Listeria infection. Mice recovered from a sublethal primary Listeria infection, which acquired cell-mediated immunity, received a subcutaneous injection of anti-IFN-gamma-forming cells, or anti-TNF-forming cells, and 4 days later received an intravenous injection with 10 50% lethal dose (LD50) L. monocytogenes. The number of bacteria recovered from the liver and spleen of immune mice treated with anti-IFN-gamma-forming cells was slightly larger (approximately 1 log10) than that found for immune mice treated with anti-beta-galactosidase-forming cells, called immune control mice. The organs of immune mice treated with anti-TNF-forming cells yielded significantly more (approximately 4 log10) bacteria than those of immune control mice, more than those of immune mice treated with anti-IFN-gamma-forming cells, and comparable numbers to those of non-immune mice. Taken together, these results demonstrate that TNF is essential in acquired resistance to L. monocytogenes during a secondary infection in mice, while IFN-gamma plays a minor role.
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007111:Immunity, Cellular; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory / Q000276:immunology*; D007371:Interferon-gamma / Q000276:immunology*; D008089:Listeria monocytogenes / Q000254:growth & development; D008088:Listeriosis / Q000276:immunology*; D008099:Liver / Q000382:microbiology; D008262:Macrophage Activation; D051379:Mice; D008808:Mice, Inbred CBA; D013154:Spleen / Q000382:microbiology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D007074:Immunoglobulin G; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma