title: A protective role for endogenous tumor necrosis factor in Toxoplasma gondii infection.
abstract: The involvement of tumor necrosis factor (TNF) in resistance to Toxoplasma gondii infection was examined by means of experiments in which mice were treated with anti-TNF antibodies prior to infection with ME49, a low-virulence Toxoplasma strain. In (BALB/cBy x C57BL/6J)F1 (CB6F1) mice, which are highly resistant to intraperitoneal (i.p.) infection with T. gondii ME49, 10(4) neutralizing units of anti-TNF caused a significant increase in trophozoite numbers in the peritoneal cavities of infected mice and transient signs of illness but no deaths. i.p. infection of anti-TNF-treated C57BL/6J (B6) mice, which are more susceptible to T. gondii and develop a chronic progressive toxoplasmosis, resulted in death for some of the mice. If the mice were infected perorally, however, and treated with anti-TNF, mortality was extensive in B6 mice but not in CB6F1 mice. Although it was not detected in their sera, TNF was found in the peritoneal fluids of i.p.-infected CB6F1 and B6 mice. Endogenously produced TNF thus appears to be an important mediator of resistance to T. gondii.
authors.affiliation: Trudeau Institute, Inc., Saranac Lake, New York 12983.
authors.forename: L L
authors.initials: LL
authors.lastname: Johnson
mesh_terms: D000818:Animals; D005260:Female; D007074:Immunoglobulin G / Q000276:immunology; D007371:Interferon-gamma / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D014124:Toxoplasmosis, Animal / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000502:physiology*
chemical_list: D007074:Immunoglobulin G; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma