Toxoplasma gondii: the role of IFN-gamma, TNFRp55 and iNOS in inflammatory changes during infection.
In order to examine the role of IFN-gamma, TNFRp55 and iNOS in inflammatory reaction during toxoplasmosis, IFN-gamma(-/-), TNFRp55(-/-) and iNOS(-/-) mice were experimentally infected with Toxoplasma gondii ME-49 strain. The organs of the mice were evaluated for histology and immunohistochemistry in detection of tissue parasitism and iNOS positive cells. IFN-gamma(-/-) mice presented mild inflammation in peripheral organs associated with a high parasitism and mortality in the acute phase of infection. In contrast, the peripheral organs of WT, TNFRp55(-/-) and iNOS(-/-) mice, presented a significant inflammatory reaction and low tissue parasitism in the same period of infection. The inflammatory lesions and tissue parasitism were increased and more severe in the Central Nervous System (CNS) of TNFRp55(-/-) and iNOS(-/-) with a progression of infection, when compared to WT mice. In these knockout animals, the inflammatory changes were associated with low levels or no expression of iNOS in TNFRp55(-/-) and iNOS(-/-) mice, respectively.
Silva
Neide Maria
NM
Immunopathology Laboratory, Institute of Biomedical Sciences, Universidade Federal de Uberlândia, 38 400-902, Uberlândia, Minas Gerais, Brazil. nmsilva@icbim.ufu.br
Vieira
Júlio César Menezes
JC
Carneiro
Claudia Martins
CM
Tafuri
Wagner Luiz
WL
D000818:Animals; D001921:Brain / Q000469:parasitology; D006321:Heart / Q000469:parasitology; D007150:Immunohistochemistry; D007249:Inflammation / Q000276:immunology; D007371:Interferon-gamma / Q000502:physiology*; D008099:Liver / Q000469:parasitology; D008168:Lung / Q000469:parasitology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D052247:Nitric Oxide Synthase Type II / Q000502:physiology*; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000502:physiology*; D013116:Spinal Cord / Q000469:parasitology; D013154:Spleen / Q000469:parasitology; D014122:Toxoplasma / Q000502:physiology*; D014124:Toxoplasmosis, Animal / Q000276:immunology* / Q000473:pathology; D053319:Tumor Necrosis Factor Decoy Receptors / Q000502:physiology*
D047888:Receptors, Tumor Necrosis Factor, Type I; D053319:Tumor Necrosis Factor Decoy Receptors; C069521:recombinant human tumor necrosis factor-binding protein-1; D007371:Interferon-gamma; D052247:Nitric Oxide Synthase Type II