Different strains of Toxoplasma gondii induce different cytokine responses in CBA/Ca mice.
To investigate the role that cytokines may have in the development of toxoplasmic encephalitis (TE), the levels of gamma interferon (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), interleukin-12 (IL-12 ]p40[), IL-10, IL-6, IL-4, and IL-2 in serum were examined in CBA/Ca mice infected with a type II strain (ME49 or FORT) of Toxoplasma gondii. These strains caused severe (ME49) or mild (FORT) TE in CBA/Ca mice. From weeks 1 to 8 of infection, the levels of IL-6, IL-10, IL-12, IFN-gamma, and TNF-alpha in serum were significantly higher in the ME49-infected mice than in the FORT-infected mice, suggesting a role for these cytokines in the severity of TE in CBA/Ca mice. Since the ME49 and FORT strains are of the same type, our results suggest a role for the parasite in the development of severe TE through the increased production of proinflammatory cytokines and indicate that not all type II strains cause TE.
Araujo
Fausto G
FG
Research Institute, Palo Alto Medical Foundation, Palo Alto, California 94301, USA. araujof@pamfri.org
Slifer
Teri
T
D000818:Animals; D016207:Cytokines / Q000097:blood / Q000502:physiology*; D004660:Encephalitis / Q000209:etiology*; D006801:Humans; D051379:Mice; D008808:Mice, Inbred CBA; D013045:Species Specificity; D014122:Toxoplasma / Q000472:pathogenicity*; D016781:Toxoplasmosis, Cerebral / Q000209:etiology*; D014774:Virulence
D016207:Cytokines