Cytokine and antibody responses of reactivated murine toxoplasmosis upon administration of dexamathasone.
10.3347/kjp.2006.44.3.209
- Author:
Ki Nam KANG
1
;
In Uk CHOI
;
Dae Whan SHIN
;
Young Ha LEE
Author Information
1. Department of Infection Biology, College of Medicine, Chungnam National University, Daejeon 301-131, Korea. yhalee@cnu.ac.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Toxoplasma gondii;
dexamethasone;
cytokine;
antibody;
mouse;
Th1;
Th2 response
- MeSH:
Toxoplasmosis/*immunology/parasitology;
Toxoplasma/*immunology;
Th2 Cells/immunology;
Th1 Cells/immunology;
Mice, Inbred BALB C;
Mice;
Immunoglobulins/*biosynthesis/immunology;
Female;
Dexamethasone/*pharmacology;
Cytokines/*biosynthesis;
Antibodies, Protozoan/*biosynthesis/immunology;
Animals
- From:The Korean Journal of Parasitology
2006;44(3):209-219
- CountryRepublic of Korea
- Language:English
-
Abstract:
Toxoplasma gondii has been shown to result in life-threatening encephalitis in immunocompromised patients after reactivation of dormant parasites. In order to obtain information on immune responses related to this phenomenon, BALB/c mice were infected with 25 cysts of the 76K strain of T. gondii, then, treated orally with dexamethasone (Toxo/Dexa-treated group) in order to reactivate the chronic toxoplasmosis. None of the T. gondii-infected mice died during the experimental periods, whereas the Toxo/Dexa-treated mice evidenced a significant attenuation of survival periods. Toxoplasma-specific IgG2a, IgA and IgM titers in sera were significantly depressed in the Toxo/Dexa-treated mice; however, the IgG1 sera titers were similar to those seen in the Toxoplasma-infected mice. The percentages of CD4+ and CD8 alpha + T cells in the Toxo/Dexa-treated mice were significantly reduced 2 weeks after dexamethasone treatment. IFN-gamma and IL-10 production levels in the Toxo/Dexa-treated mice were depressed significantly, whereas IL-4 production was increased temporarily. The expression levels of the Toxoplasma-specific P30 and B1 genes were found to have been increased in the Toxo/Dexa-treated mice in comparison with the Toxoplasmainfected mice. Collectively, the findings of this study demonstrate that reactivation of murine toxoplasmosis as the result of dexamethasone treatment induced a depression in Th1 immune responses, whereas Th2 immune responses were not significantly influenced.
