| Autor: |
Galvão Da Silva AP; Departamento de Patologia, Centro de Ciências da Saúde, Universidade Federal de Pernambuco, Recife, Pernambuco, Brazil., Jacysyn JF, De Almeida Abrahamsohn I |
| Jazyk: |
angličtina |
| Zdroj: |
Immunology [Immunology] 2003 Feb; Vol. 108 (2), pp. 230-7. |
| DOI: |
10.1046/j.1365-2567.2003.01571.x |
| Abstrakt: |
Interleukin-12 (IL-12) is essential to resistance to Trypanosoma cruzi infection because it stimulates the synthesis of interferon-gamma (IFN-gamma) that activates macrophages to a parasiticidal effect. Investigation of mice deprived of IL-12 genes (IL-12 knockout mice) has confirmed the important role of IL-12 and IFN-gamma in controlling parasitism in T. cruzi infection. However, it has not yet been addressed whether a shift towards a T helper type 2 (Th2) pattern of cytokine response occurred in these mice that might have contributed to the aggravation of the infection caused by IL-12 deprivation. We examined the course of T. cruzi (Y strain) infection and the regulation of cytokine responses and nitric oxide production in C57BL/6 IL-12 p40-knockout mice. The mutant mice were extremely susceptible to the infection as evidenced by increased parasitaemia, tissue parasitism and mortality in comparison with the control C57BL/6 mouse strain (wild-type) that is resistant to T. cruzi. A severe depletion of parasite-antigen-specific IFN-gamma response, without an increase in IL-4 or IL-10 production, accompanied by reduced levels of nitric oxide production was observed in IL-12 knockout mice. We found no evidence of a shift towards a Th2-type cytokine response. In IL-12 knockout mice, the residual IFN-gamma production is down-regulated by IL-10 but not by IL-4 and nitric oxide production is stimulated by tumour necrosis factor-alpha. Parasite-specific immunoglobulin G1 antibody levels were similar in IL-12 knockout and wild-type mice, whereas IL-12 knockout mice had much higher levels of immunoglobulin G2b. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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