| First Author | Galvão Da Silva AP | Year | 2003 |
| Journal | Immunology | Volume | 108 |
| Issue | 2 | Pages | 230-7 |
| PubMed ID | 12562332 | Mgi Jnum | J:82090 |
| Mgi Id | MGI:2450824 | Doi | 10.1046/j.1365-2567.2003.01571.x |
| Citation | Galvao Da Silva AP, et al. (2003) Resistant mice lacking interleukin-12 become susceptible to Trypanosoma cruzi infection but fail to mount a T helper type 2 response. Immunology 108(2):230-7 |
| abstractText | 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. |
