Mice 6 days after thermal injury (TI-mice) did not respond to lipopolysaccharide (LPS) stimulation for production of serum interleukin 12 (IL-12; 2h after LPS stimulation, <20 pg/ml in TI-mice; 1091 ± 162 pg/ml in normal mice). However, 2h after LPS stimulation, 1456 ± 118 pg/ml of IL-12 were demonstrated in sera of TI-mice previously treated with a 10 mg/kg i.p. dose of glycyrrhizin (GR). IL-12 was not induced by LPS in sera of normal mice inoculated with burn-associated type 2 T cells (IL-4/IL-10-producing CD8+ CD11b+ TCRγ/δ+ T cells isolated from spleens of TI-mice). However, IL-12 production was induced by LPS in sera of these mice previously treated with GR or a mixture of monoclonal antibodies (mAbs) for type 2 cytokines. Also, IL-12 production was induced by LPS in TI-mice inoculated with CD4+ T cells from spleens of GR-treated normal mice (GR-CD4+ T cells, 5 × 106 cells/mouse). Since GR-CD4+ T cells have been shown to be antagonistic cells against production of type 2 cytokines by burn-associated type 2 T cells, these results indicate that IL-12 unresponsiveness shown in TI-mice is recovered by GR through the regulation of burn-associated type 2 T cell responses.
- Burn-associated type 2 T cells
ASJC Scopus subject areas
- Immunology and Allergy
- Molecular Biology