Fig. 4

A skewed response of 4-1BB signal-ablated mice to IFN-γ-producing CD4⁺ Th1. a The frequency and number of CD4⁺CD25⁺Foxp3⁺ Tregs. The frequency and total number of CD4⁺CD25⁺Foxp3⁺ Treg cells in the spleen of WT and 4-1BB KO mice were determined by flow cytometric analysis 3 and 5 dpi. Dot-plots show the frequency of CD25⁺Foxp3⁺ Tregs after gating on CD4⁺ T cells. b The frequency and number of IFN-γ⁺CD4⁺ Th1 and IL-17⁺CD4⁺ Th17 cells. The frequency and number of IFN-γ⁺CD4⁺ Th1 and IL-17⁺CD4⁺ Th17 cells were determined by intracellular cytokine staining in response to PMA + ionomycin stimulation of splenocytes prepared from WT and 4-1BB KO mice 3 and 5 dpi. Values in the representative dot-plots denote the average percentage of the indicated cell populations, and bar graphs show the average ± SD of values derived from at least four mice per group. *p < 0.05; **p < 0.01; ***p < 0.001 compared with the levels of the indicated groups