Figure 7: Lkb1 promotes the expression of diverse immunosuppressive genes.

(a) CD44^highCD62L^low effector/memory cells among splenic CD4⁺Foxp3⁻ and CD8⁺Foxp3⁻ T cells from 9–11-day-old Foxp3^Cre and Foxp3^CreLkb1^f/f mice (n=4–6). (b) Intracellular staining of cytokines in splenic CD4⁺Foxp3⁻ and CD8⁺Foxp3⁻ T cells from 9–11-day-old Foxp3^Cre and Foxp3^CreLkb1^f/f mice stimulated with phorbol myristate acetate (PMA) and ionomycin for 4 h. (c) Percentages of Foxp3⁺ T_reg cells among CD4⁺ T cells in the spleen and lymph nodes from 9–11-day-old Foxp3^Cre and Foxp3^CreLkb1^f/f mice (n=5). (d) Suppression of proliferation of CFSE-labelled T_n cells (responding cells, T_resp) by different ratios of CD4⁺YFP⁺ T_reg cells from Foxp3^Cre and Foxp3^CreLkb1^f/f mice. T_respcell division was determined by CFSE dilution at the indicated ratios of cell numbers between T_reg cell and T_resp cells. The experiment was repeated three times. (e) T_reg cell function-related genes differentially expressed between CD4⁺YFP⁺ T_reg cells from Foxp3^Cre/+ and Foxp3^Cre/+Lkb1^f/f mice determined by transcriptional profiling, shown in groups based on their functions. Fold difference means fold change of gene expression levels in T_reg cells from Foxp3^CreLkb1^f/f mice compared with that from Foxp3^Cre mice. (f) Expression of indicated proteins on splenic T_reg cells from Foxp3^Cre/+ and Foxp3^Cre/+Lkb1^f/f mice (n=3). Two-way analysis of variance (ANOVA) was used for statistical analyses in (a, c, f) (*P<0.05, **P<0.01); error bars represent s.d.; all data are representative of at least two independent experiments.