Supplementary Figure 8: PTEN expression and immune dysregulation in Pten^fl/+Foxp3-Cre mice and the model describing PTEN signaling in T_reg cells.

(a,b) Analysis of Pten mRNA (a) and protein (b) expression in T_reg, naive CD4⁺ (CD62L⁺CD44⁻), and CD8⁺ T cells from WT and Pten^fl/+Foxp3-Cre mice. Numbers below the PTEN lanes indicate band intensity relative to that of β-actin (b). (c) Immunofluorescence of spleen sections of WT and Pten^fl/+Foxp3-Cre mice for the staining of CD3 (red) and PNA (green) (scale bars, 60 μm). Right, quantification of germinal center area. (d) Images of peripheral lymph nodes from WT and Pten^fl/+Foxp3-Cre mice (~5 months old) with lymphoproliferative disease. Data are representative of two independent experiments (a-d). *P < 0.001. Data are mean ± s.e.m. (e) Schematics of PTEN signaling in T_reg cell functions and immune tolerance. Loss of PTEN in T_reg cells dysregulates mTORC2 signaling and metabolic and transcriptional programs, leading to the disrupted stability of T_reg cells (as evidenced by the downregulation of CD25 expression, as well as other abnormalities not depicted here). Associated with loss of T_reg cell stability and the ensuing T_H1 responses and IFN-γ production is the aberrant induction of T_FH responses, spontaneous formation of germinal center responses, and development of autoimmune and lymphoproliferative disease.