FIGURE 8.

NOTCH1-PI3K signaling axis regulates TLR2-, NOD1-, and NOD2-triggered maturation rescue of human DCs. A–C, pretreatment of DC with GSI-I (γ-secretase inhibitor) (A) or LY294002 (B and C) abolishes Rv0754-, MDP-, and C12-iE-DAP-induced phosphorylation of GSK-3β (pGSK-3β) in DCs under CTLA-4-induced (B) or TGF-β-induced (A and C) immunosuppressive conditions. D and E, abrogation of NOTCH1 signaling by transfecting human DCs with NOTCH1 siRNA at a final concentration of 100 nm inhibit PI3K pathway activation under either CTLA-4-mediated (D) or TGF-β-mediated (E) suppressive conditions. PI3K pathway activation was assayed by phosphorylation of p85 using Western blotting. Blots are representative of three separate experiments. F and G, LY294002 or rapamycin inhibits Rv0754-, MDP-, and C12-iE-DAP-induced maturation of human DCs under CTLA-4-induced (F) or TGF-β-induced (G) immunosuppression. The immunoblots represent three independent experiments, and data in bar diagrams are represented as means ± S.E. from three independent donors. *, p < 0.05 versus CTLA-4 and MDP-C12-iE-DAP-Rv0754 or TGF-β and MDP-C12-iE-DAP-Rv0754.