Figure 1

PI3K/Akt-inhibition upregulates GPNMB gene expression in human moDC. Immature moDC were generated in vitro with GM-CSF and IL-4 alone (4/GM) or with additional TKI (3 μM imatinib or 3 μM nilotinib) or inhibitors of signal transduction (300 nM Akt inhibitor MK2206 (Akt-inh.), 300 nM Erk inhibitor FR180204 (Erk-inh.), 100 nM PI3K inhibitor LY294002 (PI3K-inh.), 20 nM c-Raf inhibitor 553003 (c-Raf-inh.)) and analyzed for GPNMB expression. Exemplary results from at least three independent experiments using different donors are presented. (A) qRT-PCR analysis: relative level of GPNMB mRNA. The mean (±SD) of duplicate measurements is shown. (B, C) GPNMB protein level of CD209⁺ moDC (of three different donors) was analyzed by flow cytometry. Where indicated, maturation of moDC was induced by LPS. Data were analyzed using FlowJo software and Difference in Median Fluorescence Intensity (DMFI) of CD209⁺ cells is shown in the upper right quadrants. (D) Phenotypic changes of immature moDC in the absence (4/GM) or presence of nilotinib or Akt inhibitor were analyzed by flow cytometry. Double stainings were performed with monoclonal antibodies recognizing CD209, CD1a or CD14. DMFI of CD209⁺ cells is shown in the upper right quadrants.