PPARg regulated gene expression in human dendritic cells

In order to gain insights into how PPARg regulates different facets of dendritic cell (DC) differentiation, we sought to identify PPARg regulated genes and gene networks in monocyte-derived dendritic cells using global gene expression profiling. We employed an exogenous ligand activation approach using a selective PPARg ligand (rosiglitazone abbreviated as RSG). In addition, we have defined culture conditions in which human serum (HS) induces PPARg activation via a yet uncharacterized endogenous mechanism. We also compared the gene expression profile of developing dendritic cells obtained from patients harboring dominant negative mutations of the PPARg receptor (C114R and C131Y). Keywords: ligand response Monocytes were cultured for 6, 24 hours or 5 days with 500 U/ml IL-4 and 800 U/ml GM-CSF; cytokine treatment was repeated at day 3. Cells were obtained from 12 healthy individuals (6 biological replicates; the 6 and 24 hours samples were obtained from a single individual but the 5 days samples from a different one). Ligands were added at the beginning of differentiation. The 6 and 24 hours cells were treated with vehicle (DC) or 1 uM rosiglitazone (DC RSG), in the case of 5 day cultured cells 2.5 uM RSG was used. Cells were cultured in RPMI plus 10% FBS, in the case of DC4-DC6 cells were also cultured in human AB serum (DC HS). Finally we also obtained cells from patients harboring point mutations of the PPARg receptor (C114R and C131Y)