Peroxisome proliferator‐activated receptor γ activators inhibit interleukin‐12 production in murine dendritic cells

Abstract

Peroxisome proliferator‐activated receptors (PPARs) are members of the nuclear receptor superfamily. They are divided into three subtypes (α, β or δ, and γ) and are involved in lipid and glucose homeostasis and in the control of inflammation. In this study, we analyzed the expression of PPARs in murine dendritic cells (DCs), the most potent antigen presenting cells. We find that immature as well as mature spleen‐derived DCs express PPARγ, but not PPARα, mRNA and protein. We also show that the PPARγ activator rosiglitazone does not interfere with the maturation of DCs in vitro nor modifies their ability to activate naive T lymphocytes in vivo. Finally, we present evidence that PPARγ activators down‐modulate the CD40‐induced secretion of interleukin‐12, a potent Th1‐driving factor. These data suggest a possible role for PPARγ in the regulation of immune responses.