Transcriptional Control of Metabolism, Inflammation and the Immune Response: The Role of PPARs

Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors with key metabolic roles in adipose tissue, liver and skeletal muscle. They are also expressed at significant levels in polymorphonuclear cells, monocyte/ macrophages, dendritic cells, T cells and B cells, suggesting that they may have a role in modulating the immune response. To date, evidence for such a role comes from numerous studies describing changes in gene expression within immunoregulatory cells in response to pharmacological PPAR ligands, reports of beneficial effects of PPAR agonists in auto-immune disease in rodents, and accelerated auto-immune disease in genetically modified rodents with reduced PPAR expression. Coupled with the knowledge that the PPARs may act as "lipid sensors", these data have added to the growing scientific awareness of links between nutritional status and immune function.