Description
IL-17A is a pro-inflammatory cytokine that promotes host defense against infections and contributes to the pathogenesis of chronic inflammatory diseases. Dendritic cells (DC) are antigen-presenting cells responsible for adaptive immune responses. Here, we report that IL-17A induces intense remodeling of lipid metabolism in human monocyte-derived DC, as revealed by microarrays analysis. In particular NR1H3/LXR-a and its target genes were significantly upregulated in response to IL-17A. IL-17A induced accumulation of Oil Red O-positive lipid droplets in DC leading to the generation of lipid-laden DC. A lipidomic study established that all the analyzed lipid species, i.e phospholipids, cholesterol, triglycerides, cholesteryl esters were elevated in IL-17A-treated DC. The increased expression of membrane lipid transporters in IL-17A-treated DC as well as their enhanced ability to uptake the fatty acid Bodipy-FL-C16 suggested that lipid uptake was the main mechanism responsible for lipid accumulation in response to IL-17A. IL-17A-induced lipid laden DC were able to stimulate allogeneic T cell proliferation in vitro as efficiently as untreated DC, indicating that IL-17A-treated DC are potently immunogenic. This study, encompassed in the field of immunometabolism, points out for the first time IL-17A as a modulator of lipid metabolism in DC and provides a rationale to delineate the importance of lipid-laden DC in IL-17A-related inflammatory diseases.