TSLP effects on primary human blood dendritic cells

The ontogeny of human Langerhans cells (LCs) remains poorly characterized, in particular the nature of LC precursors and the factors that may drive LC differentiation. Through a systematic transcriptomic analysis of TSLP-activated dendritic cells (DCs), we unexpectedly identified markers that have been associated with a skin-homing potential as well as with a LC phenotype. We performed transcriptomic analysis of TSLP-activated blood DCs, as compared to freshly purified, Medium-, and TNF-activated DCs. Among TSLP up-regulated genes, we identified molecules associated with skin homing, LC phenotype, and LC function, as determined by a literature-based survey. Conversely, genes not expressed in LCs were not found among TSLP-induced genes. Further experiments showed that TGF-β synergized with TSLP leading to the differentiation of blood BDCA-1+ DCs into bona fide Birbeck granule-positive LCs. The ontogeny of human Langerhans cells (LCs) remains poorly characterized, in particular the nature of LC precursors and the factors that may drive LC differentiation. Through a systematic transcriptomic analysis of TSLP-activated dendritic cells (DCs), we unexpectedly identified markers that have been associated with a skin-homing potential as well as with a LC phenotype. We performed transcriptomic analysis of TSLP-activated blood DCs, as compared to freshly purified, Medium-, and TNF-activated DCs. Among TSLP up-regulated genes, we identified molecules associated with skin homing, LC phenotype, and LC function, as determined by a literature-based survey. Conversely, genes not expressed in LCs were not found among TSLP-induced genes. Further experiments showed that TGF-β synergized with TSLP leading to the differentiation of blood BDCA-1+ DCs into bona fide Birbeck granule-positive LCs. Dendritic cells (DC) were purified from the blood of healthy human donors. Each replicate comes from a different donor. There are 6 freshly purified samples (Control_0h), 4 DC samples cultured during 6h with no additional stimulus than the medium (Control_6h), 5 samples cultured during 6h with recombinant TSLP (Thymic Stromal Lymphopoietin at 20 ng/uL) (TSLP_6h) and 3 samples cultured during 6h with recombinant TNF (Tumor necrosis factor at 20 ng/mL) (TNF_6h).