Fig 1: Demonstration of Antigen-Presenting Cell (APC) mobilization and activation by the Myo-P device loaded with huGM-CSF-secreting cells (MVX-2) in an ex vivo human skin model(A) Scheme of the experimental procedure. Myo-P devices (empty or with huGM-CSF-secreting cells) were subcutaneously implanted in Hyposkin models. Punch biopsies were sampled at Day 1, 3, 5 and 7 after implantation (only at Day 3 for the empty Myo-P).(B) Top view of the HypoSkin model. The arrow is pointing to the Myo-P device.(C) Prior to implantation, a 24-h release was performed to measure the huGM-CSF secretion by ELISA.(D) Digital maps showing the spatial organization of APCs at the implantation site at Day 3. The white dotted line indicates the location of the Myo-P/sham device. Populations of Langerin+ dermal DCs and Langerhans cells were found closer to the site of the Myo-P2 condition.(E) Heatmap of implantation site at Day 3 showing an induction of a population of Langerhans cells that express CD45+ CD1c- CD207+ pan-HLA+ CCR7+ CD40high CD80+ CD83high CD86−only in the GM-CSF treated condition.(F) Heatmap of implantation site at Day 3 showing an induction of a population of Langerin+ dermal dendritic cells that express CD45+ CD1c+ CD207+ pan-HLAmed CCR7med CD40med CD80− CD83med CD86−only in the MVX-2 treated condition.(G) Volcano plot representing the statistically significant DEGs at Day 3. Scatterplots showed the -log 10 of the false discovery rate (FDR) versus the log of magnitude of change (fold change). Upregulated genes are in blue, and downregulated genes are in red.(H) Immune cell type abundance at Day 1, 3, 5 and 7 in the GM-CSF treated condition (labeled MVX-2), and Day 3 in the control.See also Figures S1, S2, and Tables S4–S6.