Exosomes from TLR3 activated mesenchymal stem cells stimulate expansion of therapeutic keratinocytes in photoaging model 4818

Description Background Mesenchymal stem cell (MSC) exosomes have been demonstrated to possess therapeutic activities n a variety of inflammatory settings. Mechanisms of MSC exosome activity remain unclear. Materials and Methods Umbilical cord derived MSC were activated with Poly (IC) in the presence of various HDAC inhibitors. Exosomes were administered in an ultraviolet photoaging models intradermally. Modulation of dermal inflammation and cellular immune profiles was performed. Results and Discussion: Exosomes from TLR-3 activated MSC possessed superior healing activity as compared to control exosomes. Keratinocyte production of IL-10 and IL-35 was associated with activated exosome administration. Increase FoxP3 cells were observed in treated animals, with enhanced therapeutic effect observed in the presence of low dose interleukin-2. These data support development of TLR-3 stimulated MSC exosomes as therapeutic products in skin inflammation and aging.