TLR3 Signaling Modulates Immunomodulatory Property of Human Periodontal Ligament Stem Cells

This study investigates the role of Toll-like receptor 3 (TLR3) signaling in the immunomodulatory properties of human periodontal ligament stem cells (PDLSCs). PDLSCs express TLR3 and, when activated by poly(I:C), show increased expression of interferon-gamma, IDO, and HLA-G, which are key molecules in immunomodulation. The study confirms that TLR3 activation occurs in the cytoplasmic endosome and that RNA silencing can abolish the effects of poly(I:C). Co-culture experiments with PBMCs reveal that poly(I:C)-treated PDLSCs inhibit PBMCs and upregulate FOXO3, indicating an enhanced immunosuppressive role. These findings suggest that TLR3 signaling in PDLSCs could be leveraged for stem cell therapy applications.