A tissue-engineered model of T-cell mediated oral mucosal inflammatory disease.

T-cell-mediated oral mucocutaneous inflammatory conditions including oral lichen planus (OLP) are common but development of new treatments aimed at relieving symptoms and controlling OLP progression are hampered by the lack of experimental models. Here, we developed a tissue-engineered oral mucosal equivalent (OME) containing polarised T-cells to replicate OLP pathogenesis. Peripheral blood CD4+ and CD8+ T-cells were isolated, activated and polarised into Th1 and cytotoxic T-cells (Tc). OME were constructed by culturing oral keratinocytes on an oral fibroblast-populated hydrogel to produce a stratified squamous epithelium. OME stimulated with IFN-γ and TNF-α or medium from Th1 cells caused increased secretion of inflammatory cytokines/chemokines. A model of T-cell-mediated inflammatory disease was developed by combining OME on top of a Th1/Tc-containing hydrogel, followed by epithelial stimulation with IFN-γ/TNF-α. T-cell recruitment towards the epithelium was associated with increased secretion of T-cell chemoattractants CCL5, CXCL9 and CXCL10. Histological assessment showed tissue damage associated with cleaved-caspase-3 and altered laminin-5 expression. Treatment with inhibitors directed against JAK, K_Ca3.1 channels or clobetasol in solution and/or via a mucoadhesive patch prevented cytokine/chemokine release and tissue damage. This disease model has potential to probe for mechanisms of pathogenesis or as a test platform for novel therapeutics or treatment modalities.