Establishment and first characterization of a sublingual epithelial and immune cell co-culture model

We describe here the establishment and first characterization of a co-culture model of human epithelial sublingual cells (HO-1-u-1 cell line) and human dendritic cells derived from human peripheral blood monocytes (PBMC). Cell culture conditions for HO-1-u-1 cells were optimized. First characterization of phenotypic features by electron microscopy and fluorescence imaging revealed resemblance to sublingual tissue specimen from healthy donors. Successful co-culturing of epithelial and dendritic cells (DCs) was confirmed by confocal laser scanning microscopy. Stimulation of HO-1-u1 cells alone and the epithelial/DC co-culture by incubation with liposomes, virosomes and influenza virus lead reproducibly to the release of inflammatory cytokine GM-CSF. This co-culture model may be suitable for elucidation of mechanisms involved in the immune response at the sublingual epithelium as well as for the evaluation of novel topical vaccines, potentially replacing cumbersome ex vivo and in vivo methods currently in place.