The in vitro effect of retinol on human gingival epithelium. II. Modulation of Langerhans cell markers and interleukin-1 production.

The in vitro influence of retinol on the markers of gingival Langerhans cells (LC) was investigated using an organ culture system. Retinol at a dose of 5 micrograms/ml produced an increase in the density of T6-positive cells within the epithelium which peaked during the first 24 h of culture. LC HLA-DR and ATPase markers were maintained for the same period, while all markers were depressed after 72 h. These effects were not seen in explants cultured in conventional or alcohol-enriched media, in which all markers were lost in an exponential fashion. In addition to modulation of LC markers, retinol treatment also prolonged the expression of HLA-DR antigens by gingival keratinocytes. These findings, together with the augmented production of interleukin-1-like activity by retinol-treated gingival organ cultures suggest that low doses of retinol may alter immune reactions within epithelia via stimulation of both keratinocytes and LC.