Skin application of the nonsteroidal anti-inflammatory drug ketoprofen downmodulates the antigen-presenting ability of Langerhans cells in mice.

Summary Background  Ketoprofen (KP) is widely used as a topical nonsteroidal anti-inflammatory drug that inhibits prostaglandin (PG) biosynthesis. As PGE2 upregulates the antigen-presenting activity of Langerhans cells (LCs), i.e. migration to lymph nodes and expression of immunocompetent molecules, modulation of LC functions resulting from topical application of KP is an issue to be clarified. Objectives  To investigate the in vivo effect of KP application to the skin and the in vitro effect of KP addition to the culture on the antigen-presenting ability of murine LCs. Methods  Ears of BALB/c mice were painted with picryl chloride (PCl) hapten, KP or both. An immunofluorescence study of epidermal sheets and a flow cytometric analysis of epidermal cell suspensions from the treated ears were performed. Results  PCl altered the morphology of LCs and reduced their number, and simultaneous application of 10% KP maintained LC morphology and number. KP at 5% or 10% clearly decreased the PCl-augmented expression of major histocompatibility complex class II and CD86 on LCs. In cultivation of freshly isolated epidermal cells, 5 mmol L−1 KP inhibited the culture-promoted expression of these molecules on LCs, whereas 100 μmol L−1 indomethacin was not inhibitory. The further addition of PGE2 to the KP-containing epidermal cell culture did not restore the expression of these molecules. Moreover, topical application of 10% KP to the sensitizing sites suppressed the development of contact hypersensitivity to PCl. Conclusions  KP may have the potential to inhibit the antigen-presenting ability of LCs, in a PGE2-independent manner.