Modulation of Class II (DR and DQ) antigen expression on gingival Langerhans cells in vitro by gamma interferon and prostaglandin E2

The effect of human and murine gamma interferon (IFN-gamma) on Class II (DR and DQ) expression by human gingival Langerhans cells (LC) was examined using an organ culture system. Human and murine IFN-gamma increased the expression of both DR and DQ antigens during a 72-h period. Maximal levels of DR expression (100% of T6+ cells) were produced within 6 h of IFN-gamma treatment and were maintained during culture. DQ expression was maximal (100% of T6+ cells) at 18 h and was more labile than DR. The effect of IFN-gamma on DR and DQ was abrogated by prostaglandin E2 (PGE) while indomethacin, and inhibitor of PGE synthesis, mimicked the effect of IFN-gamma on DR and DQ expression. Gingival keratinocytes maintained their expression of DR for 72 h in the presence of gamma-IFN, but did not express DQ under any of the culture conditions used in this study. These results demonstrate that gamma-IFN induces differential expression of Class II antigens in the oral mucosa in vitro, and suggest that gamma-IFN and PGE may be involved in the control of DR and DQ antigen expression in vivo.