INTERFERON-GAMMA DIFFERENTIALLY REGULATES CD80 (B7-1) AND CD86 (B7-2 B70) EXPRESSION ON HUMAN LANGERHANS CELLS/

CD80 (B7-1) and CD86 (B7-2/B70) have recently been identified in cultu red human Langerhans cells (LCs), although their role and regulatory p roperties remain unclear. We present our comparison of the expression of the molecules, mRNAs and the function between CD80 and CD86 in huma n LCs treated by interferon gamma (IFN-gamma). We examined the regulat ory properties of CD80 and CD86 expression in human LCs pretreated wit h IFN-gamma. Flow cytometric analysis indicated that the mean fluoresc ence intensity of CD86 but not CD80 was enhanced. However, the percent age modulation of both CD80 and CD86 positive cells were significantly up-regulated in a dose-dependent manner, after 48-h culturing with IF N-gamma. The regulatory properties of CD80 and CD86 mRNA expressions i n human LC were studied using polymerase chain reaction methods. We fo und that both CD80 and CD86 mRNA of enriched LCs following IFN-gamma p retreatment for 12 h were higher than those without pretreatment. We h ave demonstrated that the primary allogeneic mixed epidermal cell-lymp hocyte reaction induced by human LCs treated by IFN-gamma increased in a dose-dependent manner. There was a 61.5% inhibition by anti-CD86 mo noclonal antibody and a 32.5% inhibition by anti-CD80 monoclonal antib ody. These data indicate that the CD80 and CD86 expression of human LC s may be differently regulated by IFN-gamma.