Modulation of gingival Langerhans cell T6 antigen expression in vitro by interleukin 1 and an interleukin 1 inhibitor.

A human gingival organ culture system was used to test the hypothesis that interleukin 1 (IL-1) modulates the expression of the cortical thymocyte antigen T6 on Langerhans cells (LC). In cultures enriched with E. coli lipopolysaccharide, T6 expression peaked concurrently with supernatant IL-1 activity. Addition of exogenous IL-1 produced a dose dependent increase in LC T6 expression while not affecting the expression of the Class II antigens DR and DQ by LC. An IL-1 suppressor factor (ILS) was associated with the loss of T6 antigens which occurred in conventional organ cultures. ILS inhibited the thymocyte response to IL-1 and neutralized the effects of IL-1 on both thymocytes and LC. In isolation ILS depressed T6 expression by eliminating resting DR negative LC. This factor may act to regulative negatively, the action of IL-1 as has been suggested for IL-1 inhibitors of similar molecular weight.