Abstract
We observed the effects of interferon (IFN) -γ and interleukin (IL) -4, a cytokine of Thl and Th2, on an antigen presenting cell using a human dendritic cell-like cell line, ELD-1, which we had established previously. The ELD-1 cell, in a mixed culture with a T cell, induces the production of IFN-γ by allo reaction. The activity was dependent on ICAM-1, IL-12 and the HLA-DR antigen, and it was inhibited by pre-treatment with IL-4 and aggravated by pre-treatment with IFN-γ. The change of IL-12 expression of the ELD-1 cell was determined by FAGS analysis which revealed that IL-12 increased each time after IL-4, IFN-γ and T cell treatments, respectively; however, when IFN-γpre-treated ELD-1 cells and T cells were mixed, a synergistic aggravation effect was observed, which became inhibitory after IL-4 treatment. Both ICAM-1 and HLA-DR were strengthened by IFN-γtreatment, and HLA-DR was also augmented further by the T cell addition. In contrast ICAM-1 inhibition and inhibition of the reaction by addition of the T cell were observed for IL-4. These data suggested that ELD-1 cells increased an ability to activate Thl cells during cross-talks with T cells in an IFN-γ dependent manner, and that IL-4 interfered with the cross-talks.
