Our purpose was to study the mechanisms that regulate the secretion of cytokines by Langerhans cells (LC). XS52 cells, which are a prototypic LClike line established from the epidermis of BALB/c mice, produced constitutively no detectable IL-10, IL-6, or TNFa. Upon Ag-specific interaction with the KLH-specific Thl clone HDK-1, XS52 cells accumulated substantial amounts of intracellular IL-1/3, IL-6, and TNFa (FACS), and they secreted each cytokine in relatively large amounts (ELISA). By contrast, incubation with HDK-1 cells alone or KLH alone caused no detectable cytokine production, indicating the requirement for both Ag and T cells. T cell-mediated secretion of each cytokine was inhibited, in a dose-dependent manner, by IL-4, IL-10, or TGF/3. Interferon-y (IFNy) also inhibited the secretion of IL-1/3 and IL-6, but not of TNFa. Among these four inhibitory cytokines, IL-10 was most potent, causing >50% inhibition at 1 ng/ml. Combinations of these four inhibitory cytokines produced additive, but not synergistic, effects. By contrast, none of 21 other cytokines affected cytokine secretion by the XS52 DC. We conclude that, during Ag presentation, responding T cells activate LC (and presumably other dendritic cells) to secrete IL-1/3, IL-6, and TNFa. Importantly, at the same time, the very same T cells have the capacity to regulate this event through the elaboration of IL-4, IL-10, TGF/3, and IFNy.
|Original language||English (US)|
|State||Published - Dec 1 1996|
ASJC Scopus subject areas
- Molecular Biology