Upregulation of interleukin-4 receptor by interferon-γ: Enhanced interleukin-4-induced eotaxin-3 production in airway epithelium

Airway epithelial cells produce a number of chemokines, including eotaxins. Among the three known eotaxins, T helper (Th) type 2 cytokines have been observed to induce the expression of eotaxin-3 mRNA. This study investigated the effect of interferon (IFN)-γ, a Th1 cytokine, on Th2 cytokine–induced eotaxin-3 production in a bronchial epithelial cell line, BEAS-2B. BEAS-2B cells produced eotaxin-3 after stimulation with the Th2 cytokines interleukin (IL)-13 and IL-4. When BEAS-2B cells were cultured with varying concentrations of IFN-γ for 24 h, dose-dependent inhibition of Th2 cytokine–induced eotaxin-3 mRNA expression and protein production was observed. This was associated with downregulation of signal transducer and activator of transcription 6 activation. On the other hand, 2-d pretreatment of BEAS-2B cells with IFN-γ dose-dependently enhanced Th2 cytokine–induced eotaxin-3 mRNA expression and production. IFN-γ also increased the mRNA expression and protein production of IL-4 receptor (R) α in a time-...