Ferulic Acid Induces Th1 Responses by Modulating the Function of Dendritic Cells and Ameliorates Th2-Mediated Allergic Airway Inflammation in Mice

Figure 4

Ferulic acid-modulated dendritic cells enhanced T-cell proliferation and Th1 cell polarization. (a) Modulatory effects of FA on T-cell proliferation. DCs were treated with medium, LPS (1 μg/mL), or LPS plus FA (400 μM) for 24 h. Allogeneic naïve CD4⁺ T cells (2 × 10⁵ cells/well) were cocultured with different proportions of γ-irradiated immature DCs, LPS-pulsed DCs, or LPS plus FA-treated DCs at DC/T-cell ratios of 1 : 5, 1 : 10, 1 : 20, and 1 : 40 in 96-well round-bottomed plates. After 2 days of culture, cells were pulsed with 1 μCi/well of [³H]-thymidine for 16~18 h. Specific incorporation of [³H]-thymidine was determined with a β-counter, and results are expressed as counts per minute (cpm). (b) Modulatory effects of FA on T-cell cytokine secretion. Concentrations of IFN-γ and IL-5 secreted by naïve CD4⁺ T cells, which were cocultured with γ-irradiated DCs in 96-well plates for 2 days, were determined by an ELISA. Results in all panels are expressed as the mean ± SEM of three independent experiments. ^#, ^##, and ^### versus medium-treated DCs. , , and versus LPS-treated DCs.

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