PAF-stimulated Th17 development is dependent on cytokines, LC-T cell contact and selected signaling pathways. (a) Monocyte-derived LC were stimulated with either vehicle or PAF in the presence of neutralizing Ab to IL-15, IL-6R, and/or IL-23, or control Ig, and cocultured with antiCD3/CD28-activated CD4+ T cells for 5 days. For comparison, CD4+ T cells were cultured alone with IL-1β, IL-6 and IL-23 for 5 days in the absence or presence of the above-indicated neutralizing Ab. RORγt expression was measured by FACS in CD4+ T cells and expressed as geometric mean (±SEM) fluorescence intensity (MFI). ; *; **; ***. (b) LC were stimulated with either vehicle or PAF and cocultured with antiCD3/CD28-activated CD4+ T cells for 5 days with direct LC-T cell contact or separated by a Transwell filter (LC in the top chamber, T cells in the bottom), in the absence or presence of neutralizing Ab to IL-6R or IL-23. RORγt expression was measured by FACS in CD4+ T cells and expressed as geometric mean (±SEM) fluorescence intensity (MFI). ; *; ***. (c) LC were stimulated with either vehicle or PAF and cocultured with antiCD3/CD28-activated CD4+ T cells for 5 days in the absence or presence of inhibitors of Jak2, EGFR, NF-κB, or STAT3. RORγt expression was measured by FACS in CD4+ T cells and expressed as geometric mean (±SEM) fluorescence intensity (MFI). ; **; ***.
