Figure 3. Differential induction of the T cell-attracting chemokine CCL20 in DC stimulated by TLR4 and TLR5 ligands.

(A) DC generated from CD14⁺ precursors were stimulated with LPS (1µg/ml), flagellin (1µg/ml), or PBS for 14 h. Total RNA was isolated, and gene expression was profiled with GEArrayTM Q and S Series Kits (SuperArray Bioscience Corporation, Frederick, MD). Expression levels for selected genes in LPS- or flagellin-stimulated DC as compared to control DC are presented as a heat-map pattern. (B) CCL20-specific transcripts were quantified by qPCR in DC treated with LPS, flagellin, or PBS. Mean ± SEM from 6 experiments. (C) Monocyte-derived DC triggered with PBS, LPS, or flagellin were tested for their T cell-attracting capacity in a transwell assay system. Purified CD4 T cells (10⁵) were placed into the upper transwell inserts, and the insert was removed 2 h later. The number of CCR6⁺ CD4 T cells in the lower chamber was analyzed by FACS with FITC-conjugated mouse anti-human CD4 and PE-conjugated mouse anti-human CCR6 antibodies. Mean ± SEM from 8 independent experiments.