TGF-β1 reciprocally controls chemotaxis of human peripheral blood monocyte-derived dendritic cells via chemokine receptors

We examined the effect of TGF-beta 1 on the chemotactic migratory ability of human monocyte-derived dendritic cells (DCs). Treatment of immature DCs with TGF-beta 1 resulted in increased expressions of CCR-1, CCR-3, CCR-5, CCR-6, and CXC chemokine receptor-4 (CXCR-4), which were concomitant with enhanced chemotactic migratory responses to their ligands, RANTES (for CCR-1, CCR-3, and CCR-5), macrophage-inflammatory protein-3 alpha (MIP-3 alpha) (for CCR-6), or stromal cell-derived growth factor-1 alpha (for CXCR-4). Ligation by TNF-alpha resulted in down-modulation of cell surface expressions of CCR-1, CCR-3, CCR-5, CCR-6, and CXCR-4, and the chemotaxis for RANTES, MIP-3 alpha, and stromal cell-derived growth factor-1 alpha, whereas this stimulation up-regulated the expression of CCR-7 and the chemotactic ability for MIP-3 beta. Stimulation of mature DCs with TGP-beta 1 also enhanced TNF-alpha-induced down-regulation of the expressions of CCR-1, CCR-3, CCR-5, CCR-6, and CXCR-4 and chemotaxis to their respective ligands, while this stimulation suppressed TNF-alpha-induced expression of CCR-7 and chemotactic migratory ability to MIP-3 beta. Our findings suggest that TGF-beta 1 reversibly regulates chemotaxis of DCs via regulation of chemokine receptor expression.