Human monocyte-derived dendritic cells expressing both chemotactic cytokines IL-8, MCP-1, RANTES and their receptors, and their selective migration to these chemokines.

OBJECTIVE: To characterize the mRNA expression of CXC chemokine IL-8, CC chemokine monocyte chemothractant protein-1 (MCP-1) and regulated on activation, normal T cell expressed and secreted (RANTES), and a newly defined DC chemokine DC-CK1 as well as the expression of IL-8 receptor, MCP-1 receptor and RANTES receptor in human monocyte-derived dendritic cells (MoDCs). The migratory responsiveness of MoDC to IL-8, MCP-1 and RANTES was also studied.
METHODS: In vitro generated MoDCs were obtained by differentiating monocytes in the presence of GM-CSF and IL-4 for 5 days. The time course of RNA expression was analyzed by RT-PCR and migratory ability was assessed by a micromultiwell chemotaxis chamber assay.
RESULTS: IL-8, MCP-1, RANTES and their corresponding receptors were consistently expressed in MoDCs. DC-CK-1 expression was detectable after 48 hours of differentiation. MoDC selectively migrated in response to MCP-1 and RANTES but not to IL-8 though transcripts of IL-8 receptor were present.
CONCLUSION: Because the capacity of dendritic cells to initiate immune responses depends on their specialized migratory and tissue homing properties, the expression of chemokines and their receptors along with the migratory responsiveness to chemokines of MoDC in our study suggests a potential role of chemokines in the interaction between dendritic cells and T cells and the induction of immune responses.