Cutting Edge: CCR4 Mediates Antigen-Primed T Cell Binding to Activated Dendritic Cells

The binding of a T cell to an Ag-laden dendritic cell (DC) is a critical step of the acquired immune response. Herein, we address whether a DC-produced chemokine can induce the arrest of T cells on DC under dynamic flow conditions. Ag-primed T cells and a T cell line were observed to rapidly (∼0.5 s) bind to immobilized DC at low shear stress (0.1–0.2 dynes/cm 2 ) in a pertussis toxin-sensitive fashion. Quantitatively, Ag-primed T cells displayed 2- to 3-fold enhanced binding to DC compared with unprimed T cells ( p