title: Cutting edge: CCR4 mediates antigen-primed T cell binding to activated dendritic cells.
abstract: 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 ( approximately 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 < 0.01). In contrast to naive T cells, primed T cell arrest was largely inhibited by pertussis toxin, neutralization of the CC chemokine, macrophage-derived chemokine (CCL22), or by desensitization of the CCL22 receptor, CCR4. Our results demonstrate that DC-derived CCL22 induces rapid binding of activated T cells under dynamic conditions and that Ag-primed and naive T cells fundamentally differ with respect to chemokine-dependent binding to DC.
authors.affiliation: Dermatology Branch, National Cancer Institute, Bethesda, MD 20892, USA.
authors.forename: M
authors.initials: M
authors.lastname: Wu
authors.forename: H
authors.initials: H
authors.lastname: Fang
authors.forename: S T
authors.initials: ST
authors.lastname: Hwang
mesh_terms: D000818:Animals; D019013:CD40 Antigens / Q000502:physiology; D002450:Cell Communication; D002460:Cell Line; D054422:Chemokine CCL22; D019742:Chemokines, CC / Q000494:pharmacology; D003713:Dendritic Cells / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D054398:Receptors, CCR4; D019707:Receptors, Chemokine / Q000502:physiology*; D013601:T-Lymphocytes / Q000502:physiology*
chemical_list: D019013:CD40 Antigens; C515483:Ccl22 protein, mouse; C515355:Ccr4 protein, mouse; D054422:Chemokine CCL22; D019742:Chemokines, CC; D054398:Receptors, CCR4; D019707:Receptors, Chemokine