title: Structure and duration of contact between dendritic cells and T cells are controlled by T cell activation state.
abstract: The adaptive immune response is initiated when naive T cells interact with dendritic cells (DC). However, the physicodynamics as well as the molecules that constitute the contact plane (immunological synapse) between DC and T cells are not well understood. We show here that for the formation of stable conjugates, T cells need to be preactivated by DC in a CD80/86- and antigen dose-dependent manner. When activated, T cells induce cytoskeletal reorganization within DC via CD40-CD40L signaling. Polarization of the actin and fascin cytoskeleton in DC is associated with sustained DC-T cell contacts, strong T cell proliferation and a Th1 response. Organized contact planes with clearly separated patches containing TCR or CD11a are also formed. Thus, DC-T cell interactions take place in a sequential, interdependent fashion: first, DC "license" naive T cells to engage DC in an antigen dose- and CD80/86-dependent fashion. Then, these preactivated T cells induce cytoskeletal reorientation in DC, resulting in sustained DC-T cell contacts and subsequent T cell activation. These results demonstrate that T cells control the mode of interaction based on information gathered from DC.
authors.affiliation: Children's Hospital of the Ruhr-University-Bochum, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Rothoeft
authors.forename: Sandra
authors.initials: S
authors.lastname: Balkow
authors.forename: Mathias
authors.initials: M
authors.lastname: Krummen
authors.forename: Stefan
authors.initials: S
authors.lastname: Beissert
authors.forename: Georg
authors.initials: G
authors.lastname: Varga
authors.forename: Karin
authors.initials: K
authors.lastname: Loser
authors.forename: Pia
authors.initials: P
authors.lastname: Oberbanscheidt
authors.forename: Frank
authors.initials: F
authors.lastname: van den Boom
authors.forename: Stephan
authors.initials: S
authors.lastname: Grabbe
mesh_terms: D000818:Animals; D018122:B7-1 Antigen / Q000502:physiology; D051940:B7-2 Antigen / Q000235:genetics; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002450:Cell Communication / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D019169:Jurkat Cells; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D008822:Mice, Transgenic; D013997:Time Factors
chemical_list: D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse