Multifocal structure of the T cell - dendritic cell synapse

Eur J Immunol. 2005 Jun;35(6):1741-53. doi: 10.1002/eji.200425857.

Abstract

The structure of immunological synapses formed between murine naive T cells and mature dendritic cells has been subjected to a quantitative analysis. Immunofluorescence images of synapses formed in the absence of antigen show a diffuse synaptic accumulation of CD3 and LFA-1. In electron microscopy, these antigen-free synapses present a number of tight appositions (cleft size approximately 15 nm), all along the synapse. These tight appositions cover a significantly larger surface fraction of antigen-dependent synapses. In immunofluorescence, antigen-dependent synapses show multiple patches of CD3 and LFA-1 with a variable overlap. A similar distribution is observed for PKCtheta and talin. A concentric organization characteristic of prototypical synapses is rarely observed, even when dendritic cells are paralyzed by cytoskeletal poisons. In T-DC synapses, the interaction surface is composed of several tens of submicronic contact spots, with no large-scale segregation of CD3 and LFA-1. As a comparison, in T-B synapses, a central cluster of CD3 is frequently observed by immunofluorescence, and electron microscopy reveals a central tight apposition. Our data show that it is inappropriate to consider the concentric structure as a "mature synapse" and multifocal structures as immature.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD3 Complex / analysis
  • Cytoskeleton / physiology
  • Dendritic Cells / ultrastructure*
  • Fluorescent Antibody Technique
  • Intercellular Adhesion Molecule-1 / analysis
  • Lymphocyte Function-Associated Antigen-1 / analysis
  • Mice
  • Mice, Inbred C57BL
  • Microscopy, Electron
  • Synapses / ultrastructure*
  • T-Lymphocytes / ultrastructure*

Substances

  • CD3 Complex
  • Lymphocyte Function-Associated Antigen-1
  • Intercellular Adhesion Molecule-1