Flotillins promote T cell receptor sorting through a fast Rab5-Rab11 endocytic recycling axis

Nat Commun. 2019 Sep 26;10(1):4392. doi: 10.1038/s41467-019-12352-w.

Abstract

The targeted endocytic recycling of the T cell receptor (TCR) to the immunological synapse is essential for T cell activation. Despite this, the mechanisms that underlie the sorting of internalised receptors into recycling endosomes remain poorly understood. To build a comprehensive picture of TCR recycling during T cell activation, we developed a suite of new imaging and quantification tools centred on photoactivation of fluorescent proteins. We show that the membrane-organising proteins, flotillin-1 and -2, are required for TCR to reach Rab5-positive endosomes immediately after endocytosis and for transfer from Rab5- to Rab11a-positive compartments. We further observe that after sorting into in Rab11a-positive vesicles, TCR recycles to the plasma membrane independent of flotillin expression. Our data suggest a mechanism whereby flotillins delineate a fast Rab5-Rab11a endocytic recycling axis and functionally contribute to regulate the spatial organisation of these endosomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Membrane / metabolism*
  • Endocytosis*
  • Endosomes / metabolism*
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Jurkat Cells
  • Membrane Proteins
  • Microscopy, Confocal
  • Protein Transport
  • Receptors, Antigen, T-Cell / genetics
  • Receptors, Antigen, T-Cell / metabolism*
  • rab GTP-Binding Proteins / metabolism*
  • rab5 GTP-Binding Proteins / metabolism*

Substances

  • Membrane Proteins
  • Receptors, Antigen, T-Cell
  • flotillins
  • Green Fluorescent Proteins
  • rab11 protein
  • rab GTP-Binding Proteins
  • rab5 GTP-Binding Proteins