Transendothelial migration of lymphocytes mediated by intraendothelial vesicle stores rather than by extracellular chemokine depots

Nat Immunol. 2011 Dec 4;13(1):67-76. doi: 10.1038/ni.2173.

Abstract

Chemokines presented by the endothelium are critical for integrin-dependent adhesion and transendothelial migration of naive and memory lymphocytes. Here we found that effector lymphocytes of the type 1 helper T cell (T(H)1 cell) and type 1 cytotoxic T cell (T(C)1 cell) subtypes expressed adhesive integrins that bypassed chemokine signals and established firm arrests on variably inflamed endothelial barriers. Nevertheless, the transendothelial migration of these lymphocytes strictly depended on signals from guanine nucleotide-binding proteins of the G(i) type and was promoted by multiple endothelium-derived inflammatory chemokines, even without outer endothelial surface exposure. Instead, transendothelial migration-promoting endothelial chemokines were stored in vesicles docked on actin fibers beneath the plasma membranes and were locally released within tight lymphocyte-endothelial synapses. Thus, effector T lymphocytes can cross inflamed barriers through contact-guided consumption of intraendothelial chemokines without surface-deposited chemokines or extraendothelial chemokine gradients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Chemokines / metabolism*
  • Endothelial Cells / drug effects
  • Endothelial Cells / metabolism*
  • GTP-Binding Protein alpha Subunits, Gi-Go / metabolism
  • Humans
  • Hyaluronan Receptors / metabolism
  • Integrins / metabolism
  • Lymphocytes / immunology*
  • Lymphocytes / metabolism
  • Lymphocytes / ultrastructure
  • Mice
  • Receptors, CCR2 / metabolism
  • Signal Transduction
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • T-Lymphocytes / ultrastructure
  • Transendothelial and Transepithelial Migration / immunology*
  • Transport Vesicles / metabolism*
  • Tumor Necrosis Factor-alpha / pharmacology
  • Vasculitis / immunology
  • Vasculitis / metabolism

Substances

  • Chemokines
  • Hyaluronan Receptors
  • Integrins
  • Receptors, CCR2
  • Tumor Necrosis Factor-alpha
  • GTP-Binding Protein alpha Subunits, Gi-Go