Cross-talk between TCR and CCR7 signaling sets a temporal threshold for enhanced T lymphocyte migration

J Immunol. 2011 Dec 1;187(11):5645-52. doi: 10.4049/jimmunol.1101850. Epub 2011 Oct 31.

Abstract

Lymphocyte homing to, and motility within, lymph nodes is regulated by the chemokine receptor CCR7 and its two ligands CCL19 and CCL21. There, lymphocytes are exposed to a number of extracellular stimuli that influence cellular functions and determine the cell fate. In this study, we assessed the effect of TCR engagement on CCR7-mediated cell migration. We found that long-term TCR triggering of freshly isolated human T cells through CD3/CD28 attenuated CCR7-driven chemotaxis, whereas short-term activation significantly enhanced CCR7-mediated, but not CXCR4-mediated, migration efficiency. Short-term activation most prominently enhanced the migratory response of naive T cells of both CD4 and CD8 subsets. We identified distinct roles for Src family kinases in modulating CCR7-mediated T cell migration. We provide evidence that Fyn, together with Ca(2+)-independent protein kinase C isoforms, kept the migratory response of naive T cells toward CCL21 at a low level. In nonactivated T cells, CCR7 triggering induced a Fyn-dependent phosphorylation of the inhibitory Tyr505 of Lck. Inhibiting Fyn in these nonactivated T cells prevented the negative regulation of Lck and facilitated high CCR7-driven T cell chemotaxis. Moreover, we found that the enhanced migration of short-term activated T cells was accompanied by a synergistic, Src-dependent activation of the adaptor molecule linker for activation of T cells. Collectively, we characterize a cross-talk between the TCR and CCR7 and provide mechanistic evidence that the activation status of T cells controls lymphocyte motility and sets a threshold for their migratory response.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cell Separation
  • Chemotaxis, Leukocyte / immunology*
  • Flow Cytometry
  • Humans
  • Lymphocyte Activation / immunology
  • Receptor Cross-Talk / immunology*
  • Receptors, Antigen, T-Cell / immunology
  • Receptors, Antigen, T-Cell / metabolism*
  • Receptors, CCR7 / immunology
  • Receptors, CCR7 / metabolism*
  • Signal Transduction / immunology*
  • T-Lymphocytes / cytology
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism*

Substances

  • CCR7 protein, human
  • Receptors, Antigen, T-Cell
  • Receptors, CCR7