Diacylglycerol kinase zeta negatively regulates CXCR4-stimulated T lymphocyte firm arrest to ICAM-1 under shear flow

Integr Biol (Camb). 2012 Jun;4(6):606-14. doi: 10.1039/c2ib00002d. Epub 2012 May 1.

Abstract

T lymphocyte arrest within microvasculature is an essential process in immune surveillance and the adaptive immune response. Integrins and chemokines coordinately regulate when and where T cells stop under flow via chemokine-triggered inside-out activation of integrins. Diacylglycerol kinases (DGKs) regulate the levels of diacylglycerol (DAG) which in turn determine the activation of guanine nucleotide exchange factors (GEFs) and Ras proximity 1 (Rap1) molecules crucial to the activation of integrin lymphocyte function-associated antigen 1 (LFA-1). However, how the level of DGK regulates chemokine-stimulated LFA-1-mediated T cell arrest under flow is unknown. Using a combination of experiment and computational modeling, we demonstrate that DGKζ is a crucial regulator of CXCL12-triggered T cell arrest on surfaces presenting inter-cellular adhesion molecule 1 (ICAM-1). Using flow chamber assays, we found that the deficiency of DGKζ in T cells significantly increased firm arrest to ICAM-1-coated substrates and shortened the time to stop without altering the rolling velocity. These results suggest that DGKζ levels affect LFA-1-mediated T cell firm arrest, but not P-selectin-mediated rolling during CXCL12 stimulation. We accurately simulated the role of DGKζ in firm arrest of T cells computationally using an Integrated-Signaling Adhesive Dynamics (ISAD). In the absence of DGK catalytic reaction, the model cells rolled for a significantly shorter time before arrest, compared to when DGK molecules were present. Predictions of our model for T cell arrest quantitatively match experimental results. Overall these results demonstrate that DGKζ is a negative regulator of CXCL12-triggered inside-out activation of LFA-1 and firm adhesion of T cells under shear flow.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptive Immunity / immunology
  • Animals
  • Cell Adhesion / physiology
  • Computer Simulation
  • Diacylglycerol Kinase / deficiency
  • Diacylglycerol Kinase / immunology
  • Diacylglycerol Kinase / metabolism*
  • Intercellular Adhesion Molecule-1 / immunology
  • Intercellular Adhesion Molecule-1 / metabolism*
  • Lymphocyte Function-Associated Antigen-1 / immunology
  • Lymphocyte Function-Associated Antigen-1 / metabolism
  • Mice
  • Mice, Knockout
  • Microscopy, Phase-Contrast
  • Models, Biological
  • Receptors, CXCR4 / immunology
  • Receptors, CXCR4 / metabolism*
  • Signal Transduction
  • T-Lymphocytes / cytology
  • T-Lymphocytes / enzymology*
  • T-Lymphocytes / immunology

Substances

  • CXCR4 protein, mouse
  • Lymphocyte Function-Associated Antigen-1
  • Receptors, CXCR4
  • Intercellular Adhesion Molecule-1
  • Diacylglycerol Kinase
  • diacylglycerol kinase zeta, mouse