T Cell Specific Adapter Protein (TSAd) Interacts with Tec Kinase ITK to Promote CXCL12 Induced Migration of Human and Murine T Cells

Tone Berge,Gunn B Holthe,Lena Claesson-Welsh,Thorny C B Andersen,Amy H Andreotti,Stine Granum,Anne Spurkland,Vibeke Sundvold-Gjerstad,Marit Inngjerdingen,Jean Kanellopoulos

doi:10.1371/journal.pone.0009761

Tone Berge, Gunn B Holthe + Show 8 more

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https://doi.org/10.1371/journal.pone.0009761

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Abstract

BackgroundThe chemokine CXCL12/SDF-1α interacts with its G-protein coupled receptor CXCR4 to induce migration of lymphoid and endothelial cells. T cell specific adapter protein (TSAd) has been found to promote migration of Jurkat T cells through interaction with the G protein β subunit. However, the molecular mechanisms for how TSAd influences cellular migration have not been characterized in detail.Principal FindingsWe show that TSAd is required for tyrosine phosphorylation of the Lck substrate IL2-inducible T cell kinase (Itk). Presence of Itk Y511 was necessary to boost TSAd's effect on CXCL12 induced migration of Jurkat T cells. In addition, TSAd's ability to promote CXCL12-induced actin polymerization and migration of Jurkat T lymphocytes was dependent on the Itk-interaction site in the proline-rich region of TSAd. Furthermore, TSAd-deficient murine thymocytes failed to respond to CXCL12 with increased Itk phosphorylation, and displayed reduced actin polymerization and cell migration responses.ConclusionWe propose that TSAd, through its interaction with both Itk and Lck, primes Itk for Lck mediated phosphorylation and thereby regulates CXCL12 induced T cell migration and actin cytoskeleton rearrangements.

Highlights

The CXC chemokine subfamily member, CXCL12/stromal cell-derived factor (SDF)-1a, is expressed in a broad range of tissues and has multiple effects on lymphoid and endothelial cells
We propose that T cell specific adapter protein (TSAd), through its interaction with both inducible T cell kinase (Itk) and Lck, primes Itk for Lck mediated phosphorylation and thereby regulates CXCL12 induced T cell migration and actin cytoskeleton rearrangements
Using Jurkat T cells as a model system, we show that the positive effect of TSAd on CXCL12 induced chemotaxis is dependent on its Itk interaction site and on an intact Itk Y511 phosphorylation site

Summary

Introduction

The CXC chemokine subfamily member, CXCL12/stromal cell-derived factor (SDF)-1a, is expressed in a broad range of tissues and has multiple effects on lymphoid and endothelial cells (reviewed in [1]). CXCL12 modulates T cell development in the thymus [4,5], T cell adhesion and migration [6], as well as expression of genes controlling T cell signaling, migration and survival [7]. These effects are mediated through multiple signaling pathways, including the Ras, ERK [8], the JAK/STAT [9] and the PI3K-1A and -1B pathways [10,11]. The chemokine CXCL12/SDF-1a interacts with its G-protein coupled receptor CXCR4 to induce migration of lymphoid and endothelial cells. The molecular mechanisms for how TSAd influences cellular migration have not been characterized in detail

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