In vivo significance of ITK-SLP-76 interaction in cytokine production

Mol Cell Biol. 2010 Jul;30(14):3596-609. doi: 10.1128/MCB.01657-09. Epub 2010 May 10.


In vitro data have suggested that activation of the inducible T-cell kinase (ITK) requires an interaction with the adaptor protein SLP-76. One means for this interaction involves binding of the ITK SH3 domain to the polyproline-rich (PR) region of SLP-76. However, the biological significance of this association in live cells and the consequences of its disruption have not been demonstrated. Here, we utilized a polyarginine-rich, cell-permeable peptide that represents the portion of the SLP-76 PR region that interacts with the ITK SH3 domain as a competitive inhibitor to disrupt the association between ITK and SLP-76 in live cells. We demonstrate that treatment of cells with this peptide, by either in vitro incubation or intraperitoneal injection of the peptide in mice, inhibits the T-cell receptor (TCR)-induced association between ITK and SLP-76, recruitment and transphosphorylation of ITK, actin polarization at the T-cell contact site, and expression of Th2 cytokines. The inhibition is specific, as indicated by lack of effects by the polyarginine vehicle alone or a scrambled sequence of the cargo peptide. In view of the role of ITK as a regulator of Th2 cytokine expression, the data underscore the significance of ITK as a target for pharmacological intervention.

Publication types

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

MeSH terms

  • Actins / metabolism
  • Adaptor Proteins, Signal Transducing / deficiency
  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Amino Acid Sequence
  • Animals
  • Binding, Competitive
  • Cytokines / biosynthesis*
  • Humans
  • Jurkat Cells
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism
  • Phosphoproteins / deficiency
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Protein Interaction Domains and Motifs
  • Protein-Tyrosine Kinases / metabolism*
  • Receptors, Antigen, T-Cell / metabolism
  • Signal Transduction
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism


  • Actins
  • Adaptor Proteins, Signal Transducing
  • Cytokines
  • Peptide Fragments
  • Phosphoproteins
  • Receptors, Antigen, T-Cell
  • SLP-76 signal Transducing adaptor proteins
  • Protein-Tyrosine Kinases
  • emt protein-tyrosine kinase