Differential polarization of C-terminal Src kinase between naive and antigen-experienced CD8+ T cells

J Immunol. 2013 Apr 1;190(7):3089-99. doi: 10.4049/jimmunol.1202408. Epub 2013 Feb 20.

Abstract

In CD8(+) T cells, engagement of the TCR with agonist peptide:MHC molecules causes dynamic redistribution of surface molecules including the CD8 coreceptor to the immunological synapse. CD8 associates with the Src-family kinase (SFK) Lck, which, in turn, initiates the rapid tyrosine phosphorylation events that drive cellular activation. Compared with naive T cells, Ag-experienced CD8(+) T cells make shorter contacts with APC, are less dependent on costimulation, and are triggered by lower concentrations of Ag, yet the molecular basis of this more efficient response of memory T cells is not fully understood. In this article, we show differences between naive and Ag-experienced CD8(+) T cells in colocalization of the SFKs and their negative regulator, C-terminal Src kinase (Csk). In naive CD8(+) T cells, there was pronounced colocalization of SFKs and Csk at the site of TCR triggering, whereas in Ag-experienced cells, Csk displayed a bipolar distribution with a proportion of the molecules sequestered within a cytosolic area in the distal pole of the cell. The data show that there is differential redistribution of a key negative regulator away from the site of TCR engagement in Ag-experienced CD8(+) T cells, which might be associated with the more efficient responses of these cells on re-exposure to Ag.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens / immunology*
  • CD8 Antigens / immunology
  • CD8 Antigens / metabolism
  • CD8-Positive T-Lymphocytes / enzymology*
  • CD8-Positive T-Lymphocytes / immunology*
  • CSK Tyrosine-Protein Kinase
  • Cells, Cultured
  • Enzyme Activation
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / metabolism
  • Mice
  • Mice, Knockout
  • Protein Transport
  • Proto-Oncogene Proteins c-fyn / metabolism
  • Receptors, Antigen, T-Cell / immunology
  • Receptors, Antigen, T-Cell / metabolism
  • src-Family Kinases / chemistry
  • src-Family Kinases / metabolism*

Substances

  • Antigens
  • CD8 Antigens
  • Receptors, Antigen, T-Cell
  • CSK Tyrosine-Protein Kinase
  • Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
  • Proto-Oncogene Proteins c-fyn
  • src-Family Kinases