Counting antigen-specific CD8 T cells: A reevaluation of bystander activation during viral infection

Academic Article


  • Viral infections induce extensive T cell proliferation in vivo, but the specificity of the majority of the responding T cells has not been defined. To address this issue we used tetramers of MHC class I molecules containing viral peptides to directly visualize antigen-specific CD8 T cells during acute LCMV infection of mice. Based on tetramer binding and two sensitive assays measuring interferon-γ production at the single-cell level, we found that 50%-70% of the activated CD8 T cells were LCMV specific (2 x 107 virus- specific cells/spleen). Following viral clearance, antigen-specific CD8 T cell numbers dropped to 106 per spleen and were maintained at this level for the life of the mouse. Upon rechallenge with LCMV, there was rapid expansion of memory T cells, but after infection with the heterologous vaccinia virus there was no detectable change in the numbers of LCMV-specific memory CTL. Therefore, much of the CD8 T cell expansion seen during viral infection represents antigen-specific cells and warrants a revision of our current thinking on the size of the antiviral response.
  • Published In

  • Immunity  Journal
  • Digital Object Identifier (doi)

    Author List

  • Murali-Krishna K; Altman JD; Suresh M; Sourdive DJD; Zajac AJ; Miller JD; Slansky J; Ahmed R
  • Start Page

  • 177
  • End Page

  • 187
  • Volume

  • 8
  • Issue

  • 2