Counting Antigen-Specific CD8 T Cells: A Reevaluation of Bystander Activation during Viral Infection
1998; Cell Press; Volume: 8; Issue: 2 Linguagem: Inglês
10.1016/s1074-7613(00)80470-7
ISSN1097-4180
AutoresKaja Murali‐Krishna, John D. Altman, M. Suresh, David Sourdive, Allan Zajac, Joseph D. Miller, Jill E. Slansky, Rafi Ahmed,
Tópico(s)Immunotherapy and Immune Responses
ResumoViral 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 × 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.
Referência(s)