Diversity of epitope and cytokine profiles for primary and secondary influenza A virus-specific CD8 T cell responses

Abstract

Screening with the flow cytometric IFN-γ assay has led to the identification of a new immunogenic peptide (SSYRRVPGI) from the influenza PB1 polymerase (PB1703-711) and a mimotope (ISPLMVAYM) from the PB2 polymerase (PB2198-206). CD8+ T cells specific for KbPB1703 make both IFN-γ and TNF-α following stimulation with both peptides. The CD8+ KbPB1703+ population kills PB2198-pulsed targets, but cell lines stimulated with PB2198 neither bind the KbPB1703 tetramer nor become CTL. This CD8+KbPB1703+ population is prominent in the primary response to an H3N2 virus, although it is much less obvious following secondary challenge of H1N1-primed mice. Even so, we can now account for >40% of the CD8+ T..