Figure 6. Interferon-γ (IFN-γ) or tumor necrosis factor-α (TNFα) production by influenza A virus (IAV)-specific lung CD8+ T-cells.

Lungs from mice infected with PR/8 and HK/X31 IAVs, as previously described in Figure 1, were homogenized and stimulated for 6 hrs with nucleoprotein (NP)_366–374 and polymerase (PA)_224–233 peptides, MHC Class I restricted PR/8 IAV epitopes. NP_366–374 or PA_224–233-specific cytokine-producing CD8+ T-cells were identified as CD3⁺ CD8⁺ CD4⁻ IFN-γ⁺ (A) or TNFα⁺ (B), . The frequencies of NP_366–374 or PA_224–233-specific lung CD8+ T-cells (C) were also determined in B6, MyD88^−/− and TLR7^−/− mice (expressed as the percentage of CD3+ T-cells). Values shown (A & B) are the % of IFN-γ⁺ or TNFα⁺ NP_366–374 or PA_224–233-specific CD8+ T-cells minus unstimulated background (expressed as the percentage of CD8+ T-cells). Bars are median values. *p<0.05 compared to NP_366–374 or PA_224–233-specific B6 lung CD8+ T-cells.