Figure 9.

Deletion or I6E mutation of vaccinia virus (VACV) N1 enhances the effector function of memory CD8⁺ T cells. Mice were infected intradermally with the indicated viruses and challenged intranasally 28 days post-infection with 5 × 10⁶ plaque-forming units of VACV WR. Lung or splenic lymphocytes were isolated 4 days later and the CD8⁺ T-cell populations were assayed by intracellular cytokine staining (ICS) for interferon-γ (IFN-γ) production. Data are presented as scatter plots (top panels) and as histograms indicating the percentage of IFN-γ⁺ CD8⁺ T cells (middle panels), or the absolute cell number of IFN-γ⁺ CD8⁺ T cells (bottom panels). *P < 0·05, **P < 0·001, n = 5. Results are expressed as mean ± SEM.