FIG 5.
MF59-adjuvanted CD4KO mice induce protective CD8+ T cell responses. (A) CD4KO mice immunized with the split vaccine plus MF59 were injected with an anti-CD8 monoclonal antibody (150 μg/mouse; clone 53-6.7) to deplete CD8+ T cells before virus challenge. Cells were harvested from blood samples of CD8-depleted mice 2 days after injection to determine CD8 depletion. CD4 and CD8 marker profiles from CD3+ gated T cells are shown. (B) Body weight changes of CD8-depleted CD4KO mice after virus infection. (C) Lung virus titers in embryonated chicken eggs at day 5 after infection. (D) Lung histopathology of CD8-depleted CD4KO mice at day 5 postinfection. (E) Inflammatory IL-6 and TNF-α cytokine levels in BALF and lung extracts at day 5 postinfection. Statistical significances were calculated by one-way ANOVA and Tukey's multiple-comparison test. *, P < 0.05; **, P < 0.01; ***, P < 0.001 (for comparisons between CD8-depleted and CD8-undepleted CD4KO mouse groups [n = 5]).