Fig. 8

HA-VLP or HA-VLP-Cyt vaccination reduced inflammatory cytokines and induced T cell responses in the lung. Inflammatory cytokines and T cell responses were determined in lung tissues collected day 5 post challenge from aged BALB/c (A, B) and young (C, D) mice (n= 6/group) that were prime-boost immunized with 3 µg of HA-VLP or HA-VLP-Cyt. Inflammatory cytokines TNF-α, IFN-γ and IL-6 in lung lysates from aged mice after heterologous A/WSN challenge (A). IFN-γ-producing CD4⁺ T cells or CD8⁺ T cells specific for HA peptides and inactivated A/PR8 after intracellular staining were gated and quantified by flow cytometry from lung cells (B, D). Error bars indicate mean ± SEM. The statistical significances were determined using One-way ANOVA and Turkey's multiple comparison test and indicated in * P < 0.1; ** P < 0.01; *** P < 0.001