Roles of T cells in conferring protection after M2e5x VLP mucosal immunization.

<p><b>(A)</b> Body weight changes. <b>(B)</b> Lung viral titers at day 6 post infection are presented as egg-infectious titers. At six weeks after boost immunization with M2e5x VLP, immune mice (n = 4) were intravenously received with anti-CD4 (CD4X) or anti-CD8 (CD8X) depletion antibodies at– 2 days and +1 day of challenge. PBS was used as a control. All mice were challenged with a lethal dose of A/Phil (H3N2) (5×LD₅₀). Statistical significance was determined using one-way ANOVA or an unpaired two-tailed Student’s <i>t</i> test. Error bars are means ± SEM of concentration or ratios from individual animals. *, <i>P</i><0.05; ***, <i>P</i><0.001.