mDC-independent protection from influenza. (a) Confocal imaging of ALN follicles at day 10 after UV-PR8 vaccination in WT and vG mice. Dashed line: B cell follicle. Images are representative of two independent trials; five mice/group. (b) ELISA analysis of PR8-specific serum antibodies at day 10 after UV-PR8 vaccination. Relative titers of PR8-specific IgM, IgG1, and IgG2b are shown. Symbols represent individual animals. (c) Unvaccinated or vaccinated WT or vG groups were challenged with LD80 PR8 21 d after vaccination. Morbidity (left) and mortality (right) are displayed as percentage of body weight or percent survival, respectively. Red dashed line: morbidity/euthanasia experimental cutoff. Six mice/group. (d) ELISA analysis of PR8-specific serum antibodies at day 9 after PR8 challenge as in c, compared with naive C57BL/6 littermates. Relative titers of PR8-specific IgM, IgG1, and IgG2b are shown. Symbols represent individual animals. *, P < 0.05; ***, P < 0.001. Mean ± SEM.