Importantly, when depletion of lung CD103+ DCs in langerin-DTR mice was followed by infection with PR8-OT-I, priming of OT-I CD8+ T cells in the dLN was severely reduced when compared with PR8-OT-I infected WT (Fig. 7A), similar to our observations in the C3−/− mice (Fig. 1C). Here, C3 is linked to infection.