DC-to-MC interactions culminate in DC protein transfer to MCs. Intravital imaging of DC^GFP/MC^RFP mouse ear skin (A) before and after DNFB, MIP. Bars, 50 µm. (B) MIP, 24 h after DNFB. Bar, 20 µm. (C) Fluorescence emission spectra of two separate intracellular regions in a single image z-plane of a GFP⁺RFP⁺MC. Bar, 5 µm. (D) Single z-plane imaging of GFP vesicle transfer (white arrowheads) from GFP⁺DC into RFP⁺MC 24 h after DNFB. Bars, 5 µm. Refers to Video 13. (E) Random analysis of GFP⁺RFP⁺ MCs before (n = 102) and after DNFB (n = 30, each). (F) Quantification of GFP⁺RFP⁺MCs at 24 h after DNFB focused on responsive lesions (n = 16). **, P < 0.01; ***, P < 0.001.