Exosomes from LPS and IFN-γ–matured BMDCs display higher expression of MHC II and CD80 molecules on their surface than exosomes from immature BMDCs. (A) Exosomes derived from immature, LPS, or IFN-γ–matured BMDCs were coated on aldehyde/sulfate latex beads, stained with a panel of PE- and FITC-conjugated specific (open histogram) and isotype-matched (solid histogram) antibodies, and then analyzed by flow cytometry. One representative experiment of 3 is displayed. (B) BMDC-derived exosomes have similar densities as previously reported for exosomes. Pelleted (100 000g) exosomes from immature, LPS, or IFN-γ–matured BMDCs were loaded on continuous sucrose density gradients and ultracentrifuged. Fractions were collected and directly analyzed by flow cytometry after coating on latex beads and staining with fluorochrome-conjugated antibodies against MHC II (grid histogram) and CD81 (open histogram).