Presentation of exosomal allopeptides by splenic CD8α⁺ DCs. (A) Thirty-six hours after intravenous injection of unlabeled allogeneic exosomes (BALB/c), splenic DCs (CD11c⁺, green) expressing IA^b-IEα_52-68 detected by Y-Ae mAb (red or yellow due to overlapping, arrows and inset) were detected in T-cell areas, defined by the lack of B220 staining (blue). (B) Percentage of splenic DCs (B10) with surface IA^b-IEα_52-68 36 hours after intravenous injection of allogeneic exosomes (BALB/c). (C) Presentation of IA^b-IEα_52-68 to 1.3H1 T cells by different subsets of splenic DCs of B10 mice, 36 hours after intravenous administration of allogeneic exosomes (BALB/c). Data are representative of 3 independent experiments and displayed as their means ± SD.