Uptake of exosomes does not interfere with splenic DC maturation in vivo. (A) Allogeneic exosomes (BALB/c) were injected intravenously into B10 recipients, and expression of IA^b, CD86, and CD54 was assessed in splenic CD8α^neg and CD8α⁺ splenic DCs 24 hours later. Capture of circulating exosomes did not induce activation of splenic DCs and did not interfere with CD40-induced DC activation (thick line histograms) compared to splenic DCs from controls (gray histograms). White histograms represent isotype controls. Data are representative of 2 independent experiments with 3 animals per group. (B) Quantitative analysis of mRNA cytokine gene expression of BMDCs was performed 4 hours (not shown) and 16 hours (b) following interaction with exosomes. (C) Densitometric analysis of each lane was expressed relative to corresponding housekeeping gene transcripts (L32). Data are representative of 2 independent experiments and displayed as their means ± SD.