Figure 4: Properties of exosomes released from HIV-1-infected DCs. DCs were cultured in the presence of LPS/IFN? and exosome-free suspension of NL4-3Balenv for 48h. Differential centrifugation of the cell-free supernatants yielded a pellet containing exosomes and HIV virions, which were analyzed by Western blotting for the indicated exosome markers (a). Results shown are representative of five experiments. AChE activity carried by exosomes is also shown (b). Data are expressed as the ratio of AChE activity relative to the mock condition and represent the mean ± SEM of three experiments..