Figure 2.

Melanoma cell-derived sEVs transfer MHC class I and class II molecules to the surface of APCs. The sEVs from A375 cells were incubated with PE-labelled isotype (a) or anti-HLA-ABC antibodies (b,c), purified by centrifugation, and incubated overnight with healthy donor monocytes (HuMo; a,b) or THP-1 cells (c,d). The next day, the cells were stained with APC-labelled secondary anti-mouse antibodies to demonstrate the appearance of the transferred MHC/antibody complexes on the surface of the recipient cells. A negative control following the same procedure but lacking sEVs is shown in the left part of (b,c). (d) Transfer of PE-labelled anti-CD63 antibodies through sEVs, followed by staining with anti-mouse antibodies. The percentages of events in the four quadrants are indicated. The results of one representative experiment out of three are shown.