FIGURE 5.

Schematic presentation of two immunosuppressive mechanisms driven by endometriotic tissue–derived exosomes. The endometriotic tissue, here presented by diagnostic micrographs stained for CD 10, estrogen receptor (ER), and vimentin (VIM), secretes exosomes carrying the NKG2D receptor ligands MICA/B and ULBP 1–3 and the proapoptotic ligands FasL and TRAIL. MICA/B and ULBP 1–3 carrying exosomes internalize the NKG2D receptor on NK cells and impair their cytotoxic ability. Exosomes carrying FasL and TRAIL induce apoptosis of activated immune cells. These mechanisms protect the endometriotic tissue from immune attack and allow its persistence at ectopic sites.