Trophoblast‐Derived Exosomes Mediate Monocyte Recruitment and Differentiation

Citation Atay S, Gercel‐Taylor C, Suttles J, Mor G, Taylor DD. Trophoblast‐derived exosomes mediate monocyte recruitment and differentiation. Am J Reprod Immunol 2011; 65: 65–77 Introduction Trophoblast cells have been demonstrated to regulate monocyte migration and differentiation, leading to pro‐inflammatory profiles. Because trophoblast cells release exosomes with immunoregulatory properties, trophoblast‐derived exosomes are proposed to ‘educate’ monocytes, creating a pro‐inflammatory environment. Method of study Exosomes were isolated from conditioned media of Swan71 cells by ultrafiltration and ultracentrifugation. Exosome‐induced migration was assessed using a two‐chamber system. Cytokine profiles were defined using cytokine arrays, and mRNA levels of affected cytokines were examined by qRT‐PCR and ELISA. Results Within 20 min, 8–10% of monocytes took up labeled exosomes isolated from Swan71 cells. Trophoblast‐derived exosomes increased monocyte migration in a dose‐dependent manner and produced significant increases in production of interleukin (IL)‐1β, IL‐6, Serpin‐E1, granulocyte colony‐stimulating factor, granulocyte/monocyte colony‐stimulating factor, and tumor necrosis factor‐α. Conclusion This study presents the initial demonstration that trophoblast‐derived exosomes are capable of recruiting and ‘educating’ monocytes to produce pro‐inflammatory cytokine/chemokine profiles in a cell‐contact‐independent manner.