Activated T lymphocytes release vesicles, termed exosomes, enriched in cholesterol and exposing phosphatidylserine (PS) at their outer membrane leaflet. Although CD4+ activated T lymphocytes infiltrate an atherosclerotic plaque, the effects of T cell exosomes on the atheroma-associated cells are not known. We report here that exosomes isolated from the supernatants of activated human CD4+ T cells enhance cholesterol accumulation in cultured human monocytes and THP-1 cells. Lipid droplets found in the cytosol of exosome-treated monocytes contained both cholesterol ester and free cholesterol. Anti-phosphatidylserine receptor antibodies recognized surface protein on the monocyte plasma membrane and prevented exosome-induced cholesterol accumulation, indicating that exosome internalization is mediated via endogenous phosphatidylserine receptor. The production of proinflammatory cytokine TNF-α enhanced in parallel with monocyte cholesterol accumulation. Our data strongly indicate that exosomes released by activated T cells may represent a powerful, previously unknown, atherogenic factor. © 2007 Wiley-Liss, Inc.
CITATION STYLE
Zakharova, L., Svetlova, M., & Fomina, A. F. (2007). T cell exosomes induce cholesterol accumulation in human monocytes via phosphatidylserine receptor. Journal of Cellular Physiology, 212(1), 174–181. https://doi.org/10.1002/jcp.21013
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