Avid Bioservices Inc (CDMO)

[jazzbeerman]

T cell exosomes induce cholesterol accumulation in human monocytes via phosphatidylserine receptor.

J Cell Physiol. 2007 Jul

Zakharova L, Svetlova M, Fomina AF.


Department of Physiology and Membrane Biology, University of California Davis, Davis, California 95616, USA.


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-alpha 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.


--------



I suppose this could have something to do with the increase in atheroslerosis in HIV patients..

(when you consider the devastation wreaked on CD4 T cells in early HIV infection),


j