The release of microparticles by apoptotic cells and their effects on macrophages.

Published

Journal Article

Microparticles are small membrane vesicles released from the cell membrane by exogenous budding. To elucidate the interactions of microparticles with macrophages, the effect of microparticles released from Jurkat T cells on RAW 264.7 cells was determined. Microparticles were isolated by differential centrifugation, using FACS analysis with annexin V and cell surface markers for identification. Various inducers of apoptosis increased the release of microparticles from Jurkat cells up to 5-fold. The released microparticles were then cultured with RAW 264.7 cells. As shown by confocal microscopy and FACS analysis, RAW 264.7 macrophages cleared microparticles by phagocytosis. In addition, microparticles induced apoptosis in RAW 264.7 cells in a dose-dependent manner with up to a 5-fold increase of annexin V positive cells and 9-fold increase in caspase 3 activity. Cell proliferation as determined by the MTT test was also reduced. Furthermore, microparticles stimulated the release of microparticles from macrophages. These effects were specific for macrophages, since no apoptosis was observed in NIH 3T3 and L929 cells. These findings indicate that microparticles can induce macrophages to undergo apoptosis, in turn resulting in a further increase of microparticles. The release of microparticles from apoptotic cells may therefore represent a novel amplification loop of cell death.

Full Text

Duke Authors

Cited Authors

  • Distler, JHW; Huber, LC; Hueber, AJ; Reich, CF; Gay, S; Distler, O; Pisetsky, DS

Published Date

  • August 2005

Published In

Volume / Issue

  • 10 / 4

Start / End Page

  • 731 - 741

PubMed ID

  • 16133865

Pubmed Central ID

  • 16133865

International Standard Serial Number (ISSN)

  • 1360-8185

Digital Object Identifier (DOI)

  • 10.1007/s10495-005-2941-5

Language

  • eng

Conference Location

  • Netherlands