Red blood cells upregulate cytoprotective proteins and the labile iron pool in dividing human T cells despite a reduction in oxidative stress

Research output: Contribution to journalArticle

Abstract

We have recently reported that red blood cells (RBC) promote T cell growth and survival by inhibiting activation-induced T cell death. In the present study, we have examined parameters of oxidative stress and intracellular iron in activated T cells and correlated these data with the expression of ferritin, heme oxygenase-1 (HO-1), and the transferrin receptor CD71. T cells growing in the presence of RBC had reduced levels of reactive oxygen species (ROS) and oxidatively modified proteins, suggesting that RBC efficiently counteracted ROS production on the activated T cells. Flow cytometry and immunodetection demonstrated that T cells dividing in the presence of RBC had increased levels of intracellular ferritin rich in L-subunits and HO-1 along with a downmodulation in CD71 expression. Finally, using the fluorescent iron indicator calcein and flow cytometry analysis, we were able to show that a relative amount of the labile iron pool (LIP) was upregulated in T cells growing in the presence of RBC. These findings are consistent with a typical response to iron overload. However, neither heme compounds nor ferric iron reproduced the levels of expansion and survival of T cells induced by intact RBC. Altogether, these data suggest that RBC inhibit apoptosis of activated T cells by a combination of ROS scavenging and upregulation of cytoprotective proteins such as ferritin and HO-1, which may counteract a possible toxic effect of the increased intracellular free iron.

Details

Authors
External organisations
  • Institute for Molecular and Cell Biology
Research areas and keywords

Keywords

  • Apoptosis, Ferritin, Free radicals, Growth, Heme oxygenase, Iron, Oxidative stress, Red blood cells, Survival, T cells, Transferrin receptor
Original languageEnglish
Pages (from-to)1404-1416
Number of pages13
JournalFree Radical Biology and Medicine
Volume35
Issue number11
Publication statusPublished - 2003 Dec 1
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes