Mitochondrial dysfunction in CD47-mediated caspase-independent cell death: ROS production in the absence of cytochrome c and AIF release.

Gaël Roué (1) , Natacha Bitton (1) , Victor J Yuste (1) , Thomas Montange (1) , Manuel Rubio (2) , Frederic Dessauge (3) , Cécile Delettre (1) , Hélène Merle-Béral (4) , Marika Sarfati (2) , Santos A Susin (1)

1 ASI - Apoptose et Système Immunitaire
2 Laboratoire Immunorégulation
3 Signalisation immunoparasitaire
4 Service d'hématologie biologique [CHU Pitié-Salpêtrière]

Ligation of CD47 by its natural ligand thrombospondin (TSP), or cross-linking by CD47 antibodies, triggers caspase-independent cell death in normal and leukemic cells. This kind of cell death is characterised by the cytoplasmic events of apoptosis including externalisation of phosphatidylserines and mitochondria swelling. We report herein selective mitochondrial changes in CD47-dependent cell death of T cells. After T cell stimulation via CD47, a rapid mitochondrial transmembrane potential (deltapsi(m)) disruption is accompanied by the production of reactive oxygen species (ROS) and phosphatidylserine exposure. Surprisingly, mitochondrial dysfunction does not induce cytochrome c or AIF release. Moreover, the dying cells do not exhibit caspase-3 activation and display intact nuclei without any large-scale, or oligonucleosomal DNA fragmentation. We conclude that DeltaPsi(m) loss and ROS production are an early step in CD47-dependent killing and neither cytochrome c, nor AIF are implicated in this new cell death pathway.

Domains: Life Sciences [q-bio]; Biochemistry, Molecular Biology; Molecular biology

Gaël Roué, Natacha Bitton, Victor J Yuste, Thomas Montange, Manuel Rubio, et al.. Mitochondrial dysfunction in CD47-mediated caspase-independent cell death: ROS production in the absence of cytochrome c and AIF release.. Biochimie, 2003, 85 (8), pp.741-6. ⟨10.1016/S0300-9084(03)00129-9⟩. ⟨pasteur-00194712⟩