Eric Champagne

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Many viruses, including retroviruses, are characterized by their specific cell tropism. Lymphadenopathy-associated virus (LAV) is a human lymphotropic retrovirus isolated from patients with acquired immune deficiency syndrome (AIDS) or related syndromes, that displays selective tropism for a subset of T lymphocytes defined by the expression of a surface(More)
The effect of high-density lipoprotein (HDL) in protecting against atherosclerosis is usually attributed to its role in 'reverse cholesterol transport'. In this process, HDL particles mediate the efflux and the transport of cholesterol from peripheral cells to the liver for further metabolism and bile excretion. Thus, cell-surface receptors for HDL on(More)
Mitochondrial ATP synthase has been recently detected at the surface of different cell types, where it is a high affinity receptor for apoA-I, the major protein component in high density lipoproteins (HDL). Cell surface ATP synthase (namely ecto-F₁-ATPase) expression is related to different biological effects, such as regulation of HDL uptake by(More)
Vgamma9Vdelta2 T lymphocytes, a major gammadelta T lymphocyte subset in humans, display cytolytic activity against various tumor cells upon recognition of yet uncharacterized structures. Here, we show that an entity related to the mitochondrial F1-ATPase is expressed on tumor cell surface and promotes tumor recognition by Vgamma9Vdelta2 T cells. When(More)
OBJECTIVE Several findings argue for a protective effect of high-density lipoproteins (HDLs) against endothelial dysfunction. The molecular mechanisms underlying this protective effect are not fully understood, although recent works suggest that the actions of HDL on the endothelium are initiated by multiple interactions between HDLs (lipid or protein(More)
Cell surface receptors for high-density lipoprotein (HDL) on hepatocytes are major partners in the regulation of cholesterol homeostasis. We recently identified a cell surface ATP synthase as a high-affinity receptor for HDL apolipoprotein A-I (apoA-I) on human hepatocytes. Stimulation of this ectopic ATP synthase by apoA-I triggered a(More)
We have previously demonstrated on human hepatocytes that apolipoprotein A-I binding to an ecto-F1-ATPase stimulates the production of extracellular ADP that activates a P2Y13-mediated high-density lipoprotein (HDL) endocytosis pathway. Therefore, we investigated the mechanisms controlling the extracellular ATP/ADP level in hepatic cell lines and primary(More)
PURPOSE OF REVIEW Until recently, F1Fo ATP synthase expression was believed to be strictly confined to mitochondria where it generates most cellular ATP. This paper reviews the recent evidence for an extra-mitochondrial expression of its components by immunofluorescence, biochemistry and proteomics studies. It discusses its possible implications in an(More)
Cell surface receptors for high-density lipoprotein (HDL) on hepatocytes are major partners in the regulation of cholesterol homeostasis. We have previously demonstrated on human hepatocytes that apolipoprotein A-I binding to an ectopic F(1)-ATPase stimulates the production of extracellular ADP that activates a P2Y(13)-mediated high-density lipoprotein(More)
Upon conjugation with cognate antigen-presenting cells (APCs), T lymphocytes undergo a sustained [Ca(2+)](i) increase resulting from the engagement of TCR and of accessory molecules with ligands expressed on the surface of APCs. We investigated the contribution of the accessory molecule CD2 to the activation of phospholipase Cgamma1 (PLCgamma1)/calcium(More)