Publications by authors named "Florence Depontieu"

The MHC class II (MHCII) processing pathway presents peptides derived from exogenous or membrane-bound proteins to CD4+ T cells. Several studies have shown that glycopeptides are necessary to modulate CD4+ T cell recognition, though glycopeptide structures in these cases are generally unknown. Here, we present a total of 93 glycopeptides from three melanoma cell lines and one matched EBV-transformed line with most found only in the melanoma cell lines.

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Endocan expression is increasingly studied in various human cancers. Experimental evidence showed that human endocan, through its glycan chain, is implicated in various processes of tumor growth. We functionally characterize mouse endocan which is also a chondroitin sulfate proteoglycan but much less glycanated than human endocan.

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Insights gained from characterizing MHC-peptide-TCR interactions have held the promise that directed structural modifications can have predictable functional consequences. The ability to manipulate T cell reactivity synthetically or through genetic engineering might thus be translated into new therapies for common diseases such as cancer and autoimmune disorders. In the current study, we determined the crystal structure of HLA-DR4 in complex with the nonmutated dominant gp100 epitope gp10044-59, associated with many melanomas.

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Human vascular endocan is a proteoglycan exhibiting tumorigenic activity through both its glycan and protein cores. Endocan mRNA is identified as being one of the most significant molecular signatures defining a poor prognosis in lung, breast, kidney, prostate, and thyroid malignancies. The survival inversely correlates with endocan expression in tumor tissue from hepatocarcinoma, and in serum from lung cancer.

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Dysregulated protein phosphorylation is a hallmark of malignant transformation. Transformation can generate major histocompatibility complex (MHC)-bound phosphopeptides that are differentially displayed on tumor cells for specific recognition by T cells. To understand how phosphorylation alters the antigenic identity of self-peptides and how MHC class II molecules present phosphopeptides for CD4(+) T-cell recognition, we determined the crystal structure of a phosphopeptide derived from melanoma antigen recognized by T cells-1 (pMART-1), selectively expressed by human melanomas, in complex with HLA-DR1.

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The activation and recruitment of CD4(+) T cells are critical for the development of efficient antitumor immunity and may allow for the optimization of current cancer immunotherapy strategies. Searching for more optimal and selective targets for CD4(+) T cells, we have investigated phosphopeptides, a new category of tumor-derived epitopes linked to proteins with vital cellular functions. Although MHC I-restricted phosphopeptides have been identified, it was previously unknown whether human MHC II molecules present phosphopeptides for specific CD4(+) T cell recognition.

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Background: Endocan was originally described as a dermatan sulfate proteoglycan found freely circulating in the blood. Endocan expression confers tumorigenic properties to epithelial cell lines or accelerate the growth of already tumorigenic cells. This molecule is the product of a single gene composed of 3 exons.

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Purpose: We evaluated the expression of endocan, a soluble lung- and kidney-selective endothelial cell-specific dermatan sulfate proteoglycan, in non-small cell lung tumors compared with normal lung and studied the significance of high levels of circulating endocan in patients with non-small cell lung cancer.

Material And Methods: Endocan and vascular endothelial growth factor mRNA expression were evaluated by semiquantitative PCR in tumoral and nontumoral lung tissue samples from a first series of 24 patients submitted to curative surgery. Relationships between survival, time to tumor progression, and serum levels of endocan were evaluated in a second series of 30 previously untreated patients addressed for staging.

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Objectives: a) To evaluate in septic patients the blood levels of endocan, a circulating proteoglycan, which regulates leukocyte function-associated antigen-1/intercellular adhesion molecule-1 interactions in vitro; b) to determine whether endocan could be used as a diagnostic and prognostic marker in sepsis in the intensive care unit; and c) to study kinetics of endocan secretion by endothelial cells in vitro after stimulation by soluble mediators involved in sepsis.

Design: Prospective observational study.

Setting: Intensive care unit of the University Hospitals of Lille, France, and Geneva, Switzerland.

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Objectives: The aim of this study was to test whether peroxynitrite neutralizers would reduce peroxynitrite accumulation and improve myocardial contractile dysfunction and inflammation in endotoxin-treated rats.

Background: Release of endogenous proinflammatory cytokines such as tumor necrosis factor (TNF)-alpha in response to endotoxin is responsible for the production of large amounts of nitric oxide (NO), which may exert detrimental effects on the myocardium in animal models, isolated hearts, and isolated cardiac myocytes. Recent studies have indicated that many of the deleterious effects of NO are mediated by peroxynitrite, a powerful oxidant generated from a fast diffusion-limited reaction of NO and superoxide anion.

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Excessive activation of calpains has been implicated in the pathophysiology of inflammation, trauma, and ischemia reperfusion injury. Here, we investigated the effects of calpain inhibition on myocardial dysfunction and inflammation induced by endotoxin in rats. Rats were treated i.

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