Giorgio Berton

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The aim of the present study was to investigate the role of tyrosine phosphorylation pathways in fMLP-induced exocytosis of the different secretory compartments (primary and secondary granules, as well as secretory vesicles) of neutrophils. Genistein, a broad specificity tyrosine kinase inhibitor, blocked the exocytosis of primary and secondary granules,(More)
Cross-linking of the neutrophil-beta 2- or beta 3-related leukocyte response integrins by extracellular matrix (ECM) proteins or monoclonal antibodies (mAb) stimulates cytoskeletal rearrangement leading to cell spreading and respiratory burst. Tyrosin phosphorylation of a variety of proteins and activation of the Src family kinases within polymorphonuclear(More)
Polymorphonuclear neutrophils (PMN) adherent to integrin ligands respond to inflammatory mediators by reorganizing their cytoskeleton and releasing reactive oxygen intermediates. As Src family tyrosine kinases are implicated in these responses, we investigated their possible role in regulating degranulation. Human PMN incubated on fibrinogen released(More)
Ikaros plays an important role in the control of differentiation and proliferation of all lymphoid lineages. The expression of short isoforms lacking DNA-binding motifs alters the differentiation capacities of hematopoietic progenitors, arresting lineage commitment. We sought to determine whether molecular abnormalities involving the IKZF1 gene were(More)
The angiogenic activity of CXC-ELR(+) chemokines, including CXCL8/IL-8, CXCL1/macrophage inflammatory protein-2 (MIP-2), and CXCL1/growth-related oncogene-alpha in the Matrigel sponge angiogenesis assay in vivo, is strictly neutrophil dependent, as neutrophil depletion of the animals completely abrogates the angiogenic response. In this study, we(More)
Src family kinases are implicated in signaling by integrins in polymorphonuclear neutrophils (PMN). To identify proteins present in complexes with Src family kinases, we subjected p58(c-fgr) or p53/56(lyn) immunoprecipitates from Triton X-100 lysates of PMN incubated on fibrinogen-coated surfaces to in vitro kinase assays. Assays on p58(c-fgr) or(More)
Stimulation of adherent human neutrophils (PMN) with tumor necrosis factor (TNF) triggers protein tyrosine phosphorylation (Fuortes, M., W. W. Jin, and C. Nathan. 1993. J. Cell Biol. 120:777-784). We investigated the dependence of this response on beta 2 integrins by using PMN isolated from a leukocyte adhesion deficiency (LAD) patient, which do not express(More)
Src-family kinases and Syk tyrosine kinases have crucial roles in multiple leukocyte intracellular signaling pathways. In immunoreceptor-related pathways, these enzymes work together sequentially, with Src-family kinases phosphorylating specific protein substrates, which in turn recruit and activate Syk. Recent evidence indicates that several(More)
Sulfatides have been established recently as ligands for L-selectin, and we investigated whether they trigger transmembrane signals through ligation of L-selectin. We found that sulfatides trigger the increase of cytosolic free calcium in neutrophils and that this effect was strictly dependent on sulfation of the galactose ring, as non-sulfated(More)
To address the question whether leukocyte integrins are able to generate signals activating neutrophil functions, we investigated the capability of mAbs against the common beta chain (CD18), or the distinct alpha chains of CR3, LFA-1, or gp150/95, to activate neutrophil respiratory burst. These investigations were performed with mAbs bound to protein A(More)