Hassen Kared

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Accumulating evidence that granulocyte colony-stimulating factor (G-CSF), the key hematopoietic growth factor of the myeloid lineage, not only represents a major component of the endogenous response to infections, but also affects adaptive immune responses, prompted us to investigate the therapeutic potential of G-CSF in autoimmune type 1 diabetes.(More)
Loss of CD4 T cell help correlates with virus persistence during acute hepatitis C virus (HCV) infection, but the underlying mechanism(s) remain unknown. We developed a combined proliferation/intracellular cytokine staining assay to monitor expansion of HCV-specific CD4 T cells and helper cytokines expression patterns during acute infections with different(More)
Cellular interactions promoting the in vivo expansion of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells for maintenance of immune tolerance remain poorly defined. Here we report that mobilized Lin(-)Sca-1(+)c-kit(+) (LSK) hematopoietic progenitor cells (HPCs), unlike medullary hematopoietic stem cells (HSCs), selectively drove the direct, immediate(More)
Activation of hepatic stellate cells (HSCs) is a key event in the initiation of liver fibrosis, characterized by enhanced extracellular matrix production and altered degradation. Activation of HSCs can be modulated by cytokines produced by immune cells. Recent reports have implicated the proinflammatory cytokine IL-17A in liver fibrosis progression. We(More)
HIV type 1 infection is associated with a rapid depletion of Th17 cells from the GALT. The chemokine receptor CCR6 is a marker for Th17 lineage polarization and HIV permissiveness in memory CD4(+) T cells. CCR6(+) T cells have the potential to migrate into the GALT via the gut-homing integrin α(4)β(7), a newly identified HIV-gp120 binding receptor. In this(More)
IL-17 is a potent effector cytokine involved in inflammatory response and antimicrobial defense. We report that SIV infection of rhesus macaques (RMs) results in the emergence of IL-17-expressing cells during the acute phase. This subpopulation appears at day 14 postinfection concomitantly with an increase in TGF-beta and IL-18 expression. This subset,(More)
In recent years, several investigators have unraveled a previously unrecognized role for G-CSF in the regulation of T cell and dendritic cell functions. The experimental evidence in favor of G-CSF-mediated immune regulation includes the ability to switch T cell cytokine secretion profile to Th2 responses and the promotion of regulatory T cell and(More)
Cyclophosphamide (CY) accelerates autoimmune diabetes in the NOD mouse at different levels, including critical targeting of a regulatory T cell subset, exacerbation of pro-Th1 IFN-gamma production and promotion of inflammation in pancreatic islets. Here we evaluated the ability of G-CSF to antagonize the acceleration of the disease induced by CY. Human(More)
OBJECTIVE Expansion of regulatory T (Treg) cells has been described in chronically HIV-infected individuals. We investigated whether HIV-suppressive Treg could be detected during primary HIV infection (PHI). METHODS Seventeen patients diagnosed early after PHI (median: 13 days; 1-55) were studied. Median CD4 cell count was 480 cells/microl (33-1306) and(More)
Notch proteins play an important role in embryonic development and cell-fate decisions. Notch influences also the activation and differentiation of peripheral T cells. Here, we investigated whether Notch signaling modulates the response of effector T cells to regulatory T (Treg) cells. Pre-exposure of CD4(+) CD25(-) effector T cells to the Notch ligands(More)