Project description:Th1 is the predominant phenotype during the early stage of MI. XCR1+ cDC1 activated CXCR3+ Th1 could be a novel therapeutic target for ischemic cardiac remodeling.
Project description:Th1 is the predominant phenotype during the early stage of MI. XCR1+ cDC1 activated CXCR3+ Th1 could be a novel therapeutic target for ischemic cardiac remodeling.
Project description:Dendritic cells (DC) play critical roles in central and peripheral T cell tolerance. DC found in the steady-state periphery undergo an homeostatic, tolerogenic, maturation that promotes interaction with naive T cells and induction of abortive responses. In contrast, thymic DC are thought to exist solely in an immature state. In this study, we show that XCR1+ thymic DC constitutively mature into a stage characterized by high levels of molecules involved in T cell activation. This unanticipated mature stage corresponded to a third of the XCR1+ thymic DC and fully accounted for their ability to cross-present self-antigens to developing T cells. Transcriptomic analysis of the XCR1+ DC found in thymus and steady-state periphery revealed that their maturation involves profound and convergent changes. Unexpectedly, maturation resulted in down-regulation of genes conferring their specific function on XCR1+ DC. Paradoxically, upon maturation, central and peripheral tolerogenic XCR1+ DC up-regulated many genes thought to drive pro-inflammatory T-cell responses. Thus, our results reveal that thymic XCR1+ DC undergo constitutive maturation and emphasize the common mechanisms operating for both central and peripheral tolerance induction by XCR1+ DC. DC were isolated from lymphoid organs as previously described (Vremec et al., 2000). DC subsets were sorted by flow cytometry according to the marker combinations described in the âcharacteristics: phenotypeâ field for each sample.
Project description:Dendritic cells (DC) play critical roles in central and peripheral T cell tolerance. DC found in the steady-state periphery undergo an homeostatic, tolerogenic, maturation that promotes interaction with naive T cells and induction of abortive responses. In contrast, thymic DC are thought to exist solely in an immature state. In this study, we show that XCR1+ thymic DC constitutively mature into a stage characterized by high levels of molecules involved in T cell activation. This unanticipated mature stage corresponded to a third of the XCR1+ thymic DC and fully accounted for their ability to cross-present self-antigens to developing T cells. Transcriptomic analysis of the XCR1+ DC found in thymus and steady-state periphery revealed that their maturation involves profound and convergent changes. Unexpectedly, maturation resulted in down-regulation of genes conferring their specific function on XCR1+ DC. Paradoxically, upon maturation, central and peripheral tolerogenic XCR1+ DC up-regulated many genes thought to drive pro-inflammatory T-cell responses. Thus, our results reveal that thymic XCR1+ DC undergo constitutive maturation and emphasize the common mechanisms operating for both central and peripheral tolerance induction by XCR1+ DC.
Project description:Dendritic cells (DCs) are major regulators of innate and adaptive immune responses. DCs can be classified into plasmacytoid DCs and conventional DCs (cDCs) type 1 and 2. Murine and human cDC1 share the mRNA expression of XCR1. Murine studies indicated a specific role of the XCR1-XCL1 axis in the induction of immune responses. Here, we describe that human cDC1 can be distinguished into XCR1- and XCR1+ cDC1 in lymphoid as well as non-lymphoid tissues. Steady state XCR1+ cDC1 display a pre-activated phenotype compared to XCR1- cDC1. Upon stimulation, XCR1+ cDC1, but not XCR1- cDC1, secreted high levels of inflammatory cytokines as well as chemokines. This was associated with enhanced activation of NK cells mediated by XCR1+ cDC1. Moreover, XCR1+ cDC1 excelled in inhibiting replication of Influenza A virus. Further, under DC differentiation conditions, XCR1- cDC1 developed into XCR1+ cDC1. After acquisition of XCR1 expression, XCR1- cDC1 secreted comparable level of inflammatory cytokines. Thus, XCR1 is a marker of terminally differentiated cDC1 that licenses the antiviral effector functions of human cDC1, while XCR1- cDC1 seem to represent a late immediate precursor of cDC1.
Project description:Dendritic cells (DC) play critical roles in central and peripheral T cell tolerance. DC found in the steady-state periphery undergo an homeostatic, tolerogenic, maturation that promotes interaction with naive T cells and induction of abortive responses. In contrast, thymic DC are thought to exist solely in an immature state. In this study, we show that XCR1+ thymic DC constitutively mature into a stage characterized by high levels of molecules involved in T cell activation. This unanticipated mature stage corresponded to a third of the XCR1+ thymic DC and fully accounted for their ability to cross-present self-antigens to developing T cells. Transcriptomic analysis of the XCR1+ DC found in thymus and steady-state periphery revealed that their maturation involves profound and convergent changes. Unexpectedly, maturation resulted in down-regulation of genes conferring their specific function on XCR1+ DC. Paradoxically, upon maturation, central and peripheral tolerogenic XCR1+ DC up-regulated many genes thought to drive pro-inflammatory T-cell responses. These events occur independtly of type I interferons and of the microlofora, since the same maturation pattern is observed in XCR1+ tDcs from control, Ifnar1-KO and germ-free mice. Thus, our results reveal that thymic XCR1+ DC undergo constitutive maturation and emphasize the common mechanisms operating for both central and peripheral tolerance induction by XCR1+ DC. DC were isolated from thymus organ as previously described (Luche et al., Eur J Immunol. 2011;41:2165-75.PMID: 21630253), from B6 SPF control, B6 germ-free and Ifnar1-KO mice. DC subsets were sorted by flow cytometry according to the marker combinations described in the Sample records' phenotype field.
Project description:We sought to compare the overall transcriptomic differences between TLR stimulated WT and XCR1-deficient type 1 conventional DCs. In addition, we also wanted to investigate functional role of XCR1 signaling in WT type 1 conventional DCs by treating recombinant murine XCL1, a ligand of XCR1 to these cells as well
Project description:To further unravel the potential molecular mechanisms involved in the loss of muscle function during an acute exacerbation, a cross-sectional microarray study was designed to compare the gene expression profile of the vastus lateralis muscle in patients with an acute COPD exacerbation and in stable COPD patients. Keywords: cross-sectional patient study A cross-sectional microarray study was designed. The microarray screening was performed on a vastus lateralis biopsy obtained from 4 patients with an acute COPD exacerbation and 5 stable COPD patients. No replicates or dye-swaps were included.