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. 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: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 (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.
Project description:XCR1+ dendritic cells (DC) have been shown to excel in antigen cross-presentation for the activation of naïve CD8 T cells. This property was reported to be associated to the subset of the XCR1+ DC expressing IL-12b upon ex vivo stimulation for 24 h with a mixture of CpG, IFN-γ, and GM-CSF (Lin ML et al. Proc Natl Acad Sci USA. 2008. PMID: 18272486). DC found in the steady-state non-lymphoid tissues undergo an homeostatic, tolerogenic, maturation and migrate to the draining lymph nodes to interact with naive autoreactive T cells and induction their peripheral tolerance. In contrast, spleen DC are thought to exist solely in an immature state. The aim of this study was to re-examine heterogeneity within steady state spleen XCR1+ DC, in particular examining whether this population encompass a fraction of mature DCs as assessed through their expression of CCR7 and/or the Il12b gene. Indeed, we show that a small fraction of XCR1+ spleen DC constitutively mature into two distinct but likely successive activation stages characterized as CCR7+ and CCR7+Il12b+ respectively, and correlated with increasing ability to cross-present antigen to naïve CD8 T cells. Transcriptomic analysis of the subsets of XCR1+ DC found in steady state spleen unexpectedly showed that their homeostatic maturation was unexpectedly associated with up-regulated of many genes thought to drive pro-inflammatory T-cell responses and previously found to be commonly induced upon maturation of distinct DC subsets in response to stimulation by various microbial-type stimuli (Vu Manh TP et al. Eur J Immunol. 2013. PMID: 23553052). Thus, our results reveal that spleen XCR1+ DC undergo constitutive maturation and emphasize the common mechanisms operating upon homeostatic, tolerogenic, DC maturation versus microbial-type stimuli-induced, immunogenic, DC maturation. DC were isolated from the spleen of untreated Il12b-EYFP reporter mice (Reinhardt RL et al. J Immunol. 2006. PMID:16849470) mice as previously described (Robbins SH et al. Genome Biol. 2008. PMID: 18218067; Baranek T et al. Cell Host Microbe. 2012. PMID: 23084923). DC subsets were sorted by flow cytometry according to the marker combinations described in the âcharacteristics: phenotypeâ field for each sample.
Project description:XCR1+ dendritic cells (DC) have been shown to excel in antigen cross-presentation for the activation of naïve CD8 T cells. This property was reported to be associated to the subset of the XCR1+ DC expressing IL-12b upon ex vivo stimulation for 24 h with a mixture of CpG, IFN-γ, and GM-CSF (Lin ML et al. Proc Natl Acad Sci USA. 2008. PMID: 18272486). DC found in the steady-state non-lymphoid tissues undergo an homeostatic, tolerogenic, maturation and migrate to the draining lymph nodes to interact with naive autoreactive T cells and induction their peripheral tolerance. In contrast, spleen DC are thought to exist solely in an immature state. The aim of this study was to re-examine heterogeneity within steady state spleen XCR1+ DC, in particular examining whether this population encompass a fraction of mature DCs as assessed through their expression of CCR7 and/or the Il12b gene. Indeed, we show that a small fraction of XCR1+ spleen DC constitutively mature into two distinct but likely successive activation stages characterized as CCR7+ and CCR7+Il12b+ respectively, and correlated with increasing ability to cross-present antigen to naïve CD8 T cells. Transcriptomic analysis of the subsets of XCR1+ DC found in steady state spleen unexpectedly showed that their homeostatic maturation was unexpectedly associated with up-regulated of many genes thought to drive pro-inflammatory T-cell responses and previously found to be commonly induced upon maturation of distinct DC subsets in response to stimulation by various microbial-type stimuli (Vu Manh TP et al. Eur J Immunol. 2013. PMID: 23553052). Thus, our results reveal that spleen XCR1+ DC undergo constitutive maturation and emphasize the common mechanisms operating upon homeostatic, tolerogenic, DC maturation versus microbial-type stimuli-induced, immunogenic, DC maturation.
Project description:Broad and largely overlapping molecular changes arise in thymic and peripheral XCR1+ dendritic cells upon tolerogenic and immunogenic maturation
Project description:Broad and largely overlapping molecular changes arise in thymic and peripheral XCR1+ dendritic cells upon tolerogenic and immunogenic maturation [reanalyzed samples]
Project description:XCR1 is known as a signature receptor of type 1 conventional dendritic cells To compare the transcriptomic differences of WT and XCR1 deficient type 1 conventional dendritic cells, we conducted microarry using type 1 conventional dendritic cells from WT and XCR1 KO mice