- Email: [email protected]
ID: 246
110
Abstract / Cytokine 76 (2015) 66–112
promoters, in IFNa-dependent STAT1-independent manner. STAT2/IRF9 was able to generate a sustained antiviral response upon EMCV and VSV. Interestingly, IFNa-treated NB4 cells that display transient phosphorylation of STAT1 and prolonged phosphorylation of STAT2, revealed transient STAT1-mediated ISG expression and prolonged expression of STAT2/IRF9-dependent genes. Our results prove that IFNa-activated STAT2/IRF9 induces prolonged ISGF3-like transcriptome and generates an antiviral response in the absence of STAT1. We provide additional evidence that in the presence of STAT1, abundance and phosphorylation kinetics of ISGF3 components dictates the nature of IFNa responses. http://dx.doi.org/10.1016/j.cyto.2015.08.245
ID: 243 Pro-atherogenic roles of STAT1 and IRF8 in cardiovascular disease Anna Piaszyk-Borychowska 1,*, Joanna Wesoły 2, Hans Bluyssen 1, 1 Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland, 2 Laboratory of High-throughput Technologies, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland * Corresponding author. Signal integration between IFNc and TLRs in immune cells has been associated with the host defense against pathogens and injury, with a predominant role of STAT1. We hypothesized that STAT1-dependent transcriptional changes in vascular cells involved in cross-talk between IFNc and TLR4, reflect pro-atherogenic responses in human atherosclerosis. RNA-seq analysis identified a specific set of STAT1-dependent genes that were synergistically affected by interactions between IFNc and LPS in primary aortic VSMCs. These included multiple chemokines, adhesion molecules, antiviral and antibacterial response genes. Among the amplified genes was also IRF8, of which CCL5 and NOS2 were identified as new pro-inflammatory targets. Promoter analysis, combined with ChIP-PCR predicted transcriptional cooperation between STAT1, IRF1, IRF8 and NFjB driving cross-talk between IFNc and TLR4, with IRF8 providing an additional layer to the overall complexity. The STAT1-dependent synergistic interactions between IFNc and LPS also resulted in increased T-cell migration and impaired aortic contractility. Expression of the chemokines CXCL9 and CXCL10 correlated with STAT1 phosphorylation in vascular cells in plaques from human carotid arteries. Moreover, using data mining of human plaque transcriptomes, expression of a selection of these STAT1-dependent pro-atherogenic genes was found to be increased in coronary artery disease (CAD) and carotid atherosclerosis. We provide evidence to suggest that in ECs and VSMCs STAT1 and IRF8 orchestrate a platform for cross-talk between IFNc and TLR4, and identify a STAT1-dependent gene signature that reflects a proatherogenic state in human atherosclerosis. The novel ‘‘inflammation-dependent” role of IRF8 in cells from the vasculature will be further presented. http://dx.doi.org/10.1016/j.cyto.2015.08.246
ID: 245 The impact of Interleukin-4 on CD4+ T cell metabolism Graham Anthony Heieis *, Stephen Redpath, Nicolette Fonseca, Georgia PeronaWright, University of British Columbia, Canada * Corresponding author. Upon activation, CD4+ T cells adopt a highly glycolytic metabolism to meet the increased energy demands of proliferation and cytokine production. It has been reported that different CD4+ T cell subsets exhibit different metabolic profiles, implying they may have unique metabolic requirements. Studies have shown that Th2 cells have higher glycolytic rates than other effector subsets, but the functional significance of this is unknown. Interleukin (IL)-4 is the orchestrating cytokine of the Th2 response and IL-4 signaling is widespread throughout a Th2 lymph node. Bystander cells present in the lymph node are exposed to IL-4 signals without antigen-specific stimulation, and this ambient cytokine exposure predisposes them towards Th2 differentiation during subsequent activation. We hypothesize that IL-4 signaling dictates CD4+ T cell metabolism and thus determines T cell fate. Our data describe similarities and differences in the metabolic profiles of active and bystander CD4+ T cells, generated during Th1 and Th2 responses in vitro and in vivo. Our findings provide new insight into the ability of cytokines induced by one immune challenge to influence T cell function in a subsequent response. A third of the world’s population is currently infected with Th2-driving helminths, and co-infection is frequent. Targeting the mechanisms of cytokine crosstalk during co-infection promises to yield significant health benefit. http://dx.doi.org/10.1016/j.cyto.2015.08.248
ID: 246 CD4+ T cell derived IL-10 is independent of IL-27 signaling in a recall response to influenza Nicolette Fonseca *, Stephen Alexander Redpath, Kristy Dockstader, Georgia Perona Wright, University of British Columbia, Canada * Corresponding author. Surviving influenza infection requires a careful balance of pro-inflammatory signals that promote viral clearance and anti-inflammatory signals that prevent immunopathology. IL-10 is a potent immunosuppressive cytokine that is essential to this balance. Evidence suggests that in CD4+ T cells, IL-10 expression is critically dependent on IL-27 signalling. Here we show in vitro and in vivo that CD4+ cells downregulate gp130, the signal transduction component of the IL-27 receptor, upon activation. Gp130 expression remains low throughout CD4+ T cell contraction and memory, and renders the T cells non-responsive to IL-27 stimulation. Despite this, during secondary activation, effector CD4+ T cells express IL-10 at a level equivalent to their primary effector counterparts. CD4+ T cells genetically deficient for Il27ra (IL27ra / ) also fail to express IL-10 during primary activation but are equivalent to wildtype cells during a secondary response. Together our data highlight an IL-27 independent mechanism of IL-10 regulation that is unique to secondary CD4+ T cell activation, and plays a decisive role in the balance between effective immunity and immunopathology during influenza-induced respiratory disease.
ID: 244 Eosinophil IL-13 polarizes CD11b+ CD103+ dendritic cells to initiate Th2 immune responses in the gut associated lymphoid tissue
http://dx.doi.org/10.1016/j.cyto.2015.08.249
Stephen Alexander Redpath *, Lisa Reynolds, Graham Heieis, Nicolette Fonseca, Georgia Perona-Wright, University of British Columbia, Canada * Corresponding author.
ID: 247 Anti-inflammatory cytokines as mediators of epithelial repair during influenza infection of the lung
Dendritic cells are key to the initiation and regulation of immune responses. In the gut there are three distinct dendritic cell (DC) subsets, defined by CD11b and CD103, each with different developmental requirements and distinct functional potential. Recent evidence has described a role for the different gut DC subsets in the generation of Th17 and Treg responses, but little is yet known of their contribution to the initiation of Th2 immune responses in the intestines. We used the nematode Heligmosomoides polygyrus to initiate a potent Th2 response in the small intestine. We found that during H. polygyrus infection CD11b+ CD103+ DC preferentially migrated from the site of infection to the local lymph node. These DC showed increased expression of PDL2 and had an enhanced capacity to prime naive CD4+ T cell toward Th2. Migration and activation of CD11b+ CD103+ DC was dependent on the cytokine IL-13, which was secreted by activated eosinophils at the site of infection. Together our data suggest that the initiation of a Th2 response in the intestines involves early activation of eosinophils, which secrete the cytokine needed to activate and mobilize Th2-driving DCs. http://dx.doi.org/10.1016/j.cyto.2015.08.247
Kristy L. Dockstader 1, Nicolette M. Fonseca 1, Tillie L. Hackett 2, Georgia PeronaWright 1, 1 University of British Columbia, Canada , 2 Centre for Heart Lung Innovation, Canada The Influenza A virus causes severe respiratory infections that are a major health problem on a global scale. Annual outbreaks of influenza result in up to 8000 deaths in Canada each year, especially affecting the elderly, the young and others with a compromised immune system. The key to surviving an influenza infection is the generation of a balanced immune response, in which maximum viral clearance occurs with minimum collateral damage. The anti-inflammatory cytokine interleukin-10 (IL-10) is a critical mediator of this balance. We hypothesize that, during an influenza infection, IL-10 not only regulates the immune system but also plays a direct role in the repair and remodelling of lung epithelial tissue. We show that IL-10 is produced throughout an influenza infection, continuing even after the anti-viral immune response ends. IL-10 receptor expression is widespread and includes lung epithelial cells. Experiments to determine the impact of IL-10 on the proliferation and repair of pulmonary epithelial cells are underway. Together our data demonstrate the
Abstract / Cytokine 76 (2015) 66–112
promoters, in IFNa-dependent STAT1-independent manner. STAT2/IRF9 was able to generate a sustained antiviral response upon EMCV and VSV. Interestingly, IFNa-treated NB4 cells that display transient phosphorylation of STAT1 and prolonged phosphorylation of STAT2, revealed transient STAT1-mediated ISG expression and prolonged expression of STAT2/IRF9-dependent genes. Our results prove that IFNa-activated STAT2/IRF9 induces prolonged ISGF3-like transcriptome and generates an antiviral response in the absence of STAT1. We provide additional evidence that in the presence of STAT1, abundance and phosphorylation kinetics of ISGF3 components dictates the nature of IFNa responses. http://dx.doi.org/10.1016/j.cyto.2015.08.245
ID: 243 Pro-atherogenic roles of STAT1 and IRF8 in cardiovascular disease Anna Piaszyk-Borychowska 1,*, Joanna Wesoły 2, Hans Bluyssen 1, 1 Department of Human Molecular Genetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland, 2 Laboratory of High-throughput Technologies, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland * Corresponding author. Signal integration between IFNc and TLRs in immune cells has been associated with the host defense against pathogens and injury, with a predominant role of STAT1. We hypothesized that STAT1-dependent transcriptional changes in vascular cells involved in cross-talk between IFNc and TLR4, reflect pro-atherogenic responses in human atherosclerosis. RNA-seq analysis identified a specific set of STAT1-dependent genes that were synergistically affected by interactions between IFNc and LPS in primary aortic VSMCs. These included multiple chemokines, adhesion molecules, antiviral and antibacterial response genes. Among the amplified genes was also IRF8, of which CCL5 and NOS2 were identified as new pro-inflammatory targets. Promoter analysis, combined with ChIP-PCR predicted transcriptional cooperation between STAT1, IRF1, IRF8 and NFjB driving cross-talk between IFNc and TLR4, with IRF8 providing an additional layer to the overall complexity. The STAT1-dependent synergistic interactions between IFNc and LPS also resulted in increased T-cell migration and impaired aortic contractility. Expression of the chemokines CXCL9 and CXCL10 correlated with STAT1 phosphorylation in vascular cells in plaques from human carotid arteries. Moreover, using data mining of human plaque transcriptomes, expression of a selection of these STAT1-dependent pro-atherogenic genes was found to be increased in coronary artery disease (CAD) and carotid atherosclerosis. We provide evidence to suggest that in ECs and VSMCs STAT1 and IRF8 orchestrate a platform for cross-talk between IFNc and TLR4, and identify a STAT1-dependent gene signature that reflects a proatherogenic state in human atherosclerosis. The novel ‘‘inflammation-dependent” role of IRF8 in cells from the vasculature will be further presented. http://dx.doi.org/10.1016/j.cyto.2015.08.246
ID: 245 The impact of Interleukin-4 on CD4+ T cell metabolism Graham Anthony Heieis *, Stephen Redpath, Nicolette Fonseca, Georgia PeronaWright, University of British Columbia, Canada * Corresponding author. Upon activation, CD4+ T cells adopt a highly glycolytic metabolism to meet the increased energy demands of proliferation and cytokine production. It has been reported that different CD4+ T cell subsets exhibit different metabolic profiles, implying they may have unique metabolic requirements. Studies have shown that Th2 cells have higher glycolytic rates than other effector subsets, but the functional significance of this is unknown. Interleukin (IL)-4 is the orchestrating cytokine of the Th2 response and IL-4 signaling is widespread throughout a Th2 lymph node. Bystander cells present in the lymph node are exposed to IL-4 signals without antigen-specific stimulation, and this ambient cytokine exposure predisposes them towards Th2 differentiation during subsequent activation. We hypothesize that IL-4 signaling dictates CD4+ T cell metabolism and thus determines T cell fate. Our data describe similarities and differences in the metabolic profiles of active and bystander CD4+ T cells, generated during Th1 and Th2 responses in vitro and in vivo. Our findings provide new insight into the ability of cytokines induced by one immune challenge to influence T cell function in a subsequent response. A third of the world’s population is currently infected with Th2-driving helminths, and co-infection is frequent. Targeting the mechanisms of cytokine crosstalk during co-infection promises to yield significant health benefit. http://dx.doi.org/10.1016/j.cyto.2015.08.248
ID: 246 CD4+ T cell derived IL-10 is independent of IL-27 signaling in a recall response to influenza Nicolette Fonseca *, Stephen Alexander Redpath, Kristy Dockstader, Georgia Perona Wright, University of British Columbia, Canada * Corresponding author. Surviving influenza infection requires a careful balance of pro-inflammatory signals that promote viral clearance and anti-inflammatory signals that prevent immunopathology. IL-10 is a potent immunosuppressive cytokine that is essential to this balance. Evidence suggests that in CD4+ T cells, IL-10 expression is critically dependent on IL-27 signalling. Here we show in vitro and in vivo that CD4+ cells downregulate gp130, the signal transduction component of the IL-27 receptor, upon activation. Gp130 expression remains low throughout CD4+ T cell contraction and memory, and renders the T cells non-responsive to IL-27 stimulation. Despite this, during secondary activation, effector CD4+ T cells express IL-10 at a level equivalent to their primary effector counterparts. CD4+ T cells genetically deficient for Il27ra (IL27ra / ) also fail to express IL-10 during primary activation but are equivalent to wildtype cells during a secondary response. Together our data highlight an IL-27 independent mechanism of IL-10 regulation that is unique to secondary CD4+ T cell activation, and plays a decisive role in the balance between effective immunity and immunopathology during influenza-induced respiratory disease.
ID: 244 Eosinophil IL-13 polarizes CD11b+ CD103+ dendritic cells to initiate Th2 immune responses in the gut associated lymphoid tissue
http://dx.doi.org/10.1016/j.cyto.2015.08.249
Stephen Alexander Redpath *, Lisa Reynolds, Graham Heieis, Nicolette Fonseca, Georgia Perona-Wright, University of British Columbia, Canada * Corresponding author.
ID: 247 Anti-inflammatory cytokines as mediators of epithelial repair during influenza infection of the lung
Dendritic cells are key to the initiation and regulation of immune responses. In the gut there are three distinct dendritic cell (DC) subsets, defined by CD11b and CD103, each with different developmental requirements and distinct functional potential. Recent evidence has described a role for the different gut DC subsets in the generation of Th17 and Treg responses, but little is yet known of their contribution to the initiation of Th2 immune responses in the intestines. We used the nematode Heligmosomoides polygyrus to initiate a potent Th2 response in the small intestine. We found that during H. polygyrus infection CD11b+ CD103+ DC preferentially migrated from the site of infection to the local lymph node. These DC showed increased expression of PDL2 and had an enhanced capacity to prime naive CD4+ T cell toward Th2. Migration and activation of CD11b+ CD103+ DC was dependent on the cytokine IL-13, which was secreted by activated eosinophils at the site of infection. Together our data suggest that the initiation of a Th2 response in the intestines involves early activation of eosinophils, which secrete the cytokine needed to activate and mobilize Th2-driving DCs. http://dx.doi.org/10.1016/j.cyto.2015.08.247
Kristy L. Dockstader 1, Nicolette M. Fonseca 1, Tillie L. Hackett 2, Georgia PeronaWright 1, 1 University of British Columbia, Canada , 2 Centre for Heart Lung Innovation, Canada The Influenza A virus causes severe respiratory infections that are a major health problem on a global scale. Annual outbreaks of influenza result in up to 8000 deaths in Canada each year, especially affecting the elderly, the young and others with a compromised immune system. The key to surviving an influenza infection is the generation of a balanced immune response, in which maximum viral clearance occurs with minimum collateral damage. The anti-inflammatory cytokine interleukin-10 (IL-10) is a critical mediator of this balance. We hypothesize that, during an influenza infection, IL-10 not only regulates the immune system but also plays a direct role in the repair and remodelling of lung epithelial tissue. We show that IL-10 is produced throughout an influenza infection, continuing even after the anti-viral immune response ends. IL-10 receptor expression is widespread and includes lung epithelial cells. Experiments to determine the impact of IL-10 on the proliferation and repair of pulmonary epithelial cells are underway. Together our data demonstrate the