Project description:Background: A subset of infants are hyper-susceptible to severe/acute viral bronchiolitis (AVB), for reasons unknown. Purpose: To characterise the cellular/molecular mechanisms underlying infant AVB in circulating cells/local airways tissues. Methods: PBMC and nasal mucosal scrapings (NMS) were obtained from Infants (<18mths) and children (1.5-5yrs) during AVB and post-convalescence. Immune response patterns were profiled by multiplex analysis of plasma cytokines, flow cytometry, and transcriptomics (RNA-Seq). Molecular profiling of group-level data utilised a combination of upstream regulator and coexpression network analysis, followed by individual subject-level data analysis employing personalised N-of-1-pathways methodology. Results: Group-level analyses demonstrated that infant PBMC responses were dominated by monocyte-associated hyper-upregulated type I interferon signalling/pro-inflammatory pathways (drivers: TNF, IL6, TREM1, IL1B), versus a combination of inflammation (PTGER2, IL6) plus growth/repair/remodelling pathways (ERBB2, TGFB1, AREG, HGF) coupled with Th2 and NK-cell signalling in children. Age-related differences were not attributable to differential steroid usage or variations in underlying viral pathogens. Nasal mucosal responses were comparable qualitatively in infants/children, dominated by interferon types I-III, but the magnitude of upregulation was higher in infants (range 6-48-fold) than children (5-17-fold). N-of-1-pathways analysis confirmed differential upregulation of innate immunity in infants and NK cell networks in children, and additionally demonstrated covert AVB response sub-phenotypes that were independent of chronological age. Conclusions: Dysregulated expression of interferon-dependent pathways following respiratory viral infections is a defining immunophenotypic feature of AVB-susceptible infants and a subset of children. Susceptible subjects appear to represent a discrete subgroup who cluster based on (slow) kinetics of postnatal maturation of innate immune competence.
Project description:Background: A subset of infants are hyper-susceptible to severe/acute viral bronchiolitis (AVB), for reasons unknown. Purpose: To characterise the cellular/molecular mechanisms underlying infant AVB in circulating cells/local airways tissues. Methods: PBMC and nasal mucosal scrapings (NMS) were obtained from Infants (<18mths) and children (1.5-5yrs) during AVB and post-convalescence. Immune response patterns were profiled by multiplex analysis of plasma cytokines, flow cytometry, and transcriptomics (RNA-Seq). Molecular profiling of group-level data utilised a combination of upstream regulator and coexpression network analysis, followed by individual subject-level data analysis employing personalised N-of-1-pathways methodology. Results: Group-level analyses demonstrated that infant PBMC responses were dominated by monocyte-associated hyper-upregulated type I interferon signalling/pro-inflammatory pathways (drivers: TNF, IL6, TREM1, IL1B), versus a combination of inflammation (PTGER2, IL6) plus growth/repair/remodelling pathways (ERBB2, TGFB1, AREG, HGF) coupled with Th2 and NK-cell signalling in children. Age-related differences were not attributable to differential steroid usage or variations in underlying viral pathogens. Nasal mucosal responses were comparable qualitatively in infants/children, dominated by interferon types I-III, but the magnitude of upregulation was higher in infants (range 6-48-fold) than children (5-17-fold). N-of-1-pathways analysis confirmed differential upregulation of innate immunity in infants and NK cell networks in children, and additionally demonstrated covert AVB response sub-phenotypes that were independent of chronological age. Conclusions: Dysregulated expression of interferon-dependent pathways following respiratory viral infections is a defining immunophenotypic feature of AVB-susceptible infants and a subset of children. Susceptible subjects appear to represent a discrete subgroup who cluster based on (slow) kinetics of postnatal maturation of innate immune competence.
Project description:Human respiratory syncytial virus (HRSV) is the main cause of bronchiolitis during the first year of life, but other viruses such as rhinovirus also occur and are clinically indistinguishable. In hospitalized infants with bronchiolitis, the analysis of the peripheral blood mononuclear cells (PBMC) gene expression might be useful for identification the etiologies caused by HRSV and human rhinovirus (HRV) and to the development of future tests, as well as to elucidate the pathogenic mechanisms triggered by different viral agents and new therapeutic possibilities. In this study, we conducted a comparative global gene expression analysis of infants with acute viral bronchiolitis infected by HRSV (HRSV group) or HRV (HRV group).
Project description:Severe asthma exacerbations in children requiring hospitalisation are typically associated with viral infection, and occur almost exclusively amongst atopics, but the significance of these comorbidities is unknown. We hypothesised that underlying interactions between immunoinflammatory pathways related to responses to aeroallergen and virus are involved, and that evidence of these interactions is detectable in circulating cells during exacerbations. To address this hypothesis we used a genomics-based approach involving profiling of PBMC subpopulations collected during acute exacerbation versus convalescence by microarray and flow cytometry.
Project description:This SuperSeries is composed of the following subset Series: GSE10512: Gene Expression Profiles of PBMC Subsets in Acute GVHD Following Cord Blood Transplantation (IMS v.1) GSE10513: Gene Expression Profiles of PBMC Subsets in Acute GVHD Following Cord Blood Transplantation (IMS v.2) Keywords: SuperSeries Refer to individual Series
Project description:Generalized pustular psoriasis (GPP) is a severe disease featured by neutrophilic pustules and enhanced IL-36 inflammatory pathway in skin. Recently, a transcriptomic analysis of PBMCs and neutrophils in MPO-deficient GPP patients has been performed in stable disease state. However, transcriptomic profiling of PBMCs during acute flare of GPP is unclear. Here, we reported a predominant neutrophil signature in GPP PBMC and a marked increase in the CD66+CD16+ low-density neutrophils (LDNs) within the PBMC fraction of acute GPP patients. Transcriptomic and functional analysis of LDNs revealed a hypoinflammatory phenotype yet enhanced release of neutrophil granule proteases, implicating that LDNs might contribute to the IL-36-mediated inflammation in GPP patients.
Project description:Regulatory T (Treg) cells act as terminators in the case of T cell immunity during the acute phase of viral infection. However, their roles in chronic viral infection are not completely understood. We compared the phenotype and function of Treg cells during acute and chronic viral infection using lymphocytic choriomeningitis virus-infected mouse models. Chronic infection, unlike acute infection, led to induction of Treg cells and upregulation of various inhibitory receptors. Treg cells isolated from chronically infected mice (chronic Treg cells) displayed greater suppressive capacity for inhibiting T cell proliferation and subsequent cytokine production than those from naM-CM-/ve (naive Treg cells) or acutely infected mice (acute Treg cells). These gene expression profiles provided evidence that chronic Treg cells display characteristics distinct from either naive or acute Treg cells. Mouse splenic CD4+CD25+ regulatory T cells were analyzed at 0 day and 16 day after acute or chronic viral infection with LCMV Arm or CL13, respectively.