Transcription profiling of human bronchial epithelial cells from normal and asthmatic subjects exposed to either ozone or rhinovirus
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ABSTRACT: The exacerbation of disease in asthmatics has been linked to both exposure to environmental agents as well as to the presence of virus in airways, particularly rhinovirus. The hypothesis tested in these experiments is that differences in gene expression profiles in epithelial cells derived from asthmatic and normal airways can be linked to enhanced responsiveness of the epithelium in its pro-inflammatory, immulogic or other activities that may lead to the exacerbation of disease.
Project description:Asthma is a very frequent airway disease that affects 6 to 20% of the population. Severe asthma, represents 3 to 5% of all asthmatic patients and is histologically characterized by an increased bronchial smooth muscle (BSM) mass and clinically by viral exacerbations. Functionally, BSM remodeling had a poor prognostic value in asthma, since higher BSM mass was associated with lower lung function and increased exacerbation rate. However, the role of BSM as a potential actor of asthma exacerbation has only been sparsely suggested. We thus hypothesis that asthmatic BSM cells could act on bronchial epithelium and modified its response to rhinovirus infection.
Project description:Background: Evidence suggests that immune responses to rhinovirus A and C are altered in asthmatic children and rhinovirus species induce different types of antibody responses. Objective: To ascertain and compare the T-cell memory response induced by RV-A and RV-C in asthmatic and non-asthmatic children. Methods: Peripheral blood mononuclear cells from children who previously suffered asthma exacerbation (asthmatics) and non-asthmatic controls were stimulated in vitro with peptide formulations to induce representative species-specific responses to RV-A and RV-C. Expression of genes was measured by RNA-seq and differentially expressed genes were further analysed to identify enriched pathways and upstream regulators. Results: Responses to RV-A showed markedly higher upregulation of IFNG and the IFNG responsive genes CXCL9, 10 and 11 and STAT1 compared to RV-C. There was no reciprocal upregulation of Th2 cytokine genes or the Th2 chemokine genes CCL11, CCL17 and CCL22. RV-C but not RV-A induced high upregulation of CCL24 (eotaxin-2) in both non-asthmatic and asthmatic responses. Upstream regulator analysis showed both RV-A and, although to a diminished extent, RV-C induced predominant Th1 and inflammatory cytokine expression. The responses of asthmatics compared to non-asthmatics was diminished to both RV-A and RV-C while retaining the pattern for gene expression and upstream regulators characteristic of each species and there was no upregulation of Th2-type responses. All groups showed activation of the IL-17A pathway. Conclusions: RV-C induced memory cells with a lower IFNG type response than RV-A without Th2 upregulation. Asthmatics had lower recall responses than non-asthmatics while largely retaining the same gene activation profile for each species.
Project description:The exacerbation of disease in asthmatics has been linked to both exposure to environmental agents as well as to the presence of virus in airways, particularly rhinovirus. The hypothesis tested in these experiments is that differences in gene expression profiles in epithelial cells derived from asthmatic and normal airways can be linked to enhanced responsiveness of the epithelium in its pro-inflammatory, immulogic or other activities that may lead to the exacerbation of disease. Keywords: other
Project description:We report the application of RNA sequencing technology for high-throughput profiling of gene expression responses to human rhinovirus infection at 24 hours in air-liquid interface human airway epithelial cell cultures derived from 6 asthmatic and 6 non-asthmatic donors. RNA-seq analysis identified sets of genes associated with asthma specific viral responses. These genes are related to inflammatory pathways, epithelial remodeling and cilium assembly and function, including those described previously (e.g. CCL5, CXCL10 and CX3CL1), and novel ones that were identified for the first time in this study (e.g. CCRL1, CDHR3). We concluded that air liquid interface cultured human airway epithelial cells challenged with live HRV are a useful in vitro model for the study of rhinovirus induced asthma exacerbation, given that our findings are consistent with clinical data sets. Furthermore, our data suggest that abnormal airway epithelial structure and inflammatory signaling are important contributors to viral induced asthma exacerbation. Differentiated air-liquid interface cultured human airway epithelial cell mRNA profiles from 6 asthmatic and 6 non-asthmatic donors after 24 hour treatment with either HRV or vehicle control were generated by deep sequencing, using Illumina HiSeq 2000.
Project description:We report the application of RNA sequencing technology for high-throughput profiling of gene expression responses to human rhinovirus infection at 24 hours in air-liquid interface human airway epithelial cell cultures derived from 6 asthmatic and 6 non-asthmatic donors. RNA-seq analysis identified sets of genes associated with asthma specific viral responses. These genes are related to inflammatory pathways, epithelial remodeling and cilium assembly and function, including those described previously (e.g. CCL5, CXCL10 and CX3CL1), and novel ones that were identified for the first time in this study (e.g. CCRL1, CDHR3). We concluded that air liquid interface cultured human airway epithelial cells challenged with live HRV are a useful in vitro model for the study of rhinovirus induced asthma exacerbation, given that our findings are consistent with clinical data sets. Furthermore, our data suggest that abnormal airway epithelial structure and inflammatory signaling are important contributors to viral induced asthma exacerbation.
Project description:Background: Mechanisms underlying the development of virus-induced asthma exacerbations remain unclear. Objective: To investigate if epigenetic mechanisms could be involved in virus-induced asthma exacerbations, we undertook DNA methylation profiling in asthmatic and healthy nasal epithelial cells (NECs) during Human Rhinovirus (HRV) infection in vitro. Methods: Global and loci-specific methylation profiles were determined via Alu element and Infinium Human Methylation 450K microarray respectively. Principal components analysis identified the genomic loci influenced the most by disease-status and infection. Real-time PCR and pyrosequencing was used to confirm gene expression and DNA methylation respectively. Results: Global methylation was increased in Asthmatics during infection. Disease status and virus infection influenced the methylation of 389 loci. Healthy and asthmatic NECs were characterized predominately by methylation profiles and patterns in loci that were not influenced by virus infection. However, both groups also exhibited distinct DNA methylation profiles in response to infection. Despite these differences, we found that the methylation of small nucleolar RNA, H/ACA box 12 (SNORA12) was common during infection. Further analysis indicated a relationship existed between SNORA12 DNA methylation and gene expression in response to infection. Conclusions: Findings from our study indicate that in addition to the well described phenotypic and genomic differences, the airway epithelium of asthmatics is characterized by a distinct methylome and that epigenetic mechanism may contribute to the development of virus-induced asthma exacerbations. Bisulphite converted DNA from matched mock and human rhinovirus-16 infected nasal epithelial cells from Healthy (n=3) and Asthmatics (n=6) adults were hybridized to the Illumina DNA methylation 450K Bead Array.
Project description:Asthma is a very frequent airway disease that affects 6 to 20% of the population. Severe asthma, represents 3 to 5% of all asthmatic patients and is histologically characterized by an increased bronchial smooth muscle (BSM) mass and clinically by viral exacerbations. Functionally, BSM remodeling had a poor prognostic value in asthma, since higher BSM mass was associated with lower lung function and increased exacerbation rate. However, the role of BSM as a potential actor of asthma exacerbation has only been sparsely suggested. Thus, we hypothesis that asthmatic BSM cell metabolism is modified compare to that of non-asthmatic and that could be a potential target to reduce asthmatic BSM cell proliferation and remodeling in asthma.
Project description:Background: Mechanisms underlying the development of virus-induced asthma exacerbations remain unclear. Objective: To investigate if epigenetic mechanisms could be involved in virus-induced asthma exacerbations, we undertook DNA methylation profiling in asthmatic and healthy nasal epithelial cells (NECs) during Human Rhinovirus (HRV) infection in vitro. Methods: Global and loci-specific methylation profiles were determined via Alu element and Infinium Human Methylation 450K microarray respectively. Principal components analysis identified the genomic loci influenced the most by disease-status and infection. Real-time PCR and pyrosequencing was used to confirm gene expression and DNA methylation respectively. Results: Global methylation was increased in Asthmatics during infection. Disease status and virus infection influenced the methylation of 389 loci. Healthy and asthmatic NECs were characterized predominately by methylation profiles and patterns in loci that were not influenced by virus infection. However, both groups also exhibited distinct DNA methylation profiles in response to infection. Despite these differences, we found that the methylation of small nucleolar RNA, H/ACA box 12 (SNORA12) was common during infection. Further analysis indicated a relationship existed between SNORA12 DNA methylation and gene expression in response to infection. Conclusions: Findings from our study indicate that in addition to the well described phenotypic and genomic differences, the airway epithelium of asthmatics is characterized by a distinct methylome and that epigenetic mechanism may contribute to the development of virus-induced asthma exacerbations.
Project description:Human Rhinovirus (HRV) infection can trigger exacerbations of asthma. Understanding of the mechanisms provoking airway inflammation and remodeling in asthma, as well as the pathogenic mechanisms of HRV infection and its association with asthma exacerbations, may offer significant opportunities for improved disease management. Genome-wide expression analysis of HRV type 1A-infected primary bronchial epithelial (PBE) cells from normal and asthmatic donors was performed to determine whether asthma is associated with a unique pattern of gene expression after HRV infection in vitro. Experiment Overall Design: Frozen stocks of human PBE cells obtained from the bronchial brushings of six normal and five asthmatic individuals were grown in vitro in Bronchial Epithelial Growth Media (BEGM, Lonza). Subconfluent monolayers of PBE cells were infected with purified and concentrated minor group HRV serotype 1A at multiplicity of infection of 10 plaque forming units (pfu) per cell or mock-infected with growth media alone. Cells were lysed 16 hours post infection (p.i.) and isolated total RNAs were analyzed using the Human Genome U133 Plus 2.0 GeneChip arrays (Affymetrix, Santa Clara, CA).
Project description:Human Rhinovirus (HRV) infection can trigger exacerbations of asthma. Understanding of the mechanisms provoking airway inflammation and remodeling in asthma, as well as the pathogenic mechanisms of HRV infection and its association with asthma exacerbations, may offer significant opportunities for improved disease management. Genome-wide expression analysis of HRV type 1A-infected primary bronchial epithelial (PBE) cells from normal and asthmatic donors was performed to determine whether asthma is associated with a unique pattern of gene expression after HRV infection in vitro. Keywords: response to rhinovirus infection