IgE reactivity profiling in an asthma affected cohort
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ABSTRACT:
ORGANISM(S): Homo sapiens Dermatophagoides pteronyssinus
PROVIDER: GSE20020 | GEO | 2012/01/03
SECONDARY ACCESSION(S): PRJNA124097
REPOSITORIES: GEO
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Project description:Background: Most asthmatic patients have high serum levels of IgE directed against common environmental allergens such as house dust mite, animal danders and moulds. However the presence of specific IgE against individual allergens alone does not account for asthma. Many individuals are atopic but not asthmatic. Precise knowledge of the serum IgE specificity repertoire in asthmatic and non-asthmatic patients would substantially help in understanding the pathogenesis of the disease and at the same time facilitate the treatment and the implementation of preventive measures. Methods: We developed a microarray immunoassay containing 103 common allergens to study the IgE reactivity profiles of 485 asthmatic and 342 non-asthmatic individuals from families whose members had a documented history of asthma and atopy. The results were analyzed using k-means clustering to investigate whether IgE reactivity profiles correlated with asthma, disease severity and age of onset as well as with other atopic conditions such as rhinitis, conjunctivitis and eczema. We trained an artificial neural network (ANN) using the serum reactivity data to identify individuals as asthmatic and non-asthmatic. Results: Individual sera showed clear differences in the number and the combinations of allergens recognized as well as in the level of specific IgE. While the presence of specific IgE against single allergens correlated poorly with the pathological conditions examined k-means clustering analysis unraveled that a particular profile was significantly associated with asthma (p <1E-8). An ANN-based algorithm, calibrated with the profile reactivity data correctly classified as asthmatic or non-asthmatic 78% of the individual examined. Conclusions: Our analysis demonstrates that asthma may be a higher-order phenomenon related to patterns of response and not attributable to single antibody reactions. This information sheds new light on the risk of developing the disease and can be readily utilized in combination with an ANN-based tool to distinguish asthmatic and non-asthmatic individuals on the basis of their serum reactivity profile. The study consisted of a total of 872 sera samples: 485 individuals were diagnosed with asthma, 342 were classified as non asthmatic, a remaining 45 were classified as unconfirmed asthma diagnosis. The serum IgE reactivity profiles were analyzed against 103 allergens representative of 11 distinct allergen classes. Quantification of bound IgE: The fluorescence signal was acquired using ProScanArray Express™ version 3.0 software. PMC reading values of individual spots were corrected against the internal negative control to identify signals above background. Duplicate measurements of individual allergens were utilized. The signal collected from the allergens was interpolated with an external calibration curve to obtain the IU/ml value (see supplementary file GSE20020_IU_ml values.txt), and translated into a Class Score by plotting the data in a standard reactivity scale (see Sample data tables). Class Score values: (CLASS 0 (less than 0.35 IU/ml); CLASS 1 (0.35-0.7 IU/ml); CLASS 2 (0.71-3.5 IU/ml); CLASS 3 (3.51-17.5 IU/ml); CLASS 4 (17.51-50 IU/ml); CLASS 5 (50.01-100 IU/ml).
2012-01-03 | E-GEOD-20020 | biostudies-arrayexpress
Project description:Background: Epigenetic marks, like asthma, are heritable. They are influenced by the environment, direct the maturation of T cellslymphocytes, and have been shown to enhance the development of allergic airways disease in mice. Thus, we hypothesized that epigenetic marks are associated with allergic asthma in inner-city children. Methods: We compared methylation patterns and gene expression in inner-city children with persistent atopic asthma versus healthy controls, using DNA and RNA from peripheral blood mononuclear cells (PBMCs) from inner city children aged 6-12 years with persistent atopic asthma children and healthy controls. Results were externally validated with the GABRIELA study population. Results: Comparing asthmatics (N=97) to controls (N=97), we identified 81 regions that were differentially methylated. Several immune genes were hypomethylated in asthmatics, including IL-13, RUNX3, and a number of specific genes relevant to natural killer cells (KIR2DL4, KIR2DL3, KIR3DL1, and KLRD1) and T cells lymphocytes (TIGIT). 14 differentially methylated regions (DMRs) were associated with the serum IgE concentration of IgE, including RUNX3. These results were internally and externally validated with a global methylation assessment using a different methodology in our inner-city cohort and an independent European cohort (GABRIELA). Hypo- and hypermethylated genes tended to be associated with increased and decreased gene expression, respectively (P<0.6x10-11 for asthma and ; P<0.01 for IgE). To further explore the relationship between methylation and gene expression, we created a matrix of genomic changes in methylation versus transcriptional changes (methyl eQTL) for asthma, and identified cis- and trans-regulated genes whose expression was related to asthma asthma-associated methylation marks. peripheral blood mononuclear cells (PBMCs) from 97 atopic asthmatic and 97 nonatopic nonasthmatic children
2015-02-02 | E-GEOD-40732 | biostudies-arrayexpress
Project description:Background: Epigenetic marks, like asthma, are heritable. They are influenced by the environment, direct the maturation of T cellslymphocytes, and have been shown to enhance the development of allergic airways disease in mice. Thus, we hypothesized that epigenetic marks are associated with allergic asthma in inner-city children. Methods: We compared methylation patterns and gene expression in inner-city children with persistent atopic asthma versus healthy controls, using DNA and RNA from peripheral blood mononuclear cells (PBMCs) from inner city children aged 6-12 years with persistent atopic asthma children and healthy controls. Results were externally validated with the GABRIELA study population. Results: Comparing asthmatics (N=97) to controls (N=97), we identified 81 regions that were differentially methylated. Several immune genes were hypomethylated in asthmatics, including IL-13, RUNX3, and a number of specific genes relevant to natural killer cells (KIR2DL4, KIR2DL3, KIR3DL1, and KLRD1) and T cells lymphocytes (TIGIT). 14 differentially methylated regions (DMRs) were associated with the serum IgE concentration of IgE, including RUNX3. These results were internally and externally validated with a global methylation assessment using a different methodology in our inner-city cohort and an independent European cohort (GABRIELA). Hypo- and hypermethylated genes tended to be associated with increased and decreased gene expression, respectively (P<0.6x10-11 for asthma and ; P<0.01 for IgE). To further explore the relationship between methylation and gene expression, we created a matrix of genomic changes in methylation versus transcriptional changes (methyl eQTL) for asthma, and identified cis- and trans-regulated genes whose expression was related to asthma asthma-associated methylation marks. peripheral blood mononuclear cells (PBMCs) from 97 atopic asthmatic and 97 nonatopic nonasthmatic children
2015-02-02 | E-GEOD-40576 | biostudies-arrayexpress
Project description:Background: Respiratory allergy triggered by pollen allergens is increasing at an alarming rate worldwide. Sunflower pollen is thought to be an important source of inhalant allergens. Present study aims to identify the prevalence of sunflower pollinosis among the Indian allergic population and characterizes the pollen allergens using immuno-proteomic tools. Methodology: Clinico-immunological tests were performed to understand the prevalence of sensitivity towards sunflower pollen among the atopic population. Sera from selected sunflower positive patients were used as probe to detect the IgE-reactive proteins from the one and two dimensionally separated proteome of sunflower pollen. The antigenic nature of the sugar moiety of the glycoprotein allergens was studied by meta-periodate modification of IgE-immunoblot. Finally, these allergens were identified by mass-spectrometry (MALDI TOF/TOF and LC ESI qTOF). MASCOT searching was performed against NCBInr database. However, Helianthus annuus genome is not fully sequenced and partially annotated. So in case of low confidence (p> 0.05) protein identification, searching was performed against EST library of Helianthus annuus. Results: Prevalence of sunflower pollen allergy was observed among 21% of the atopic population and associated with elevated level of specific IgE and histamine in the sera of these patients. Immunoscreening of sunflower pollen proteome with patient serum detected seven IgE-reactive proteins with varying molecular weight and pI. Hierarchical clustering of 2D-immunoblot data highlighted three allergens characterized by a more frequent immuno-reactivity and increased levels of IgE antibodies in the sera of susceptible patients. These allergens were considered as the major allergens of sunflower pollen and were found to have their glycan moiety critical for inducing IgE response. Homology driven search of MS/MS data of these IgE-reactive proteins identified seven previously unreported allergens from sunflower pollen. Three major allergenic proteins were identified as two non-isoformic pectate lyases and a cystein protease. Conclusion: Novelty of the present report is the identification of a panel of seven sunflower pollen allergens for the first time at immuno-biochemical and proteomic level, which substantiated the clinical evidence of sunflower allergy. Further purification and recombinant expression of these allergens will improve component-resolved diagnosis and therapy of pollen allergy.
2015-10-05 | PXD002397 | Pride
Project description:Obesity-associated asthma is recognized as a distinct entity with non-atopic T-helper 1 polarized systemic inflammation. DNA methylation is linked with T helper cell maturation and is associated with inflammatory patterns in asthma and obesity. However, it is unknown whether pathologic dysregulation of DNA methylation patterns occurs in obesity-associated asthma. Using HELP-tagging, we studied epigenome wide DNA methylation in peripheral blood mononuclear cells in 8 urban minority obese asthmatic pre-adolescent children and compared it to methylation in groups of 8 children with asthma alone, obesity alone and healthy controls. Ingenuity Pathway Analysis was used to identify biological pathways that were differentially targeted by methylation dysregulation. We found that obese asthmatics had distinct epigenome wide methylation patterns associated with decreased promoter methylation of a subset of genes, including RANTES, IL-12R and TBX21 and increased promoter methylation of CD23, a low affinity receptor for IgE and of TGFM-NM-2, inhibitor of Th cell activation. T cell signaling and macrophage activation were the two primary pathways that were selectively hypomethylated in obese asthmatics. These methylation patterns suggest that methylation is associated with non-atopic inflammation observed in obese asthmatic children compared to children with asthma alone and obesity alone. Our findings suggest a role of DNA methylation in the observed inflammatory patterns in pediatric obesity-associated asthma in minorities. 32 HpaII test
2014-04-14 | E-GEOD-43705 | biostudies-arrayexpress
Project description:Rationale: Damage to airway epithelium is followed by deposition of extracellular matrix (ECM) and migration of adjacent epithelial cells. We have shown that epithelial cells from asthmatic children fail to heal a wound in vitro. Objectives: To determine whether dysregulated ECM production by the epithelium plays a role in aberrant repair in asthma. Methods: Airway epithelial cells (AEC) from children with asthma (n=36), healthy atopic (n=23) and healthy non-atopic controls (n=53) were investigated by microarray, gene expression and silencing, transcript regulation analysis and ability to close mechanical wounds. Results: Wound repair of AEC from healthy and atopic children were not significantly different and were both faster than AEC from asthmatics. Microarray analysis revealed differential expression of multiple gene sets associated with repair and remodeling in asthmatic AEC. Fibronectin (FN) was the only ECM component whose expression was significantly lower in asthmatic AEC. Expression differences were verified by qPCR and ELISA, and reduced FN expression persisted in asthmatic cells over passage. Silencing of FN expression in non-asthmatic AEC inhibited wound repair, while addition of FN to asthmatic AEC restored reparative capacity. Asthmatic AEC failed to synthesize FN in response to wounding or cytokine/growth factor stimulation. Exposure to 5â, 2âdeoxyazacytidine had no effect on FN expression and subsequent analysis of the FN promoter did not show evidence of DNA methylation. Conclusions: These data show that the reduced capacity of asthmatic epithelial cells to secrete FN is an important contributor to the dysregulated AEC repair observed in these cells. 16 arrays, 2 experimental groups, asthma atopic, AA, and healthy non-atopic, HN.
2010-04-12 | E-GEOD-18965 | biostudies-arrayexpress
Project description:Current diagnostics for allergies, such as skin prick and radioallergosorbent tests, do not allow for inexpensive, high-throughput screening of patients. Additionally, extracts used in these methods are made from washed pollen that lacks pollen surface materials that may contain allergens. We sought to develop a high-throughput assay to rapidly measure allergen-specific IgE levels in sera and to explore the relative allergenicity of different pollen fractions (i.e. surface, cytoplasmic, commercial extracts). To do this, we generated a protein microarray containing surface, cytoplasmic, and commercial extracts from 22 pollen species, commercial extracts from nine non-pollen allergens, and five recombinant allergenic proteins. Arrays were incubated with <25uL of serum from 176 individuals and bound IgE was detected by indirect immunofluorescence, providing a high-throughput measurement of IgE levels.
2010-09-08 | E-MTAB-177 | biostudies-arrayexpress
Project description:Obesity-associated asthma is recognized as a distinct entity with non-atopic T-helper 1 polarized systemic inflammation. DNA methylation is linked with T helper cell maturation and is associated with inflammatory patterns in asthma and obesity. However, it is unknown whether pathologic dysregulation of DNA methylation patterns occurs in obesity-associated asthma. Using HELP-tagging, we studied epigenome wide DNA methylation in peripheral blood mononuclear cells in 8 urban minority obese asthmatic pre-adolescent children and compared it to methylation in groups of 8 children with asthma alone, obesity alone and healthy controls. Ingenuity Pathway Analysis was used to identify biological pathways that were differentially targeted by methylation dysregulation. We found that obese asthmatics had distinct epigenome wide methylation patterns associated with decreased promoter methylation of a subset of genes, including RANTES, IL-12R and TBX21 and increased promoter methylation of CD23, a low affinity receptor for IgE and of TGFβ, inhibitor of Th cell activation. T cell signaling and macrophage activation were the two primary pathways that were selectively hypomethylated in obese asthmatics. These methylation patterns suggest that methylation is associated with non-atopic inflammation observed in obese asthmatic children compared to children with asthma alone and obesity alone. Our findings suggest a role of DNA methylation in the observed inflammatory patterns in pediatric obesity-associated asthma in minorities.
2014-04-14 | GSE43705 | GEO
Project description:Rationale: Asthma and atopy shares common features including Th2-inflammation. However, impairment of airway function seems to be absent in atopy. Increased understanding of the complex cellular and molecular pathways defining the similarities and differences between asthma and atopy may be achieved by transcriptomic analysis (RNA-Seq). Hypothesis and Aims: As the airway smooth muscle (ASM) layer plays an important role in airway function, we hypothesized that the transcriptomic profile of the ASM layer in endobronchial biopsies is different between atopic asthma patients and atopic healthy controls. First, we examined the differences in transcriptomic profiles of the ASM layer in endobronchial biopsies between atopic mild, steroid-free asthma patients, and atopic and non-atopic healthy controls. Second, we investigated the association between the transcriptomic profiles of the ASM layer and airway function. Methods: This cross-sectional study included 12 steroid-free atopic asthma patients, 6 atopic, and 6 non-atopic healthy controls. RNA of ASM from 4 endobronchial biopsies per subject was isolated and sequenced (GS FLX+, 454/Roche). Ingenuity Pathway Analysis was used to identify gene networks. Comparison of the numbers of reads per gene in asthma and controls was based on the negative binomial distribution. At the current sample size the estimated false discovery rate was approximately 1%. Results: Yield of isolated RNA was 30-821ng. We identified 174 differentially expressed genes between asthma and atopic controls, 108 between asthma and non-atopic controls, and 135 between atopic and non-atopic controls. A set of 8 genes was identified, which seems to define asthma patients from non-asthmatic controls regardless of atopy. Four of these genes were significantly associated with airway hyperresponsiveness. Conclusion: A difference in transcriptomic profile of the airway smooth muscle layer in asthma patients compared to atopic and non-atopic healthy controls may lead to a different regulation of inflammatory pathways and of airway smooth muscle function and development resulting in impaired airway function.
2014-08-15 | GSE38003 | GEO
Project description:Rationale: Asthma and atopy shares common features including Th2-inflammation. However, impairment of airway function seems to be absent in atopy. Increased understanding of the complex cellular and molecular pathways defining the similarities and differences between asthma and atopy may be achieved by transcriptomic analysis (RNA-Seq). Hypothesis and Aims: As the airway smooth muscle (ASM) layer plays an important role in airway function, we hypothesized that the transcriptomic profile of the ASM layer in endobronchial biopsies is different between atopic asthma patients and atopic healthy controls. First, we examined the differences in transcriptomic profiles of the ASM layer in endobronchial biopsies between atopic mild, steroid-free asthma patients, and atopic and non-atopic healthy controls. Second, we investigated the association between the transcriptomic profiles of the ASM layer and airway function. Methods: This cross-sectional study included 12 steroid-free atopic asthma patients, 6 atopic, and 6 non-atopic healthy controls. RNA of ASM from 4 endobronchial biopsies per subject was isolated and sequenced (GS FLX+, 454/Roche). Ingenuity Pathway Analysis was used to identify gene networks. Comparison of the numbers of reads per gene in asthma and controls was based on the negative binomial distribution. At the current sample size the estimated false discovery rate was approximately 1%. Results: Yield of isolated RNA was 30-821ng. We identified 174 differentially expressed genes between asthma and atopic controls, 108 between asthma and non-atopic controls, and 135 between atopic and non-atopic controls. A set of 8 genes was identified, which seems to define asthma patients from non-asthmatic controls regardless of atopy. Four of these genes were significantly associated with airway hyperresponsiveness. Conclusion: A difference in transcriptomic profile of the airway smooth muscle layer in asthma patients compared to atopic and non-atopic healthy controls may lead to a different regulation of inflammatory pathways and of airway smooth muscle function and development resulting in impaired airway function. This cross-sectional transcriptomics study consisted of 2 visits. At visit 1, asthma patients (n=12), and healthy atopic (n=6) and non-atopic (n=6) controls were screened for eligibility to participate according to the in- and exclusion criteria. Spirometry and a methacholine bronchoprovocation test were performed. At visit 2, FEV1 reversibility was measured and 4 endobronchial biopsies per subject were collected during a bronchoscopy. Airway smooth muscle was collected from the biopsies by laser capture microdissection and total RNA isolated. cDNA was prepared using the Ovation RNA-Seq System (NuGEN). RNA-Seq was performed using the GS FLX+ instrument (454/Roche). Sequence reads were mapped against the human genome (hg19; UCSC). Comparison of the numbers of reads per gene between asthma and healthy controls was based on the negative binomial distribution and carried out with the R package DESeq including correction for multiple testing.
2014-08-15 | E-GEOD-38003 | biostudies-arrayexpress