Project description:This study aims to demonstrate the link between epigenome-wide methylation aberrations at birth and genomic transcriptional changes upon allergen sensitization that occur in the neonatal dendritic cells (DC) due to maternal asthma. In an in vivo model reproducing human epidemiology findings, maternal but not paternal asthma predisposes the neonate to increased asthma risk, the effect is allergen-independent and is not genetic or environmental. Earlier we demonstrated that neonates of asthmatic mothers are born with a functional skew in splenic DCs that mediates the early-life asthma origin. These allergen-naive cells convey allergy responses to normal recipients, however minimal to no transcriptional or phenotypic changes were found to explain the functional pro-allergic alterations. In this study we profiled both allergen-naïve dendritic cells, and cells after allergen sensitization in vivo. We found that while allergen-naive DCs from asthma-at-risk neonates have minimal transcriptional change compared to controls, upon allergen sensitization, multiple genes with pre-existing epigenetic alterations show significant transcriptional change. . 24 samples from 2 batches, 3-4 replicates in each of 4 groups
Project description:This study aims to demonstrate the link between epigenome-wide methylation aberrations at birth and genomic transcriptional changes upon allergen sensitization that occur in the neonatal dendritic cells (DC) due to maternal asthma. In an in vivo model reproducing human epidemiology findings, maternal but not paternal asthma predisposes the neonate to increased asthma risk, the effect is allergen-independent and is not genetic or environmental. Earlier we demonstrated that neonates of asthmatic mothers are born with a functional skew in splenic DCs that mediates the early-life asthma origin. These allergen-naive cells convey allergy responses to normal recipients, however minimal to no transcriptional or phenotypic changes were found to explain the functional pro-allergic alterations. In this study we profiled both allergen-naïve dendritic cells, and cells after allergen sensitization in vivo. We found that while allergen-naive DCs from asthma-at-risk neonates have minimal transcriptional change compared to controls, upon allergen sensitization, multiple genes with pre-existing epigenetic alterations show significant transcriptional change. .
Project description:RATIONALE: In a mouse model of maternal transmission of asthma risk (J. Immunol 170:1683, 2003), baby mice of asthmatic (As), but not normal (Nrm), mothers show increased susceptibility to allergy. We previously showed that adoptive transfer to normal baby mice of dendritic cells (DCs) harvested from asthma-susceptible but allergen-naïve neonates reproduces the increased susceptibility to asthma. Hence, the maternal effect is mediated by altered neonatal DCs, which skew immune responses towards a pro-allergic Th2 phenotype. To identify potential molecular mechanisms, we performed epigenomic profiling of isolated neonatal DCs. METHODS: BALB/c mice were sensitized by 2 i.p. injections of ovalbumin (OVA) in alum and repeatedly challenged with OVA aerosols (As) prior to mating with normal males. Purified splenic CD11c+ DCs of 14-day old allergen-naïve offspring from these As and control Nrm mothers were isolated using magnetic beads. Methylation profiles of genomic DNA were obtained using Switchgear epigenomic chip arrays. After normalization and background correction analysis using significance analysis for microarrays (SAM) and ANOVA was performed. RESULTS: We identified 300 to 6000 (depending on stringency) chromosomal regions with significantly different methylation status, (2 â 10 fold). Clustering methods and pathway analysis identified several interrelated gene groups that merit further study. CONCLUSION: Maternal asthma causes multiple significant epigenetic changes in neonatal dendritic cells. Keywords: Dendritic cells, genomic DNA, DNA methylation, allergy, asthma The analysis includes 9 samples of genomic DNA from isolated splenic CD11c+ dendritic cells (>95% pure) per group. The two groups are neonates born to mothers with induced allergy to ovalbumin, and normal control neonates. All neonates are genetically and environmentally identical, and allergen-naive.
Project description:RATIONALE: In a mouse model of maternal transmission of asthma risk (J. Immunol 170:1683, 2003), baby mice of asthmatic (As), but not normal (Nrm), mothers show increased susceptibility to allergy. We previously showed that adoptive transfer to normal baby mice of dendritic cells (DCs) harvested from asthma-susceptible but allergen-naïve neonates reproduces the increased susceptibility to asthma. Hence, the maternal effect is mediated by altered neonatal DCs, which skew immune responses towards a pro-allergic Th2 phenotype. To identify potential molecular mechanisms, we performed epigenomic profiling of isolated neonatal DCs. METHODS: BALB/c mice were sensitized by 2 i.p. injections of ovalbumin (OVA) in alum and repeatedly challenged with OVA aerosols (As) prior to mating with normal males. Purified splenic CD11c+ DCs of 14-day old allergen-naïve offspring from these As and control Nrm mothers were isolated using magnetic beads. Methylation profiles of genomic DNA were obtained using Switchgear epigenomic chip arrays. After normalization and background correction analysis using significance analysis for microarrays (SAM) and ANOVA was performed. RESULTS: We identified 300 to 6000 (depending on stringency) chromosomal regions with significantly different methylation status, (2 – 10 fold). Clustering methods and pathway analysis identified several interrelated gene groups that merit further study. CONCLUSION: Maternal asthma causes multiple significant epigenetic changes in neonatal dendritic cells. Keywords: Dendritic cells, genomic DNA, DNA methylation, allergy, asthma
Project description:Goat’s milk (GM), as compared to Cow’s milk (CM), is easier for human to digest and absorb. GM feeding can improve colic, minor digestive disorders, asthma or eczema in infants. It has been demonstrated that GM have antioxidant and anti-inflammatory effects. Whether GM consumed in pregnant mothers has any immune-modulating effects on their newborns is still unclear. In this study, we used pregnant mothers and their offspring mice to verify this hypothesis. we collected feces of offspring before allergen sensitization (day 0) and two days after i.t. allergen challenge (day 16). Detection of cDNA of feces using Applied Biosystems™ Axiom™ Microbiome Array found the phyla of Bacteroidia, Clostridia, Flavobacteriia, Deferribacteres, Verrucomicrobiae and Gammaproteobacteria as well as some unclassified viruses. Comparison in ratio of Firmicutes to Bacteroidetes (F/B ratio), water-fed (W0) group had higher F/B ratio (0.79) than GM-fed (G0) (0.50) and CM-fed (C0) group (0.54) at Day 0. After HDM allergen sensitization and challenge, there was a remarkable increase of F/B ratio in water-fed mice (0.63 in WN vs. 0.84 in WA), while there was no change of F/B ratio in GM-fed (GN vs. GA) and CM-fed mice (CN vs. CA)
Project description:To determine differential gene expression in peripheral blood of asthmatic individuals undergoing allergen inhalation challenge between early responders (ERs) and dual responders (DRs) following allergen inhalation challenge
Project description:Background: Allergen inhalation challenge in mild asthmatics induces airflow obstruction, airway hyperresponsiveness and inflammation, providing a model for hypothesis-generating experiments to understand regulation of these responses. We have sought to evaluate the peripheral whole blood transcriptome, post-challenge compared to pre-challenge, and to determine the effect of globin mRNA reduction methodology. Methods: Asthmatic subjects (20-60 years of age, with stable, mild allergic asthma, n=17) underwent allergen inhalation challenges. All subjects had an early asthmatic response of ≥ 20% fall in FEV1; most had a late phase response of ≥ 15% fall in FEV1. Blood was collected immediately prior to, and two hours after allergen challenge. Transcriptome analysis was performed using Affymetrix GeneChip® Human Gene 1.0 ST arrays, with and without globin mRNA reduction (PAX-GR and PAX-NGR, respectively) in 4 subjects. Replication studies for expression of nine genes contributing to the top canonical pathway, Nrf2-mediated oxidative stress response pathway, were performed with 5 independent subjects with microarray data, also with the same 4 subjects had microarray results and 8 other independent subjects with QPCR. Data were analyzed using paired t-test and Partek® Genomics Suite™. Results: The number of differentially expressed probe sets from PAX-NGR samples was twice that of PAX-GR samples. Paired analysis of each subjects' pre- and post-sample additionally demonstrated twice the power to detect differentially expressed probe sets. The Nrf2-mediated oxidative stress response pathway was identified as the top canonical pathway in the PAX-NGR samples. ATP-binding cassette sub-family C member 1 (ABCC1) gene was significantly reduced two hours after allergen challenge in the 5 subjects’ microarray dataset and the 2 QPCR replication datasets with P < 0.05. Conclusions: Globin mRNA reduction does not provide benefits to detect differentially expressed genes during allergen inhalation challenge. Allergen inhalation challenge is associated with decreased peripheral blood cell transcript level of ABCC1 gene. 26 array were analyzed. We first identified differentially expreed genes between post- and pre-challenge samples from 4 asthmatic subjects by using globin reduction samples and non-globin reduction samples (16 arrays). Then we replicated our findings using 10 arrays from 5 asthmatic subjects challenged with allergen. Includes 4 normal blood samples.
Project description:BEAS-2B cells, at air liquid interface, were exposed to birch pollen extract or house dust mite extract in a cloud chamber and, later, to UFP rich combustion aerosols in an in vitro exposure system. As control the same exposure was performed without allergen containing extracts. The goal was to understand the effect of allergenic pre-exposure to a UFP rich combustion aerosol exposed cells and their effect on allergic sensitization, using an established model that mimics more closely real life exposures.