Project description:Epigenetic changes including DNA methylation caused by environmental exposures may contribute to the heterogeneous inflammatory response in asthma. Here we investigate alterations in DNA methylation of purified blood monocytes that are associated with inflammatory phenotypes of asthma.
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
Project description:Rhinovirus (RV) infection has been shown to exacerbate asthma. Understanding of the underlying mechanisms by which RV infections provoke airway inflammation and remodeling in asthma may offer significant insight into asthma pathogenesis and exacerbations as well as offer opportunities for improved disease management. Expression analysis of RV A16-treated primary peripheral blood monocytes from human donors was performed to determine what pattern of gene expression is associated with RV infection of monocytes in vitro. Peripheral blood monocytes were isolated from 5 adults. Following overnight incubation in RPMI supplemented with 10% FBS, the monocytes were stimulated with purified major group RV A16 at multiplicity of infection of 10 plaque forming units (pfu) per cell or with growth media alone (mock). Cells were lysed 4 hours after treatment and isolated total RNAs were pooled per treatment and analyzed using the Affymetrix GeneChip HuGeneFL Array (Hu6800, Affymetrix, Santa Clara, CA).
Project description:Exposure of human monocytes to lipopolysaccharide (LPS) or other pathogen-associated molecular pattern (PAMPs) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance (ET). The tolerant state of monocytes is accompanied by cell surface and other glycoprotein expression changes induced by the activation of Toll-like receptors (TLRs). In this study, we aimed to characterize the cellular state of human monocytes stimulated with Gram-positive Staphylococcus aureus and TLR2 ligands. We analyzed gene expression changes induced by S. aureus after 2 and 24 hours by amplicon sequencing (RNA-AmpliSeq) and compared the pro-inflammatory response after 2 hours of stimulation to the to the response in re-stimulation experiments after the first stimulus. In parallel, glycoprotein expression changes in human monocytes after 24 hours of S. aureus stimulation were analyzed by proteomics and compared to stimulation experiments with TLR2 ligands Malp-2 and Pam3Cys and TLR4 ligand LPS. The results demonstrate that monocytes stimulated with S. aureus and TLR ligands entered the tolerant cell state after activation. Compared to TLR agonist mediated activation and tolerization of monocytes, glycoprotein expression changes induced by S. aureus stimulation revealed significant differences in receptor expression profiles. We report a glycoprotein expression profile characteristic for PAMP and S. aureus tolerized human monocytes. Finally, we analyzed peripheral blood monocytes of patients with S. aureus bloodstream infection for inflammatory responses in vitro and for their glycoprotein expression profiles. RNA-AmpliSeq data from patient-derived monocytes demonstrated that the cells were pro-inflammatory responsive to S. aureus stimulation and expressed higher level of CD44 mRNA, while other markers of the tolerant cell state were not detected.
Project description:Rhinovirus (RV) infection has been shown to exacerbate asthma. Understanding of the underlying mechanisms by which RV infections provoke airway inflammation and remodeling in asthma may offer significant insight into asthma pathogenesis and exacerbations as well as offer opportunities for improved disease management. Expression analysis of RV A16-treated primary peripheral blood monocytes from human donors was performed to determine what pattern of gene expression is associated with RV infection of monocytes in vitro.
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.
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
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
Project description:A characteristic feature of asthma is the aberrant accumulation, differentiation or function of memory CD4+ T cells that produce Th2 cytokines (Th2 cells). By comparing gene expression profiles of T cell subsets isolated from peripheral blood of healthy and asthmatic individuals, we identified genes with known and potential roles in the normal differentiation of human Th1 and Th2 cells.
Project description:Different naïve or memory cell subpopulations (i.e., central memory/CM, effector memory/EM, or terminally differentiated effector memory/EMRA) are involved in asthma development, and they display variable levels of the CD26 (dipeptidyl peptidase 4/DPP4). The phenotype and/or severity of the disease could drive to a phenotypic shift in naïve/memory lymphocyte subsets. Therefore, the aim of our work was to evaluate the association of the phenotype and severity of asthma with the relative frequency of CD26-/lo, CD26int, and CD26hi subsets within CD4+ effector T cells (Teff), total CD4- lymphocytes, γδ-T cells, NK cells, and NKT cells. For that, flow cytometry analyses were performed in peripheral blood samples from healthy donors (N=30) and asthma patients (N=119) with different phenotypes/severities. To avoid a priori bias, we have performed a K-means clustering analysis including clinical and flow cytometry data, resulting in four groups, two of them with opposite inflammatory profiles (eosinophilic vs. neutrophilic). CD4-CD26hi cells were reduced in neutrophilic asthma, and negatively correlated with degree of systemic inflammation. Interestingly, the eosinophilic group displayed a general expansion of CD26-/lo lymphocyte subsets. The expansion of CD4+CD26-/lo Teff cells with a TEM/TEMRA phenotype was confirmed in asthma, especially in atopic patients. Further characterisation of this subset by LC MS/MS revealed upregulated levels of innate (e.g., MPO and RNASE2) and cytoskeleton/extracellular matrix (e.g., MMP9, ACTN1) proteins, which matches its terminally differentiated phenotype. Validation by immunofluorescence confirmed the presence of many of these proteins in CD4+ T cells, as well as an enrichment in “flower-like” nuclei and MMP9/RNASE2 levels in CD4+CD26-/lo Teff compared to CD4+ T lymphocytes. Therefore, there is an association between CD26 levels in different lymphocyte subsets and asthma phenotypes/severities. CD4+CD26-/loTEMRA cells expressing innate proteins specific to eosinophils/neutrophils could be relevant in sustaining long-term inflammation in adult allergic asthma.