ABSTRACT: Background Atopic diseases, resulting from hypersensitivity to a wide variety of allergens, affect 10-20% of the population. Immunotherapy is an effective treatment for atopic diseases, but its mechanisms are not fully understood. Objective We studied gene expression profiles in the peripheral blood mononuclear cells and examined whether the individuals with allergic rhinitis have a unique gene expression profile and how the immunotherapy affect the gene expression profiles. Method We used cDNA microarray and “Expression Analysis Systemic Explorer” to examine the gene expression profiles in the peripheral blood mononuclear cells of atopic subjects and other groups. Results We identified a highly conserved gene expression profile in atopic subjects that permitted their accurate segregation from control or autoimmune subjects. A major feature of this profile was the under-expression of a variety of genes that encode proteins required for apoptosis and over-expression of genes that encode proteins critical for stress responses and signal transduction. We also identified 563 genes that can segregate individuals with allergic rhinitis based upon receipt of immunotherapy. Conclusion There is a highly conserved gene expression profile in the peripheral blood mononuclear cells of individuals with allergic rhinitis. This profile can be used to identify individuals with allergic rhinitis and to evaluate responses to immunotherapy. Quantitative endpoints, such as gene expression, may assist clinicians faced with clinical decisions in the diagnosis of patients and the evaluation of response to therapy. The knowledge of the possible genetic basis for immunotherapy efficacy may also lead to novel therapeutic approaches for atopic diseases.
Project description:Timothy grass (TG) pollen is a common seasonal airborne allergen associated with symptoms ranging from mild rhinitis to severe asthma. The aim of this study was to characterize changes in TG-specific T cell responses as a function of seasonality. Peripheral blood mononuclear cells (PBMC) obtained either during the pollen season or out of season, from allergic individuals and non-allergic controls were stimulated either with TG extract or a pool of previously identified immunodominant antigenic regions. PBMC from in season allergic subjects exhibit higher IL-5 and IL-10 responses compared to out of season donors. In the case of non-allergic subjects, as expected we observed lower IL-5 responses and robust production of IFNγ compared to allergic individuals. Strikingly, non-atopic donors exhibited an opposing pattern with decreased immune reactivity in-season. The broad downregulation in non-allergic donors indicates that healthy individuals are not oblivious to allergen exposure but rather react with an active modulation of the responses following the antigenic stimulus provided during the pollen season. Transcriptomic analysis of allergen-specific T cells defined genes modulated in concomitance with allergen exposure and inhibition of responses in non-allergic donors. Magnitude and functionality of T-helper cell responses differ substantially for in season versus out of season in allergic and non-allergic subjects. The results indicate specific and opposing modulation of immune responses following the antigenic stimulation during the pollen season. This seasonal modulation reflects the enactment of specific molecular programs associated with health and allergic disease. Overall design: 11 allergen-specific T cell RNA samples were analyzed: 5 isolated from PBMC of allergic individuals and 6 from non-allergic individuals (considered as the control group).
Project description:The link between upper and lower airways in patients with both asthma and allergic rhinitis is still poorly understood. As the biological complexity of these disorders can be captured by gene expression profiling we hypothesized that the clinical expression of rhinitis and/or asthma is related to differential gene expression between upper and lower airways epithelium. We used micro array to profile gene expression of primary nasal and bronchial epithelial cells from the same individuals and examining the impact of allergic rhinitis with and without concomitant allergic asthma on expression profiles. 17 subjects were included in a cross-sectional study (6 allergic asthma and allergic rhinitis; 5 allergic rhinitis; 6 healthy controls). RNA was extracted from isolated and cultured epithelial cells from bronchial brushes and nasal biopsies, and analyzed by microarray (Affymetrix U133+ PM Genechip Array).
Project description:Analysis of gene-expression profiles by microarrays can be very useful to characterize new potential candidate genes, key regulatory networks, and to define phenotypes or molecular signatures to improve the diagnosis or classification of the disease. We have used this approach in the study of one of the major causes of allergic diseases in Mediterranean countries, the olive pollen response, in order to find differential molecular markers among five clinical groups, Non-allergic, Asymptomatic, Allergic but not to olive pollen, Non-treated, olive pollen allergic patients and Olive pollen allergic patients (under specific-immunotherapy). The results of gene-expression by principal components analysis (PCA) clearly showed five clusters of samples that correlated with the five clinical groups. Analysis of differential gene-expression by multiple testing, and functional analysis by KEGG and Gene-Ontology revealed differential genes and pathways among the 5 clinical groups. The study population comprised 28 subjects, selected from a previous immunological study (Aguerri et al. Eur. J. Inflammation 2012, in press), from Andalusia, who were recruited in 2 olive pollen exposure situations: during (April-June) and outside the pollen season (October-December). We established 5 groups, and 6 subjects from each group were selected for gene-expression analysis: Group 1, non-allergic subjects; Group 2, asymptomatic subjects (diagnosed with olive pollen allergy by skin testing, with no seasonal respiratory symptoms [rhinitis and/or asthma], and who consulted for adverse reaction to drugs); Group 3, patients who were allergic, but not to olive pollen; Group 4, non-treated olive pollen–allergic; and Group 5, olive pollen–allergic patients (receiving olive pollen–specific immunotherapy).The subjects were unrelated and recruited at the Allergy Service of 4 hospitals in Andalusia (Granada, Jaén, Sevilla, and Málaga). Olive pollen–allergic patients fulfilled the following criteria: seasonal rhinitis and/or asthma from April to June, a positive skin prick test result for O. europaea pollen extract (ALK Abelló, Madrid, Spain), and no previous immunotherapy. Informed consent was obtained from each subject. Ethical approval for the study was obtained from the Ethical and Research Committee of the participating hospitals. PBMCs were isolated from heparin-containing peripheral blood samples taken during and outside pollen season, by gradient centrifugation on Lymphoprep (Comercial Rafer, Zaragoza, Spain) following the manufacturer’s instructions.
Project description:Allergic asthma and rhinitis are two common chronic allergic diseases that affect the lungs and nose, respectively. Both diseases share clinical and pathological features characteristic of excessive allergen-induced type 2 inflammation, orchestrated by memory CD4+ T cells that produce type 2 cytokines (TH2 cells). However, a large majority of subjects with allergic rhinitis do not develop asthma, suggesting divergence in disease mechanisms. Since TH2 cells play a pathogenic role in both these diseases and are also present in healthy non-allergic subjects, we performed global transcriptional profiling to determine whether there are qualitative differences in TH2 cells from subjects with allergic asthma, rhinitis and healthy controls. TH2 cells from asthmatic subjects expressed higher levels of several genes that promote their survival as well as alter their metabolic pathways to favor persistence at sites of allergic inflammation. In addition, genes that enhanced TH2 polarization and TH2 cytokine production were also upregulated in asthma. Several genes that oppose T cell activation were downregulated in asthma, suggesting enhanced activation potential of TH2 cells from asthmatic subjects. Many novel genes with poorly defined functions were also differentially expressed in asthma. Thus, our transcriptomic analysis of circulating TH2 cells has identified several molecules that are likely to confer pathogenic features to TH2 cells that are either unique or common to both asthma and rhinitis. RNA-sequencing of circulating TH2 cells isolated from a cohort of patients with allergic rhinitis (25), asthma (40) patients and healthy non allergic subjects (15). Cells were directly isolated from blood by flow cytometry. Total RNA was extracted, messenger RNA was selected and cDNA was amplified linearly with a PCR based method (Picelli et al. 2014). Libraries were prepared using the NexteraXT Illumina sequencing platform.
Project description:Rhinovirus infections are the most common cause of asthma exacerbations. The complex responses by the airway epithelium to rhinovirus can be captured by gene expression profiling. We hypothesized that the upper and lower airway epithelium exhibit differential responses to double-stranded RNA (dsRNA), and that this is modulated by the presence of asthma and allergic rhinitis. Identification of dsRNA-induced gene expression profiles by microarray of primary nasal and bronchial epithelial cells from the same individuals and examining the impact of allergic rhinitis with and without concomitant allergic asthma on expression profiles. Overall design: 17 subjects were included in a cross-sectional study (6 allergic asthma and allergic rhinitis; 5 allergic rhinitis; 6 healthy controls). RNA was extracted from isolated and cultured epithelial cells that were stimulated with Poly(I:C) for 24 hours from bronchial brushes and nasal biopsies, and analyzed by microarray (Affymetrix U133+ PM Genechip Array).
Project description:Rhinovirus infections are the most common cause of asthma exacerbations. The complex responses by the airway epithelium to rhinovirus can be captured by gene expression profiling. We hypothesized that the upper and lower airway epithelium exhibit differential responses to double-stranded RNA (dsRNA), and that this is modulated by the presence of asthma and allergic rhinitis. Identification of dsRNA-induced gene expression profiles by microarray of primary nasal and bronchial epithelial cells from the same individuals and examining the impact of allergic rhinitis with and without concomitant allergic asthma on expression profiles. 17 subjects were included in a cross-sectional study (6 allergic asthma and allergic rhinitis; 5 allergic rhinitis; 6 healthy controls). RNA was extracted from isolated and cultured epithelial cells that were stimulated with Poly(I:C) for 24 hours from bronchial brushes and nasal biopsies, and analyzed by microarray (Affymetrix U133+ PM Genechip Array).
Project description:A Randomized, Placebo-Controlled Trial of Intradermal Allergen Immunotherapy for Grass Pollen Allergy Background: Repeated intradermal injection of grass pollen (nanograms of allergen) suppresses allergen-induced cutaneous late phase responses, in keeping with effects of conventional high dose subcutaneous and sublingual immunotherapy. We evaluated the efficacy and safety of grass pollen intradermal immunotherapy for treatment of allergic rhinitis.Methods: We randomly assigned 93 adults with grass pollen allergic rhinitis to receive 7 pre-seasonal Intradermal allergen immunotherapy injections (containing 7 ng of Phl p 5 major allergen) or histamine control. The primary end point was daily combined symptom-medication scores during the 2013 pollen season. Skin biopsies were taken after the pollen season following an intradermal allergen challenge. Cutaneous late phase responses were measured 4 and either 7, 10 or 13 months post-treatment. Results No difference in the primary endpoint was observed between treatment arms (median difference, 14; 95% confidence interval [CI], -172.5 to 215.1; P=0.80). Amongst secondary endpoints, nasal symptoms measured with daily scores (median difference, 35; 95% CI, 4.0 to 67.5; P=0.03) and visual-analogue scales (median difference, 53; 95% CI, -11.6 to 125.2; P=0.05) were higher in the intradermal treatment group. Intradermal immunotherapy increased serum Phl p-specific IgE (P=0.001) compared to the control arm and T cells cultured from biopsies showed higher and lower surface of surface markers for Type 2 (P=0.04) and Type 1 (P=0.01) T-helper cells, respectively, Interleukin-5 was differentially expressed by microarray (P=0.03). Late phase responses were still inhibited 7 months after treatment (P=0.03) but not at 10-13 months. Conclusions Grass pollen intradermal allergen immunotherapy was not clinically effective but resulted in immunological priming and worsening of allergic rhinitis symptoms. Overall design: T-cells were isolated from skin biopsy by explant culture from control subjects (8) and subjects undergoing IDIT (7). After 7 days T-cells were activated with PMA/Ionomycin. Control subjects were compared with IDIT subjects.
Project description:Analysis of nasal epithelial cells from adult patients with seasonal allergic rhinitis and from non allergic controls. Results provide insight into the molecular mechanisms associated with inflammatory responses in nasal mucosa. Total RNA was obtained from nasal epithelial cells of 7 seasonal allergic rhinitis patients and 5 non-allergic control subjects
Project description:Epigenetic alterations may represent new therapeutic targets and/or biomarkers of allergic rhinitis (AR). Our aim was to examine genome-wide epigenetic changes induced by controlled pollen exposure in the Environmental Exposure Unit (EEU). 38 AR-sufferers and 8 non-allergic controls were exposed to grass pollen for 3h on two consecutive days. We interrogated DNA methylation at baseline and 3h in peripheral blood mononuclear cells (PBMCs) using the Infinium Methylation 450K array. We corrected for demographics, cell composition, and multiple testing (Benjamini-Hochberg), and verified hits using bisulfite PCR-pyrosequencing and qPCR. To extend these findings to a clinically relevant tissue, we investigated DNA methylation and gene expression of mucin 4 (MUC4), in nasal brushings from a separate validation cohort exposed to birch pollen. In PBMCs of allergic rhinitis participants, 42 sites showed significant DNA methylation changes of 2% or greater. DNA methylation changes in tryptase gamma 1 (TPSG1), schlafen 12 (SLFN12) and MUC4 in response to exposure were validated by pyrosequencing. SLFN12 DNA methylation significantly correlated with symptoms (p<0.05), and baseline DNA methylation pattern was found to be predictive of symptom severity upon grass allergen exposure (p<0.05). Changes in MUC4 DNA methylation in nasal brushings in the validation cohort correlated with drop in peak nasal inspiratory flow (Spearman r = 0.314, p = 0.034), and MUC4 gene expression was significantly increased (p<0.0001). This study revealed novel and rapid epigenetic changes upon exposure in a controlled allergen challenge facility, identified baseline epigenetic status as a predictor of symptom severity. Overall design: This cohort consist of genomic DNA extracted from lymphocyte-enriched blood samples from 15 Atopic and 8 non atopic participants. DNA was bisulphite converted and hybridized to the Illumina Infinium HumanMethylation450 Beadchip for genome wide DNA methylation profiling.
Project description:We recruit 4 healthy controls (HC) and 4 patients (P) with seasonal allergic rhinitis before (b) sublingual immunotherapy at the same time and also the same patients after one year (a) of sublingual immunotherapy. Peripheral blood mononuclear cells (PBMCs) obtained from patients and controls were challenged with diluent (D) or allergen (A) extracts from birch pollen at a density of 106 cells/mL for 7 days in RPMI 1640 supplemented with 2 mM L-glutamine, 5% human AB serum, 5 μM β– mercaptoethanol and 50 μg/mL gentamicin. CD4+ T cells were isolated using flow cytometry and the quantity and quality of RNA was examined as described before. Gene expression microarrays (Illumina, San Diego, CA, USA) were performed (by using Agilent G4851B SurePrint G3 Hmn 8×60K V2 Microarray Kit).