ABSTRACT: Antigen specific human conventional T cells (CD154+) or regulatory T cells (CD137+) directed agains A. fumigatus or Birch pollen lysate isolated from Birch pollen allergic patients or healthy controls.
Project description:Foxp3+ regulatory T cells (Treg) play a central role for tolerance against self and innocuous environmental antigens. However, the role of antigen-specificity for Treg-mediated tolerance is only incompletely understood. Here we show by direct ex vivo characterization of human CD4+ T cells, that the response against innocuous airborne antigens, such as plant pollen or fungal spores, is dominated by memory-like antigen-specific Treg. Surprisingly, breakdown of tolerance in atopic donors was not accompanied by a quantitatively or qualitatively altered Treg response, but instead correlated with a striking dichotomy of Treg versus Th2 target specificity. Allergenic proteins, are selectively targeted by Th2 cells, but not Treg. Thus human Treg specific for airborne antigens maintain tolerance at mucosal sites and the failure to generate specific Treg against a subgroup of antigens provides a window of opportunity for allergy development. PBMCs from sex and age matched birch pollen allergic patients and healthy controls, were stimulated (7h) with airborne fungal (A. fumigatus) or birch pollen antigen (birch) and sorted into antigen specific conventional and regulatory T cells according to their expression of CD154+ and CD137+ on CD4+ T cells, respectively. Number of samples per group in parentheses: Healthy controls stimulated with A. fumigatus (n=5), allergic patients stimulated with A. fumigatus (n=6), healthy controls stimulated with birch (n=6), allergic patients stimulated with birch (n=4).
Project description:Immunologic response of two patient categories, birch pollen allergic and non-allergic, to natural pollen exposure (spring vs. winter) quantitated at the level of the transcriptome
Project description:BEAS-2B cells, at air-liquid interface, were exposed to Diesel CAST model aerosol in an vitro exposure system and, later, to native birch pollen using a Pollen Sedimentation Chamber stabilished before. The same exposure was performed, without the primed anthropogenic exposure. The goal was to understand the effect of pre-exposure to a model diesel aerosol in allergic sensitization, using a model stabilished that mimics a real life exposure as closer as possible.
Project description:Six patients with seasonal allergic rhinitis were challenged daily for 8 days with birch pollen extract. A mucosal biopsy was obtained from one nostril at basline (day 0) and from the other nostril after allergen challenge (day 9). The mucosal biopsies were digested into single cells, and then sorted into CD4 T cells and CD45+HLA-DR+ cells. Total RNA was extracted, amplified using whole transcriptome amplification, and gene expression was profiled on microarrays.
Project description:Human BEAS-2B were exposed to whole birch pollen using a Pollen Sedimentation Chamber. The chamber was designed to be able to dose cells to dry whole pollen. The goal was to understand the reaction of human epithelial cells to a human real life pollen exposure.
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.
Project description:To investigate the allergenicity of the major birch pollen allergen Bet v 1 and the impact of known adjuvants coming from pollen, such as lipopolysaccharide (LPS), we performed quantitative proteome analysis of stimulated monocyte-derived dendritic cells (moDCs). Thus, we treated cells with birch pollen extract (BPE), a recombinant variant of Bet v 1 or LPS followed by proteomic profiling by means of high performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS) using isobaric labelling.
Project description:Six patients with seasonal allergic rhinitis were challenged daily for 8 days with birch pollen extract. A mucosal biopsy was obtained from one nostril at basline (day 0) and from the other nostril after allergen challenge (day 9). The mucosal biopsies were digested into single cells, and then sorted into CD4 T cells and CD45+HLA-DR+ cells. Total RNA was extracted, amplified using whole transcriptome amplification, and gene expression was profiled on microarrays. The study design consisted of 6 subjects, 2 cell types (CD4 T cells, CD45+ HLA-DR+ cells), and 2 conditions (baseline, allergen challenge).
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 βâ 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 8Ã60K V2 Microarray Kit).
