Pollen Allergen (pollen + allergen)

Distribution by Scientific Domains

Kinds of Pollen Allergen

  • birch pollen allergen
  • grass pollen allergen
  • major birch pollen allergen


  • Selected Abstracts


    Allergen provocation increases TH2-cytokines and FOXP3 expression in the asthmatic lung

    ALLERGY, Issue 3 2010
    S. Thunberg
    To cite this article: Thunberg S, Gafvelin G, Nord M, Grönneberg R, Grunewald J, Eklund A, van Hage M. Allergen provocation increases TH2-cytokines and FOXP3 expression in the asthmatic lung. Allergy 2010; 65: 311,318. Abstract Background:, Allergic asthma is caused by allergen-specific IgE and T-helper cell (Th) type 2 responses towards airborne allergens. The objective of this study was to investigate local and systemic regulatory mechanisms in the early asthmatic response to bronchial allergen provocation. Methods:, Birch pollen-allergic patients with mild asthma (n = 13) and healthy nonallergic controls (n = 14) were subjected to bronchoalveolar lavage (BAL) and blood sampling. On patients BAL was performed twice: without preceding provocation (,before samples') and 24 h after bronchial provocation with birch pollen allergen. Lymphocytes in BAL and peripheral blood mononuclear cells (PBMCs) were phenotyped by multi-colour flow cytometry and cytokines measured by cytometric bead array. Proliferation and secreted cytokines were analysed in allergen-stimulated PBMCs, CD25+ depleted PBMCs and PBMCs with IL-10 neutralizing antibodies. Results:, The numbers of CD69+ and FOXP3+ lymphocytes were higher in BAL after compared with before allergen provocation in asthmatic patients. Moreover, allergen provocation increased expression of FOXP3 in CD4+CD25bright cells. The cytokine profile in BAL fluid from asthmatics revealed higher levels of IL-5, compared with the controls, and an increase in IL-5, IL-6, IL-9 and IL-10 after allergen provocation. Pollen allergen stimulated PBMC cultures from asthmatic patients produced elevated levels of IL-5 and IL-13 compared with the controls, which were not affected by depletion of CD25+ cells or IL-10 neutralization. Conclusion:, Despite an increase in CD4+CD25bright cells expressing high levels of FOXP3 in response to bronchial allergen provocation, asthmatic patients exhibit enhanced levels of Th2 cytokines in the lung, which may indicate an inability among infiltrating cells to suppress Th2 responses. [source]


    Simultaneous flow cytometric detection of basophil activation marker CD63 and intracellular phosphorylated p38 mitogen-activated protein kinase in birch pollen allergy,

    CYTOMETRY, Issue 1 2009
    Nicolaas E. Aerts
    Abstract Background: Phosphorylation of p38 MAPK is a crucial step in IgE-receptor signaling in basophils. The relation of p38 MAPK to the well-validated diagnostic cell surface marker CD63 has not been evaluated in a clinical allergy model. Methods: Expression of CD63 and phosphorylation of p38 MAPK were analyzed flow cytometrically in anti-IgE-gated basophils from 18 birch pollen allergic patients, five grass pollen allergic patients, and five healthy individuals, after 3 and 20 min of stimulation with recombinant major birch pollen allergen (rBet v 1). Additional time points and the influence of p38 MAPK inhibitor SB203580 were studied in birch pollen allergic patients. Results: Phospho-p38 MAPK and CD63 were expressed dose-dependently in birch pollen allergic patient basophils within 1 minute of rBet v 1 stimulation. P38 MAPK phosphorylation was fastest and subsided gradually while CD63 expression remained elevated for at least 20 min. Inhibition of p38 MAPK significantly inhibited CD63 upregulation. With optimal stimulation of the cells (1 ,g/mL), sensitivity and specificity for the discrimination between patients and a group of control individuals (grass pollen allergic patients and healthy controls) were 94% and 100% for CD63 at 3 and 20 min and for phospho-p38 MAPK at 3 min. Conclusion: Antigen-induced p38 MAPK phosphorylation in human basophils essentially contributes to CD63 upregulation. It is a sensitive and specific intracellular marker for allergy diagnosis and offers new insight into the mechanisms of basophil activation. © 2008 Clinical Cytometry Society [source]


    Cover Picture: Electrophoresis 13'09

    ELECTROPHORESIS, Issue 13 2009
    Article first published online: 20 JUL 200
    Issue 13 is a special issue on "CE and CEC of Amino Acids, Peptides and Proteins" assembling 19 papers on various topics including fast, high efficient and high sensitive "CE and CEC techniques for quality control and purity determination of native and (bio)synthetic amino acids, peptides and proteins, for monitoring of their synthesis, isolation, chemical derivatization and enzymatic digestion and also for investigation of their interactions with other molecules. New methodologies, such as electrodialysis for sample preparation, chiral ligand-exchange CE, immunoaffinity CE, affinity capillary isoelectric focusing, combination of transient isotachophoretic preconcentration with capillary zone electophoresis (CZE) analysis, two-dimensional CE-mass spectrometry (MS) separations and advances in high-sensitive CE-laser induced fluorescence (LIF) and CE-electrochemiluminescence detection schemes, are widely presented here. The applications of CE and CEC methods include chiral analysis of amino acids, determination of low abundant amino acids, peptides and proteins in complex matrices, such as human and animal body fluids and tissue biopsies, and profiling of cell lysates and recombinant proteins, e.g. birch pollen allergen and human interleukin 7. As can be seen from several contributions, preparation of new capillary coatings suppressing the adsorption of peptides and proteins to the fused silica capillary wall in their CZE analyses and/or increasing the selectivity of their open-tubular CEC separations remains a hot topic in the area of CE and CEC developments. In addition, it is shown that through the theoretical modelling of the CZE determined effective electrophoretic mobilities of proteins, the important parameters, such as charge, hydration and shape of their molecules, can be estimated." [source]


    Bet,v,1, the major birch pollen allergen, initiates sensitization to Api,g,1, the major allergen in celery: evidence at the T,cell level

    EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2003
    Barbara Bohle
    Abstract Due to IgE cross-reactivity, birch pollen-allergic individuals frequently develop type,I hypersensitivity reactions to celery tuber. We evaluated the T,cell response to the major allergen in celeriac, Api,g,1, and the cellular cross-reactivity with its homologous major allergen in birch pollen, Bet,v,1. Api,g,1-specific T,cell lines (TCL) and clones (TCC) were established from peripheralblood mononuclear cells of allergic patients. Epitope mapping of Api,g,1 with overlapping Api,g,1-derived peptides revealed one dominant T,cell-activating region, Api,g,1109,126. TCL and TCC generated with Api,g,1 cross-reacted with the birch pollen allergen and, although initially stimulated with the food allergen, cellular responses to Bet,v,1 were stronger than to Api,g,1. Epitopemapping with Bet,v,1-derived peptides revealed that T,cells specific for several distinct epitopes distributed over the complete Bet,v,1 molecule could be activated by Api,g,1. Bet,v,1109,126 was identified as the most important T,cell epitope for cross-reactivity with Api,g,1. This epitope shares 72% amino acid sequence similarity with the major T,cell-activating region of the food allergen, Api,g,1109,126. Our data provide evidence that humoral as well as cellular reactivity to the major celery allergen is predominantly based on cross-reactivity with the major birch pollen allergen. The activation of Bet,v,1-specific Th2 cells by Api,g,1, in particular outside the pollen season, may have consequences for birch pollen-allergic individuals. [source]


    The allergen Bet v 1 in fractions of ambient air deviates from birch pollen counts

    ALLERGY, Issue 7 2010
    J. T. M. Buters
    To cite this article: Buters JTM, Weichenmeier I, Ochs S, Pusch G, Kreyling W, Boere AJF, Schober W, Behrendt H. The allergen Bet v 1 in fractions of ambient air deviates from birch pollen counts. Allergy 2010; 65: 850,858. Abstract Background:, Proof is lacking that pollen count is representative for allergen exposure, also because allergens were found in nonpollen-bearing fractions of ambient air. Objective:, We monitored simultaneously birch pollen and the major birch pollen allergen Bet v 1 in different size fractions of ambient air from 2004 till 2007 in Munich, Germany. Methods:, Air was sampled with a ChemVol® high-volume cascade impactor equipped with stages for particulate matter (PM)>10 ,m, 10 ,m>PM>2.5 ,m, and 2.5 ,m>PM>0.12 ,m. Allergen was determined with a Bet v 1-specific ELISA. Pollen count was assessed with a Burkard pollen trap. We also measured the development of allergen in pollen during ripening. Results:, About 93 ± 3% of Bet v 1 was found in the PM,>,10 ,m fraction, the fraction containing birch pollen. We did not measure any Bet v 1 in 2.5 ,m,>,PM,>,0.12 ,m. Either in Munich no allergen was in this fraction or the allergen was absorbed to diesel soot particles that also deposit in this fraction. Pollen released 115% more Bet v 1 in 2007 than in 2004. Also within 1 year, the release of allergen from the same amount of pollen varied more than 10-fold between different days. This difference was explained by a rapidly increasing expression of Bet v 1 in pollen in the week just before pollination. Depending on the day the pollen is released during ripening, its potency varies. Conclusion:, In general, pollen count and allergen in ambient air follow the same temporal trends. However, because a 10-fold difference can exist in allergen potency of birch pollen, symptoms might be difficult to correlate with pollen counts, but perhaps better with allergen exposure. [source]


    Association of allergic patients' phenotypes with IgE reactivity to recombinant pollen marker allergens

    ALLERGY, Issue 3 2010
    A. Twardosz-Kropfmüller
    To cite this article: Twardosz-Kropfmüller A, Singh MB, Niederberger V, Horak F, Kraft D, Spitzauer S, Valenta R, Swoboda I. Association of allergic patients' phenotypes with IgE reactivity to recombinant pollen marker allergens. Allergy 2010; 65: 296,303. Abstract Background:, During the last decade allergen molecules from several allergen sources have been produced by recombinant DNA technology. The aim of this study was to investigate whether IgE reactivity to recombinant pollen allergens with broad and narrow cross-reactivity is associated with clinical phenotypes of allergic sensitization. Methods:, Serum IgE reactivity to a panel of six recombinant birch and grass pollen allergens was measured by ELISA in pollen sensitized patients from Central Europe to define groups of patients with exclusive IgE reactivity to rBet v 1, with exclusive reactivity to major grass pollen allergens (rPhl p 1, rPhl p 2, rPhl p 5) and with IgE reactivity to cross-reactive pollen allergens (rBet v 2, rPhl p 7). Patients' clinical phenotypes were recorded. IgE responses to tree, grass and weed pollen as well as plant food extracts were evaluated in vitro by CAP-FEIA and clinical sensitivities were confirmed in vivo by skin prick testing. Results:, IgE reactivity to the recombinant major birch pollen allergen, rBet v 1, was associated with sensitization to pollen from birch, taxonomically related trees and to certain plant-derived food. Reactivity to the recombinant timothy grass pollen allergens, rPhl p 1, rPhl p 2, rPhl p 5, indicated sensitization to pollen from grasses. Patients reacting with the highly cross-reactive allergen rPhl p 7 were polysensitized to pollen from unrelated trees, grasses and weeds and rBet v 2-positive patients were polysensitized to pollen and plant-derived food from unrelated plants. Conclusions:, IgE reactivity to recombinant marker allergens is associated with clinical phenotypes of allergic sensitization and may be useful for the selection of treatment strategies. [source]


    Allergen provocation increases TH2-cytokines and FOXP3 expression in the asthmatic lung

    ALLERGY, Issue 3 2010
    S. Thunberg
    To cite this article: Thunberg S, Gafvelin G, Nord M, Grönneberg R, Grunewald J, Eklund A, van Hage M. Allergen provocation increases TH2-cytokines and FOXP3 expression in the asthmatic lung. Allergy 2010; 65: 311,318. Abstract Background:, Allergic asthma is caused by allergen-specific IgE and T-helper cell (Th) type 2 responses towards airborne allergens. The objective of this study was to investigate local and systemic regulatory mechanisms in the early asthmatic response to bronchial allergen provocation. Methods:, Birch pollen-allergic patients with mild asthma (n = 13) and healthy nonallergic controls (n = 14) were subjected to bronchoalveolar lavage (BAL) and blood sampling. On patients BAL was performed twice: without preceding provocation (,before samples') and 24 h after bronchial provocation with birch pollen allergen. Lymphocytes in BAL and peripheral blood mononuclear cells (PBMCs) were phenotyped by multi-colour flow cytometry and cytokines measured by cytometric bead array. Proliferation and secreted cytokines were analysed in allergen-stimulated PBMCs, CD25+ depleted PBMCs and PBMCs with IL-10 neutralizing antibodies. Results:, The numbers of CD69+ and FOXP3+ lymphocytes were higher in BAL after compared with before allergen provocation in asthmatic patients. Moreover, allergen provocation increased expression of FOXP3 in CD4+CD25bright cells. The cytokine profile in BAL fluid from asthmatics revealed higher levels of IL-5, compared with the controls, and an increase in IL-5, IL-6, IL-9 and IL-10 after allergen provocation. Pollen allergen stimulated PBMC cultures from asthmatic patients produced elevated levels of IL-5 and IL-13 compared with the controls, which were not affected by depletion of CD25+ cells or IL-10 neutralization. Conclusion:, Despite an increase in CD4+CD25bright cells expressing high levels of FOXP3 in response to bronchial allergen provocation, asthmatic patients exhibit enhanced levels of Th2 cytokines in the lung, which may indicate an inability among infiltrating cells to suppress Th2 responses. [source]


    Time-series nasal epithelial transcriptomics during natural pollen exposure in healthy subjects and allergic patients

    ALLERGY, Issue 2 2010
    P. Mattila
    To cite this article: Mattila P, Renkonen J, Toppila-Salmi S, Parviainen V, Joenväärä S, Alff-Tuomala S, Nicorici D, Renkonen R. Time-series nasal epithelial transcriptomics during natural pollen exposure in healthy subjects and allergic patients. Allergy 2010; 65: 175,183. Abstract Background:, The role of epithelium has recently awakened interest in the studies of type I hypersensitivity. Objective:, We analysed the nasal transcriptomics epithelial response to natural birch pollen exposure in a time series manner. Methods:, Human nasal epithelial cell swabs were collected from birch pollen allergic patients and healthy controls in winter season. In addition, four specimens at weekly intervals were collected from the same subjects during natural birch pollen exposure in spring and transcriptomic analyses were performed. Results:, The nasal epithelium of healthy subjects responded vigorously to allergen exposure. The immune response was a dominating category of this response. Notably, the healthy subjects did not display any clinical symptoms regardless of this response detected by transcriptomic analysis. Concomitantly, the epithelium of allergic subjects responded also, but with a different set of responders. In allergic patients the regulation of dyneins, the molecular motors of intracellular transport dominated. This further supports our previous hypothesis that the birch pollen exposure results in an active uptake of allergen into the epithelium only in allergic subjects but not in healthy controls. Conclusion:, We showed that birch pollen allergen causes a defence response in healthy subjects, but not in allergic subjects. Instead, allergic patients actively transport pollen allergen through the epithelium to tissue mast cells. Our study showed that new hypotheses can arise from the application of discovery driven methodologies. To understand complex multifactorial diseases, such as type I hypersensitivity, this kind of hypotheses might be worth further analyses. [source]


    Micro-arrayed wheat seed and grass pollen allergens for component-resolved diagnosis

    ALLERGY, Issue 7 2009
    C. Constantin
    Background:, Wheat is a potent allergen source and can cause baker's asthma, food and pollen allergy. The aim of the study was to develop an allergen micro-array for differential diagnosis of baker's asthma, wheat-induced food allergy and grass pollen allergy. Methods:, We analysed the immunoglobulin-E reactivity profiles of patients suffering from baker's asthma, wheat-induced food allergy and grass pollen allergy to micro-arrayed recombinant wheat flour allergens and grass pollen allergens and compared these results with clinical results and diagnostic tests based on crude wheat flour, wheat pollen and grass pollen allergen extracts. Results:, We identified recombinant wheat flour allergens, which are specifically recognized by patients suffering from baker's asthma, but not from patients with food allergy to wheat or pollen allergy. rPhl p 1 and rPhl p 5 were identified as marker allergens specific for grass pollen allergy. They can be used to replace grass pollen extracts for allergy diagnosis and to identify grass pollen allergic patients among patients suffering from baker's asthma and wheat-induced food allergy. Profilin was identified as a cross-reactive allergen recognized by patients suffering from baker's asthma, food and pollen allergy. Conclusions:, Our results indicate that it will be possible to design serological tests based on micro-arrayed recombinant wheat seed and grass pollen allergens for the discrimination of baker's asthma, wheat-induced food allergy and grass pollen allergy. [source]


    Birch pollen allergen Bet v 1 binds to and is transported through conjunctival epithelium in allergic patients

    ALLERGY, Issue 6 2009
    J. Renkonen
    Background:, Previous work in type-I pollen allergies has mainly focused on lymphocytes and immune responses. Here, we begin to analyse with a systems biology view the differences in conjunctival epithelium obtained from healthy and allergic subjects. Methods:, Transcriptomics analysis combined with light and electron microscopic analysis of birch pollen allergen Bet v 1 located within conjunctival epithelial cells and tissues from birch allergic subjects and healthy controls was carried out. Results:, Bet v 1 pollen allergen bound to conjunctival epithelial cells within minutes after the exposure even during the nonsymptomatic winter season only in allergic, but not in healthy individuals. Light- and electron microscopy showed that Bet v 1 was transported through the epithelium within lipid rafts/caveolae and reached mast cells only in allergic patients, but not in healthy individuals. Transcriptomics yielded 22 putative receptors expressed at higher levels in allergic epithelium compared with healthy specimens. A literature search indicated that out of these receptors, eight (i.e. 37%) were associated with lipid rafts/caveolae, which suggested again that Bet v 1 transport is lipid raft/caveola-dependent. Conclusions:, We show a clear difference in the binding and uptake of Bet v 1 allergen by conjunctival epithelial cells in allergic vs healthy subjects and several putative lipid raft/caveolar receptors were identified, which could mediate or be co-transported with this entry. The application of discovery driven methodologies on human conjunctival epithelial cells and tissues can provide new hypotheses worth a further analysis to the molecular mechanisms of a complex multifactorial disease such as type-I birch pollen allergy. [source]


    Reducing allergenicity by altering allergen fold: a mosaic protein of Phl p 1 for allergy vaccination

    ALLERGY, Issue 4 2009
    T. Ball
    Background:, The major timothy grass pollen allergen, Phl p 1, resembles the allergenic epitopes of natural group I grass pollen allergens and is recognized by more than 95% of grass-pollen-allergic patients. Our objective was the construction, purification and immunologic characterization of a genetically modified derivative of the major timothy grass pollen allergen, Phl p 1 for immunotherapy of grass pollen allergy. Methods:, A mosaic protein was generated by PCR-based re-assembly and expression of four cDNAs coding for Phl p 1 fragments and compared to the Phl p 1 wild-type by circular dichroism analysis, immunoglobulin E (IgE)-binding capacity, basophil activation assays and enzyme-linked immunosorbent assay competition assays. Immune responses to the derivative were studied in BALB/c mice. Results:, Grass-pollen-allergic patients exhibited greater than an 85% reduction in IgE reactivity to the mosaic as compared with the Phl p 1 allergen and basophil activation experiments confirmed the reduced allergenic activity of the mosaic. It also induced less Phl p 1-specific IgE antibodies than Phl p 1 upon immunization of mice. However, immunization of mice and rabbits with the mosaic induced IgG antibodies that inhibited patients' IgE-binding to the wild-type allergen and Phl p 1-induced degranulation of basophils. Conclusion:, We have developed a strategy based on rational molecular reassembly to convert one of the clinically most relevant allergens into a hypoallergenic derivative for allergy vaccination. [source]


    Symptoms to pollen and fruits early in life and allergic disease at 4 years of age

    ALLERGY, Issue 11 2008
    X.-M. Mai
    Background:, The predictive value of reported early symptoms to pollen or fruits on later allergic disease is unclear. Our aim is to evaluate if symptoms to pollen and/or to fruits early in life are associated with allergic disease and sensitization to pollen at 4 years. Methods:, The study included 3619 children from the Barn (Children), Allergy, Milieu, Stockholm, Epidemiology project (BAMSE) birth cohort. Reported symptoms of wheeze, sneeze or rash to birch, grass or weed, symptoms (vomiting, diarrhea, rash, facial edema, sneeze, or wheeze) to fruits including tree-nuts at 1 or 2 years of age, and definitions of asthma, rhinitis and eczema at 4 years were derived from questionnaire data. Sensitization to pollen allergens was defined as allergen-specific IgE-antibodies to any pollen (birch/timothy/mugwort) ,0.35 kUA/l. Results:, At 1 or 2 years of age, 6% of the children were reported to have pollen-related symptoms, 6% had symptoms to fruits, and 1.4% to both pollen and fruits. Children with symptoms to both pollen and fruits at 1 or 2 years of age had an increased risk for sensitization to any pollen allergen at age 4 (ORadj = 4.4, 95% CI = 2.1,9.2). This group of children also had a substantially elevated risk for developing any allergic disease (asthma, rhinitis, or eczema) at 4 years irrespective of sensitization to pollen (ORadj = 8.6, 95% CI = 4.5,16.4). Conclusions:, The prevalence of reported symptoms to pollen and fruits is very low in early childhood. However, children with early symptoms to both pollen and fruits appear to have a markedly elevated risk for allergic disease. [source]


    The impact of pollen-related food allergens on pollen allergy

    ALLERGY, Issue 1 2007
    B. Bohle
    Patients with birch pollen allergy frequently develop hypersensitivity reactions to certain foods, e.g. apples, celery, carrots and hazelnuts. These reactions are mainly caused by IgE-antibodies specific for the major birch pollen allergen, Bet v 1, which cross-react with homologous proteins in these foods. Analyzing the T-cell response to Bet v 1-related food allergens revealed that these dietary proteins contain several distinct T-cell epitopes and activate Bet v 1-specific T cells to proliferate and produce cytokines. Several of these cross-reactive T-cell epitopes were not destroyed by simulated gastrointestinal digestion of food allergens and stimulated Bet v 1-specific T cells despite nonreactivity with IgE antibodies. Similarly, cooked food allergens did not elicit IgE-mediated symptoms (oral allergy syndromes) but caused T-cell-mediated late-phase reactions (deterioration of atopic eczema) in birch pollen-allergic patients with atopic dermatitis because thermal processing affected their conformational structure and not the primary amino acid sequence. Thus, T-cell cross-reactivity between Bet v 1 and related food allergens occurs independently of IgE-cross-reactivity in vitro and in vivo. We speculate that symptom-free consumption of pollen-related food allergens may have implications for the pollen-specific immune response of allergic individuals. [source]


    T lymphocytes expressing CCR3 are increased in allergic rhinitis compared with non-allergic controls and following allergen immunotherapy

    ALLERGY, Issue 1 2007
    J. N. Francis
    Background:, In T cell-associated allergic inflammation, homing of T-helper 2 (Th2) effector cells to mucosal sites may be influenced by chemokine receptor expression. Previous studies have identified CCR3 and CCR4 as putative markers of Th2 cells and CCR5 and CXCR3 as markers of Th1 cells. The aim of this study was to assess differential chemokine receptor expression from symptomatic atopic grass pollen-sensitive subjects, compared with patients on high-dose allergen injection immunotherapy (IT) and healthy controls. Methods:, We examined chemokine receptor expression (CCR1,7 and CXCR1,4) by flow cytometry of peripheral blood CD4+ and CD8+ T cells. We also depleted peripheral blood mononuclear cell (PBMC) populations of CCR3+ CD4+ cells by magnetic bead separation and cells were stimulated with grass pollen allergen for 6 days. Cytokine production was measured by enzyme-linked immunosorbent assay. Results:, On freshly isolated PBMC, atopic individuals exhibited increased numbers of CCR3+ CD4+ cells compared with normal controls (P < 0.01). CCR3 expression in IT patients was reduced compared with matched atopic rhinitic controls (P < 0.05) and comparable with that observed in normal subjects. Depletion of CCR3+ CD4+ cells from allergen-stimulated PBMC cultures resulted in decreased interleukin (IL)-5 production compared with whole CD4+ populations (P < 0.05). Freshly isolated CCR3+ CD4+ cells have significantly higher intracellular IL-4 and lower IFN- , levels than CCR3, CD4+ cells. CD4+ T cells cultured from both peripheral cells and nasal biopsies demonstrated increased expression of CCR3 in the presence of IL-4 (P < 0.05). Conclusion:, CCR3+ CD4+ T cells are increased in allergic rhinitis, are reduced by allergen IT, have a Th2 phenotype and contribute to allergen-specific responses. Strategies against CCR3+ T cells may be effective in human allergic diseases. [source]


    Hypoallergenic mutants of Ole e 1, the major olive pollen allergen, as candidates for allergy vaccines

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2007
    E. G. Marazuela
    Summary Background The C-terminal region of Ole e 1, a major allergen from olive pollen, is a dominant IgE-reactive site and offers a target for site-directed mutagenesis to produce variants with reduced IgE-binding capability. Objective To evaluate in vitro and in vivo the immunogenic properties of three engineered derivatives of Ole e 1. Methods One point (Y141A) and two deletion (135,10 and 140,5) mutants were generated by site-directed mutagenesis of Ole e 1-specific cDNA and produced in Pichia pastoris. Ole e 1 mutants were analysed for IgE reactivity by ELISA using sera from olive pollen-allergic patients. Their allergenicity was also investigated in both a mouse model of allergic sensitization and in basophil activation assays. IgG1 response was assayed by immunoblotting and competitive ELISA. T cell reactivity was evaluated by proliferation assays and cytokine production in splenocyte cultures. Results The 135,10 mutant showed the strongest reduction in the IgE-binding capability of sera from olive pollen-allergic patients. Rat basophil leukaemia assays identified the deletion mutant 135,10 as the variant with the lowest ,-hexosaminidase-releasing capacity. Furthermore, the same 135,10 mutant induced the lowest IgE levels in a BALB/c mouse model of sensitization. All Ole e 1 mutants retained their allergen-specific T cell reactivity. Immunization of mice with the mutants induced IgG1 antibodies, which cross-reacted with Ole e 1 and Ole e 1-like allergens from ash, lilac and privet pollens. The ability of the human IgE to block the binding of anti-Ole e 1 mutant-specific mouse IgG1 antibodies to natural Ole e 1 demonstrated that Ole e 1 mutants are able to induce in vivo antibodies reactive to the natural allergen. Conclusion The 135,10 mutant with reduced allergenicity, intact T cell reactivity and capacity to induce blocking antibodies could provide a suitable candidate vaccine for efficient and safer therapy of olive pollen allergy. [source]


    Characterization of the T cell response to the major hazelnut allergen, Cor a 1.04: evidence for a relevant T cell epitope not cross-reactive with homologous pollen allergens

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2005
    B. Bohle
    Summary Background IgE antibodies specific for the major birch-pollen allergen, Bet v 1, cross-react with homologous allergens in particular foods, e.g. apples, carrots and hazelnuts. In a high number of tree pollen-allergic individuals, this cross-reactivity causes clinical symptoms, commonly known as the ,birch-fruit-syndrome'. Objective To characterize the T cell response to the Bet v 1-related major allergen in hazelnuts, Cor a 1.04, and its cellular cross-reactivity with Bet v 1 and the homologous hazel pollen allergen, Cor a 1. Methods Using recombinant Cor a 1.04, T cell lines (TCL) and T cell clones (TCC) were established from peripheral blood mononuclear cells of tree pollen-allergic patients with associated food allergy. T cell epitopes were determined using overlapping synthetic peptides in Cor a 1.04-reactive TCL and TCC. In parallel, reactivity to Bet v 1 and Cor a 1 was tested. Results In total, 20 distinct T cell epitopes on the hazelnut allergen were identified. Several Cor a 1.04-specific TCL and TCC reacted with pollen allergens albeit less pronounced than with the hazelnut allergen. Several Cor a 1.04-specific TCC did not react with pollen allergens. Interestingly, these clones were found to react with the Bet v 1-related major allergen in carrots, Dau c 1. The cellular cross-reactivity between both food allergens could be associated with the most frequently recognized T cell epitope of Cor a 1.04, Cor a 1.04142,153. Conclusions The major hazelnut allergen cross-reacts with the major allergens of birch and hazel pollen but apparently contains a relevant T cell epitope not shared with pollen allergens. Our finding may have important implications for the specific immunotherapy of tree pollen-allergic patients suffering from concomitant hazelnut allergy. [source]


    Effects of lysed Enterococcus faecalis FK-23 on allergen-induced serum antibody responses and active cutaneous anaphylaxis in mice

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2004
    T. Shimada
    Summary Background Our previous studies have presented evidence that lysed Enterococcus faecalis FK-23 (LFK), a lysozyme and heat-treated probiotic product, can inhibit allergen-induced local accumulation of eosinophils in mice. Objective The purpose of this experimental study was to evaluate the influence of orally administrated LFK on the host immune responses. Methods BALB/c mice were sensitized subcutaneously, and challenged intraperitoneally by cedar pollen allergen. Blood and spleen samples were collected after oral administration of LFK 60 mg/day for 21 days. The serum levels of total and allergen-specific IgE and IgG2a antibodies and the production of IL-4, IL-5 and IFN-, generated by allergen-stimulated cultured splenocytes were determined. Additionally, the effect of LFK on active cutaneous anaphylaxis (ACA) induced by ovalbumin (OVA) challenge in mice was measured after 28 days LFK treatment. Results No significant differences in serum immunoglobulin levels, as well as in cytokine production of splenocytes were observed between LFK-treated and control mice (P>0.05). There was, however, an increasing tendency of allergen-specific IgG2a level in mice after LFK treatment for 21 days compared with controls (P=0.060). Furthermore, the serum ratio of specific IgE to IgG2a was found to be significantly decreased in the LFK group (P=0.005). In addition, a significant inhibition of OVA-induced ACA reaction was observed in mice that had been fed for 28 days with LFK compared with control mice (P=0.008). Conclusion These results suggest that LFK shows an anti-inflammatory effect, which may be part of the mechanism for protection against IgE-mediated allergy. [source]


    Analysis of sequential immunoglobulin E-binding epitope of Japanese cedar pollen allergen (Cry j 2) in humans, monkeys and mice

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 2 2003
    Y. Tamura
    Summary Background Japanese cedar (Cryptomeria japonica; CJ) pollinosis has been reported to occur naturally in Japanese monkeys (Macaca fuscata) as well as in humans. Most human patients and monkeys with pollinosis have specific IgE for Cry j 2, a major allergen of CJ pollen. Objective The main purpose of this study was to identify IgE B cell epitopes of Cry j 2 using a synthetic peptide in humans, monkeys and mice. Methods We synthesized 38 overlapping peptides that span the entire length of Cry j 2. We examined the B cell epitopes of Cry j 2 that are recognized by IgE in the sera of human patients and monkeys with pollinosis and immunized mice using synthetic peptides of Cry j 2. We also examined the reaction of Cry j 2-specific mouse monoclonal IgG antibodies to the peptides. Furthermore, we conducted a histamine release assay with leucocytes from a pollinosis patient using human serum albumin (HSA) conjugated with the peptides as a B cell epitope. Results We found that 16 of the 20 pollinosis patients who had specific IgE to Cry j 2 also exhibited IgE reaction with some Cry j 2 peptides. Of these 16 patients, 10 exhibited IgE reaction with Cry j 2 peptide no. 13 (121GQCKWVNGREICNDRDRPTA140). Five of the seven monkeys with CJ pollinosis exhibited a reaction with peptide no. 13. Furthermore, IgE in mice immunized with Cry j 2 and two mouse monoclonal IgG antibodies reacted with peptide no. 13. Peptide no. 13-conjugated HSA showed the release of histamine from basophils. Furthermore, to determine the minimum epitope in peptide no. 13, we conducted an enzyme-linked immunosorbent assay inhibition test. The core of the epitope in humans, monkeys and mice was 124KWVNGREI131. Conclusion We found that 124KWVNGREI131 is an important B cell epitope recognized by IgE in humans, monkeys and mice. [source]


    Nasal challenges with recombinant derivatives of the major birch pollen allergen Bet v 1 induce fewer symptoms and lower mediator release than rBet v 1 wild-type in patients with allergic rhinitis

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2002
    M. Van Hage-Hamsten
    Summary Background Genetic engineering of the major birch pollen allergen (Bet v 1) has led to the generation of recombinant Bet v 1 derivatives with markedly reduced IgE-binding capacity, but with retained T cell activating ability. Objective To compare the mucosal reactivity to rBet v 1 derivatives with rBet v 1 wild-type as basis for new therapeutic strategies for birch pollen allergy based on mucosal tolerance induction. Methods Outside the pollen season, 10 patients with birch pollen allergic rhinitis and mild asthma underwent four nasal challenge-sessions in a randomized, double-blind, and cross-over design, employing increasing doses of rBet v 1 fragment mix, rBet v 1 trimer, rBet v 1 wild-type and diluent (albumin). Nasal lavage fluids (NAL) were collected before the challenge-series as well as 10 min, 4 and 24 h thereafter. Nasal lavage fluid levels of tryptase as well as EPO and ECP were measured as indices of mast cell and eosinophil activity, respectively. Results All 10 patients tolerated the highest accumulated dose, 8.124 µg, when challenged with rBet v 1 trimer, eight with rBet v 1 fragments compared to one when challenged with rBet v 1 wild-type. No late phase reactions were observed. The change in tryptase levels (pre-challenge vs. 10 min) was significantly lower after challenges with rBet v 1 trimer and rBet v 1 fragments than with rBet v 1 wild-type. The change in EPO/ECP concentration pre-challenge versus 4 h post-challenge was lower for rBet v 1 trimer and the change was significantly lower when pre-challenge versus 24 h post-challenge to rBet v 1 fragments and rBet v 1 wild-type was examined. Conclusion The derivatives induced significantly fewer symptoms and lower mast cell and eosinophil activation than rBet v 1 wild-type upon application to the nasal mucosa. They could in the future be candidates for immunotherapy based on mucosal tolerance induction. [source]


    Quantification of group 5 grass pollen allergens in house dust

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 11 2000
    B. Fahlbusch
    Background It is widely known and accepted that grass pollen is a major outdoor cause of hay fever. However, it is of virtual importance for grass pollen allergic patients with symptoms all the year round to know the concentration of grass pollen allergens in their homes. Objective The main objective of this study was to quantify the amount of grass pollen allergen in mass units (,g Phl p 5) in dust settled indoors and to detect the distribution of allergenic activity in different sampling locations of homes. Furthermore, we studied the seasonal fluctuation of allergen content in dust samples. Methods We adapted the two site binding assay for detection of group 5 grass pollen allergens in samples from randomly selected homes in Hamburg (n = 371), Erfurt (n = 396), Hettstedt (n = 353), Zerbst (n = 289) and Bitterfeld (n = 226), Germany. Dust samples were collected from floor of living room (LR), bedroom (BR) or children's room (CR) and mattress (MA) during period of June 1995 to August 1998. The amount of the major grass group 5 allergens was detected in ,g/g dust. Results Phl p 5 was detected in 67% of the samples analysed (n = 4760). The range was between undetectable (< 0.03 ,g/g dust) and 81 ,g/g dust. Phl p 5 levels were significantly higher in the dust from LR (geometric mean 0.117 ,g/g dust) or BR/CR floors (geometric mean 0.098 ,g/g dust) than in mattresses (geometric mean 0.043 ,g/g dust). We observed seasonal fluctuation of indoor Phl p 5 levels with peak in June but also annual differences. Thus Phl p 5 content indoors reflects also the different quantities of pollen counts of annual courses. During pollination period we found two times higher Phl p 5 levels (0.172 ,g/g dust, P < 0.001) than outside of grass pollination season (0.095 ,g/g dust). The indoor Phl p 5 levels outside of season seem to be independent of pollination before. We suppose that settled pollen grains or allergenic material from outdoor particles carried indoors via footwear and clothes accumulates in house dust. Conclusion Although we not known how the allergens in settled dust are equilibrated with those in the air, the considerable high level of Phl p 5 in indoor dust even during periods when no grass pollen is present in the atmosphere may be an important cause of pollen-allergy symptoms outside of season. [source]


    Identification and characterization of a group 2 conifer pollen allergen from Chamaecyparis obtusa, a homologue of Cry j 2 from Cryptomeria japonica

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 4 2000
    Yasueda
    Background Not only Cryptomeria japonica (Japanese cedar) pollen but also that of Chamaecyparis obtusa (Japanese cypress) induces the allergic symptoms of Japanese cedar pollinosis. However, allergens from C. obtusa pollen have not been as well characterized as those from C. japonica pollen. Objective We sought to identify and characterize a homologue of the second major allergen of C. japonica pollen, Cry j 2, from the pollen of C. obtusa. Methods An allergen homologous to Cry j 2 was identified in C. obtusa pollen extract by immunoblot analysis, probed with anti-Cry j 2 monoclonal antibodies and purified by a series of column chromatographic steps. Results The allergen isolated from the extract showed a slightly diffuse band of 45 kDa and closely spaced double-bands of 42 and 45 kDa on SDS-PAGE, under reducing and non-reducing conditions, respectively; the bands were approximately 5,7 kDa larger than those of Cry j 2. In 24 of 30 residues, the N-terminal amino acid sequence of the allergen was identical with corresponding sequence in Cry j 2. Most patients with pollinosis who were IgE antibody-positive to Cry j 2 were shown to be IgE antibody-positive to this allergen, and the IgE antibody levels to both allergens were highly correlated. Conclusion The results indicate that the allergen isolated from C. obtusa pollen in this study is a homologue of Cry j 2. The allergen was designated as Cha o 2 according to the WHO/IUIS Allergen Nomenclature Subcommittee recommendation. [source]


    Micro-arrayed wheat seed and grass pollen allergens for component-resolved diagnosis

    ALLERGY, Issue 7 2009
    C. Constantin
    Background:, Wheat is a potent allergen source and can cause baker's asthma, food and pollen allergy. The aim of the study was to develop an allergen micro-array for differential diagnosis of baker's asthma, wheat-induced food allergy and grass pollen allergy. Methods:, We analysed the immunoglobulin-E reactivity profiles of patients suffering from baker's asthma, wheat-induced food allergy and grass pollen allergy to micro-arrayed recombinant wheat flour allergens and grass pollen allergens and compared these results with clinical results and diagnostic tests based on crude wheat flour, wheat pollen and grass pollen allergen extracts. Results:, We identified recombinant wheat flour allergens, which are specifically recognized by patients suffering from baker's asthma, but not from patients with food allergy to wheat or pollen allergy. rPhl p 1 and rPhl p 5 were identified as marker allergens specific for grass pollen allergy. They can be used to replace grass pollen extracts for allergy diagnosis and to identify grass pollen allergic patients among patients suffering from baker's asthma and wheat-induced food allergy. Profilin was identified as a cross-reactive allergen recognized by patients suffering from baker's asthma, food and pollen allergy. Conclusions:, Our results indicate that it will be possible to design serological tests based on micro-arrayed recombinant wheat seed and grass pollen allergens for the discrimination of baker's asthma, wheat-induced food allergy and grass pollen allergy. [source]


    Administration regimens for sublingual immunotherapy to pollen allergens: What do we know?

    ALLERGY, Issue 6 2009
    C. Lombardi
    The modalities of administration of sublingual immunotherapy (SLIT), including dosing, build-up phase, duration of the treatment, and frequency of the maintenance dose are largely variable. In the case of pollen (SLIT), the complexity increases, since preseasonal, coseasonal and pre-coseasonal regimens can be used. The administration regimens are of relevance from a practical point of view, but can also have economic implications. We review herein the available literature (randomized double blind controlled studies) on pollen SLIT, in order to derive experimentally-supported suggestions about the regimens of administration that should be preferred. [source]


    Immunologic characterization of isoforms of Car b 1 and Que a 1, the major hornbeam and oak pollen allergens

    ALLERGY, Issue 3 2009
    M. Wallner
    Background:, Birch pollen allergy is one of the most common causes of spring pollinosis often associated with hypersensitivity reactions to pollen of other Fagales species. Yet, only the major disease eliciting allergens of alder and hazel have been fully characterized. Therefore, the aim of this study was to perform cloning, expression and immunologic characterization of the Bet v 1 homologues from oak (Que a 1) and hornbeam (Car b 1). Methods:, The isoform pattern of Car b 1 and Que a 1 was analyzed by proteomics using 2D gel electrophoresis and LC ESI-QTOF MS. Isoallergens showing high IgE-binding were cloned and expressed in Escherichia coli. IgE-binding activity of the recombinant proteins was determined by enzyme-linked immunosorbent assay (ELISA) and basophil mediator release assays using serum samples from patients mainly exposed either to oak and hornbeam or to birch pollen. Cross-reactivity of the allergens was further investigated at the T-cell level. Results:, Dominant isoforms of Car b 1 and Que a 1, identified by mass spectrometry, showed different IgE-binding properties when testing Fagales pollen-allergic patients living in birch-free areas as compared to birch-sensitized individuals. Conclusion:, Tree pollen-allergic patients who are primarily exposed to Fagales pollen other than birch reacted stronger with rCar b 1 and rQue a 1 than with rBet v 1, as determined by inhibition ELISA and basophil mediator release assays. Thus, rCar b 1 and rQue a 1 allergens should be considered for improving molecule-based diagnosis and therapy of tree pollen allergies manifesting in birch-free areas. [source]


    The safety of sublingual immunotherapy with one or multiple pollen allergens in children

    ALLERGY, Issue 12 2008
    F. Agostinis
    Background:, Since the majority of allergic patients are polysensitized, it is often necessary to prescribe immunotherapy with multiple allergens. It is crucial to know if the administration of multiple allergens with sublingual immunotherapy (SLIT) increases the risk of side-effects in children. Methods:, Consecutive children with respiratory allergy because of pollens, receiving SLIT for multiple or single allergens were followed-up in a postmarketing survey. Inclusion criteria were those for prescribing SLIT according to guidelines. Parents recorded in a diary card the side-effects (eye symptoms, rhinitis/ear itching, asthma, oral itching/swelling, nausea, vomiting, abdominal pain, diarrhoea, urticaria, angioedema and anaphylaxis). The side-effects were graded as mild, moderate and severe. Results:, Four hundred and thirty-three children (285 male, age range 3,18 years) receiving SLIT were surveyed. Of them, 179 received a single extract, and 254 multiple allergens. The total number of doses given was 40 169 (17 143 with single allergen). Overall, 178 episodes were reported. Of them, 76 occurred with the single allergen (42.46% patients, 4.43/1000 doses) and 102 (40.3% patients, 4.42/1000 doses) with multiple allergens (P = NS). 165 episodes (92.5%) were mild and self-resolving and were equally distributed in the two groups. In 13 cases, the events were judged of moderate severity and medical advice was required. Three patients discontinued SLIT, despite the local side-effects being mild. No emergency treatment was required at all. Conclusion:, The use of multiple allergens for SLIT does not increase the rate of side-effects in children. [source]


    Symptoms to pollen and fruits early in life and allergic disease at 4 years of age

    ALLERGY, Issue 11 2008
    X.-M. Mai
    Background:, The predictive value of reported early symptoms to pollen or fruits on later allergic disease is unclear. Our aim is to evaluate if symptoms to pollen and/or to fruits early in life are associated with allergic disease and sensitization to pollen at 4 years. Methods:, The study included 3619 children from the Barn (Children), Allergy, Milieu, Stockholm, Epidemiology project (BAMSE) birth cohort. Reported symptoms of wheeze, sneeze or rash to birch, grass or weed, symptoms (vomiting, diarrhea, rash, facial edema, sneeze, or wheeze) to fruits including tree-nuts at 1 or 2 years of age, and definitions of asthma, rhinitis and eczema at 4 years were derived from questionnaire data. Sensitization to pollen allergens was defined as allergen-specific IgE-antibodies to any pollen (birch/timothy/mugwort) ,0.35 kUA/l. Results:, At 1 or 2 years of age, 6% of the children were reported to have pollen-related symptoms, 6% had symptoms to fruits, and 1.4% to both pollen and fruits. Children with symptoms to both pollen and fruits at 1 or 2 years of age had an increased risk for sensitization to any pollen allergen at age 4 (ORadj = 4.4, 95% CI = 2.1,9.2). This group of children also had a substantially elevated risk for developing any allergic disease (asthma, rhinitis, or eczema) at 4 years irrespective of sensitization to pollen (ORadj = 8.6, 95% CI = 4.5,16.4). Conclusions:, The prevalence of reported symptoms to pollen and fruits is very low in early childhood. However, children with early symptoms to both pollen and fruits appear to have a markedly elevated risk for allergic disease. [source]


    Omalizumab (Xolair) in children with seasonal allergic rhinitis: Leukotriene release as a potential in vitro parameter to monitor therapeutic effects

    PEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 6 2007
    Matthias Volkmar Kopp
    To investigate the effect of omalizumab, a humanized monoclonal antibody, in addition to specific immunotherapy (SIT) on in vitro sulfidoleukotriene release (SLT) (A) before, (B) directly after, and (C) 1 yr after treatment with omalizumab. Children and adolescents (6.3,17.6 yr) with sensitization to birch and grass pollens and suffering from seasonal allergic rhinitis were included in a Phase III, placebo-controlled, multicenter clinical study. Within the four-arm study, patients were randomly chosen to receive SIT for either birch or grass pollen and either subcutaneous omalizumab or placebo for 24 wk during the pollen season. Thereafter, omalizumab or placebo treatment ended, but SIT therapy continued. Blood samples were collected from 92 (A, B) and 78 children (C), respectively. Leukocytes were isolated and stimulated with grass and birch pollen allergens. In the supernatants, SLT (LTC4, LTD4, LTE4) were measured using ELISA [cellular allergen stimulation test, DPC-Biermann, Germany]. At the end of treatment the combination of omalizumab + SIT-grass [median SLT-release: 2125 (before) and 416 ng/ml (after omalizumab treatment); p < 0.001] as well as omalizumab + SIT-birch [1404 and 207 ng/ml; p < 0.001] resulted in significantly lower SLT release after stimulation with the corresponding allergen compared to placebo + SIT-grass [2231 and 2490 ng/ml] or placebo + SIT-birch [1324 and 2489 ng/ml]. One year after omalizumab or placebo treatment, there was no significant difference in SLT release between the 4 groups (omalizumab + SIT-grass: 2855; SIT-grass + placebo: 2543; omalizumab + SIT-birch: 2417; SIT-birch + placebo: 2573 ng/ml). These results strongly suggest that the observed effects of decreased SLT release after omalizumab treatment were attributable to the treatment with omalizumab, rather than to SIT therapy. [source]


    Heterogeneity of commercial timothy grass pollen extracts

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 8 2008
    M. Focke
    Summary Background The diagnosis and specific immunotherapy of allergy is currently performed with allergen extracts prepared from natural allergen sources. Objective To analyse commercial timothy grass pollen allergen extracts used for in vivo diagnosis regarding their qualitative and quantitative allergen composition and in vivo biological activity. Methods Antibodies specific for eight timothy grass pollen allergens (Phl p 1, Phl p 2, Phl p 4, Phl p 5, Phl p 6, Phl p 7, Phl p 12, Phl p 13) were used to detect these allergens in timothy grass pollen extracts from four manufacturers by immunoblotting. ELISA assays were developed and used to quantify the three major allergens (Phl p 1, Phl p 2, Phl p 5) in the extracts. The magnitude of skin responses to the four extracts was studied by skin prick testing in 10 grass pollen-allergic patients. Results The allergen extracts showed broad variations in protein compositions and amounts (24.1,197.7 ,g/mL extract). Several allergens could not be detected in certain extracts or appeared degraded. A considerable variability regarding the contents of major allergens was found (Phl p 1: 32,384 ng/mL; Phl p 2: 1128,6530 ng/mL, Phl p 5: 40,793 ng/mL). Heterogeneous skin test results were obtained with the extracts in grass pollen-allergic patients. Conclusions Timothy grass pollen extracts from different manufacturers exhibit a considerable heterogeneity regarding the presence of individual allergens and hence yield varying in vivo test results. Problems related to the use of natural grass pollen allergen extracts may be circumvented by using defined recombinant grass pollen allergens. [source]


    Characterization of the T cell response to the major hazelnut allergen, Cor a 1.04: evidence for a relevant T cell epitope not cross-reactive with homologous pollen allergens

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2005
    B. Bohle
    Summary Background IgE antibodies specific for the major birch-pollen allergen, Bet v 1, cross-react with homologous allergens in particular foods, e.g. apples, carrots and hazelnuts. In a high number of tree pollen-allergic individuals, this cross-reactivity causes clinical symptoms, commonly known as the ,birch-fruit-syndrome'. Objective To characterize the T cell response to the Bet v 1-related major allergen in hazelnuts, Cor a 1.04, and its cellular cross-reactivity with Bet v 1 and the homologous hazel pollen allergen, Cor a 1. Methods Using recombinant Cor a 1.04, T cell lines (TCL) and T cell clones (TCC) were established from peripheral blood mononuclear cells of tree pollen-allergic patients with associated food allergy. T cell epitopes were determined using overlapping synthetic peptides in Cor a 1.04-reactive TCL and TCC. In parallel, reactivity to Bet v 1 and Cor a 1 was tested. Results In total, 20 distinct T cell epitopes on the hazelnut allergen were identified. Several Cor a 1.04-specific TCL and TCC reacted with pollen allergens albeit less pronounced than with the hazelnut allergen. Several Cor a 1.04-specific TCC did not react with pollen allergens. Interestingly, these clones were found to react with the Bet v 1-related major allergen in carrots, Dau c 1. The cellular cross-reactivity between both food allergens could be associated with the most frequently recognized T cell epitope of Cor a 1.04, Cor a 1.04142,153. Conclusions The major hazelnut allergen cross-reacts with the major allergens of birch and hazel pollen but apparently contains a relevant T cell epitope not shared with pollen allergens. Our finding may have important implications for the specific immunotherapy of tree pollen-allergic patients suffering from concomitant hazelnut allergy. [source]


    The novel use of the human nasal epithelial cell line RPMI 2650 as an in vitro model to study the influence of allergens and cytokines on transforming growth factor-, gene expression and protein release

    CLINICAL & EXPERIMENTAL ALLERGY, Issue 6 2005
    R. J. Salib
    Summary Background The epithelial accumulation of mast cells is a feature of allergic rhinitis and this has been linked to the expression of the known mast cell chemoattractant transforming growth factor-, (TGF-,) at this site. Little is known concerning the regulation of TGF-, gene expression or protein release by nasal epithelial cells. To address this we have utilized the RPMI 2650 human nasal epithelial cell line, which has some features that closely resemble normal nasal epithelium and has been reported to secrete a TGF-,-like molecule. Objectives To investigate the regulation of TGF-, gene expression and protein secretion in RPMI 2650 nasal epithelial cells following exposure to allergens (house dust mite (HDM) and grass pollen) and mast cell associated T-helper type 2 (Th2) cytokines (IL-4, IL-13, and TNF-,). Methods Light and scanning electron microscopy was used to evaluate the morphology of RPMI 2650 cells in culture, enzyme-linked immunosorbent assay was used to investigate their TGF-, secretory capacity and the identification of the TGF-, isotype(s) involved, flow cytometry was used to demonstrate the presence of TGF-, receptors on the RPMI 2650 cells, and the quantitative real-time TaqMan PCR was used to measure TGF-, gene expression. Results TGF-,2 was identified as the main isotype secreted by the RPMI 2650 cells. HDM allergens and TNF-, increased both TGF-, gene expression and protein release from these cells, whereas grass pollen, IL-4, and IL-13 were without effect. Conclusions The RPMI 2650 nasal epithelial cell line represents a valid in vitro model to evaluate the regulation of TGF-, biology. In this system HDM allergens have stimulatory activity that is fundamentally different from that of grass pollen allergens, and the Th2 cytokines IL-4 and IL-13 are without effect. The ability of TNF-, to up-regulate both TGF-, gene expression and protein release indicates that mast cell,epithelial interactions concerning TGF-, are bi-directional and this may be fundamental to epithelial immunoregulation. The availability of a model system, such as the RPMI 2650 cells, will enable the early evaluation of future novel and targeted interventions directed toward the aberrant responses of upper airway structural cells. [source]