Publications by authors named "Heimo Breiteneder"

125 Publications

Allergens and their associated small molecule ligands-their dual role in sensitization.

Allergy 2021 Apr 18. Epub 2021 Apr 18.

Division of Medical Biotechnology, Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

Many allergens feature hydrophobic cavities that allow the binding of primarily hydrophobic small-molecule ligands. Ligand-binding specificities can be strict or promiscuous. Serum albumins from mammals and birds can assume multiple conformations that facilitate the binding of a broad spectrum of compounds. Pollen and plant food allergens of the family 10 of pathogenesis-related proteins bind a variety of small molecules such as glycosylated flavonoid derivatives, flavonoids, cytokinins, and steroids in vitro. However, their natural ligand binding was reported to be highly specific. Insect and mammalian lipocalins transport odorants, pheromones, catecholamines, and fatty acids with a similar level of specificity, while the food allergen β-lactoglobulin from cow's milk is notably more promiscuous. Non-specific lipid transfer proteins from pollen and plant foods bind a wide variety of lipids, from phospholipids to fatty acids, as well as sterols and prostaglandin B2, aided by the high plasticity and flexibility displayed by their lipid-binding cavities. Ligands increase the stability of allergens to thermal and proteolyticdegradation. They can also act as immunomodulatory agents that favor a Th2 polarization. In summary, ligand-binding allergens expose the immune system to a variety of biologically active compounds whose impact on the sensitization process has not been well studied thus far.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14861DOI Listing
April 2021

Vaccines and Allergic reactions: the past, the current COVID-19 pandemic, and future perspectives.

Allergy 2021 Apr 2. Epub 2021 Apr 2.

Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.

Vaccines are essential public health tools with a favorable safety profile and prophylactic effectiveness that have historically played significant roles in reducing infectious disease burden in populations, when the majority of individuals are vaccinated. The COVID-19 vaccines are expected to have similar positive impacts on health across the globe. While serious allergic reactions to vaccines are rare, their underlying mechanisms and implications for clinical management should be considered to provide individuals with the safest care possible. In this review, we provide an overview of different types of allergic adverse reactions that can potentially occur aftervaccination and individual vaccine components capable of causing the allergic adverse reactions. We present the incidence of allergic adverse reactions during clinical studies and through post-authorization and post-marketing surveillance and provide plausible causes of these reactions based on potential allergenic components present in several common vaccines. Additionally, we review implications for individual diagnosis and management and vaccine manufacturing overall. Finally, we suggest areas for future research.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14840DOI Listing
April 2021

Expression of chondroitin sulfate proteoglycan 4 (CSPG4) in melanoma cells is downregulated upon inhibition of BRAF.

Oncol Rep 2021 04 2;45(4). Epub 2021 Mar 2.

Department of Dermatology, University Hospital St. Poelten, Karl Landsteiner University of Health Sciences, 3100 St. Poelten, Austria.

Chondroitin sulfate proteoglycan 4 (CSPG4) is a multifunctional transmembrane proteoglycan involved in spreading, migration and invasion of melanoma. In addition to the activating BRAF V600E mutation, CSPG4 was shown to promote MAPK signaling by mediating the growth‑factor induced activation of receptor tyrosine kinases. However, it remains elusive which factors regulate CSPG4 expression. Therefore, the aim of the present study was to examine whether BRAF and MEK inhibitors have an effect on the expression of CSPG4. We exposed a panel of BRAF‑mutant CSPG4‑positive or ‑negative melanoma cell lines to BRAF and MEK inhibitors. Protein levels of CSPG4 were analyzed by flow cytometry (FACS), immunofluorescence microscopy (IF), and western blotting. mRNA levels were determined by quantitative PCR (qPCR). The prolonged exposure of cells to BRAF and MEK inhibitors resulted in markedly reduced levels of the CSPG4 protein in permanent resistant melanoma cells as well as decreased levels of its mRNA. We did not observe increasing levels of CSPG4 shedding into the culture supernatants. In addition, patient‑derived matched tumor samples following therapy with kinase inhibitors showed decreased numbers of CSPG4‑positive cells as compared to pre‑therapy tumor samples. Our results indicate that BRAF and MEK inhibition downregulates CSPG4 expression until the cells have developed permanent resistance. Our findings provide the basis for further investigation of the role of CSPG4 in the development of drug‑resistance in melanoma cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3892/or.2021.7965DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7876987PMC
April 2021

Basophil activation test shows high accuracy in the diagnosis of peanut and tree nut allergy: The Markers of Nut Allergy Study.

Allergy 2020 Dec 9. Epub 2020 Dec 9.

Translational Medicine, Research Institute, Hospital for Sick Children, Toronto, ON, Canada.

Background: Peanut and tree nut allergies are the most important causes of anaphylaxis. Co-reactivity to more than one nut is frequent, and co-sensitization in the absence of clinical data is often obtained. Confirmatory oral food challenges (OFCs) are inconsistently performed.

Objective: To investigate the utility of the basophil activation test (BAT) in diagnosing peanut and tree nut allergies.

Methods: The Markers Of Nut Allergy Study (MONAS) prospectively enrolled patients aged 0.5-17 years with confirmed peanut and/or tree nut (almond, cashew, hazelnut, pistachio, walnut) allergy or sensitization from Canadian (n = 150) and Austrian (n = 50) tertiary pediatric centers. BAT using %CD63 basophils (SSClow/CCR3pos) as outcome was performed with whole blood samples stimulated with allergen extracts of each nut (0.001-1000 ng/mL protein). BAT results were assessed against confirmed allergic status in a blinded fashion to develop a generalizable statistical model for comparison to extract and marker allergen-specific IgE.

Results: A mixed effect model integrating BAT results for 10 and 100 ng/mL of peanut and individual tree nut extracts was optimal. The area under the ROC curve (AUROC) was 0.98 for peanut, 0.97 for cashew, 0.92 for hazelnut, 0.95 for pistachio, and 0.97 for walnut. The BAT outperformed sIgE testing for peanut or hazelnut and was comparable for walnut (AUROC 0.95, 0.94, 0.92) in a sub-analysis in sensitized patients undergoing OFC.

Conclusions: Basophil activation test can predict allergic clinical status to peanut and tree nuts in multi-nut-sensitized children and may reduce the need for high-risk OFCs in patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14695DOI Listing
December 2020

Identification of Pru du 6 as a potential marker allergen for almond allergy.

Allergy 2021 May 21;76(5):1463-1472. Epub 2020 Oct 21.

Center of Pathophysiology, Infectiology and Immunology, Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

Background: Oral food challenges have demonstrated that diagnosis of almond allergy based on extract-sIgE tests displays low specificity. Molecular allergy diagnosis is expected to improve accuracy, but its value in diagnosing almond allergy remains unknown. The aim of this study was to identify relevant almond allergens and examine their ability to improve almond allergy diagnosis.

Methods: IgE-reactive proteins were purified from almond kernels. IgE binding to almond extract and the allergens was analyzed by quantitative ELISA using sera from 18 subjects with a proven almond allergy. The control group consisted of sera from 18 subjects allergic to peanut and/or tree nuts but tolerant to almond.

Results: Three IgE-binding proteins were identified: legumin (Pru du 6), alpha-hairpinin (Pru du 8), and mandelonitrile lyase (Pru du 10). Positive IgE (≥0.35 kU/L) to almond extract showed 94% sensitivity but only 33% specificity. IgE to Pru du 6 maintained high sensitivity (83%) and provided superior specificity (78%). Sera from almond-allergic subjects had significantly higher IgE levels to almond extract (P < .0001) and Pru du 6 (P < .0001) than sera from tolerant donors. Sensitization to Pru du 6 was highly specific for almond allergy, while frequencies of sensitization to legumins from peanut, walnut, hazelnut, and cashew were similar in both groups. IgE to Pru du 8 and Pru du 10 was less sensitive (41% and 67%), but showed specificities of 100% and 61%.

Conclusion: The use of almond allergens markedly increases the diagnostic specificity compared to the extract. Pru du 6 is a potential new molecular marker for almond allergy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14613DOI Listing
May 2021

Biomarkers for diagnosis and prediction of therapy responses in allergic diseases and asthma.

Allergy 2020 12 30;75(12):3039-3068. Epub 2020 Sep 30.

Swiss Institute of Allergy and Asthma Research (SIAF), University Zurich, Davos, Switzerland.

Modern health care requires a proactive and individualized response to diseases, combining precision diagnosis and personalized treatment. Accordingly, the approach to patients with allergic diseases encompasses novel developments in the area of personalized medicine, disease phenotyping and endotyping, and the development and application of reliable biomarkers. A detailed clinical history and physical examination followed by the detection of IgE immunoreactivity against specific allergens still represents the state of the art. However, nowadays, further emphasis focuses on the optimization of diagnostic and therapeutic standards and a large number of studies have been investigating the biomarkers of allergic diseases, including asthma, atopic dermatitis, allergic rhinitis, food allergy, urticaria and anaphylaxis. Various biomarkers have been developed by omics technologies, some of which lead to a better classification of distinct phenotypes or endotypes. The introduction of biologicals to clinical practice increases the need for biomarkers for patient selection, prediction of outcomes and monitoring, to allow for an adequate choice of the duration of these costly and long-lasting therapies. Escalating healthcare costs together with questions about the efficacy of the current management of allergic diseases require further development of a biomarker-driven approach. Here, we review biomarkers in diagnosis and treatment of asthma, atopic dermatitis, allergic rhinitis, viral infections, chronic rhinosinusitis, food allergy, drug hypersensitivity and allergen immunotherapy with a special emphasis on specific IgE, the microbiome and the epithelial barrier. In addition, EAACI guidelines on biologicals are discussed within the perspective of biomarkers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14582DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7756301PMC
December 2020

Advances and novel developments in molecular allergology.

Allergy 2020 12 22;75(12):3027-3038. Epub 2020 Sep 22.

Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

The continuous search for new allergens and the design of allergen derivatives improves the understanding of their allergenicity and aids the design of novel diagnostic and immunotherapy approaches. This article discusses the recent developments in allergen and epitope discovery, allergy diagnostics and immunotherapy. Structural information is crucial for the elucidation of cross-reactivity of marker allergens such as the walnut Jug r 6 or that of nonhomologous allergens, as shown for the peanut allergens Ara h 1 and 2. High-throughput sequencing, liposomal nanoallergen display, bead-based assays, and protein chimeras have been used in epitope discovery. The binding of natural ligands by the birch pollen allergen Bet v 1 or the mold allergen Alt a 1 increased the stability of these allergens, which is directly linked to their allergenicity. We also report recent findings on the use of component-resolved approaches, basophil activation test, and novel technologies for improvement of diagnostics. New strategies in allergen-specific immunotherapy have also emerged, such as the use of virus-like particles, biologics or novel adjuvants. The identification of dectin-1 as a key player in allergy to tropomyosins and the formyl peptide receptor 3 in allergy to lipocalins are outstanding examples of research into the mechanism of allergic sensitization.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14579DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7756543PMC
December 2020

Expanding the allergen repertoire of salmon and catfish.

Allergy 2021 May 15;76(5):1443-1453. Epub 2020 Oct 15.

Molecular Allergy Research Laboratory, College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Qld, Australia.

Background: Diagnostic tests for fish allergy are hampered by the large number of under-investigated fish species. Four salmon allergens are well-characterized and registered with the WHO/IUIS while no catfish allergens have been described so far. In 2008, freshwater-cultured catfish production surpassed that of salmon, the globally most-cultured marine species. We aimed to identify, quantify, and compare all IgE-binding proteins in salmon and catfish.

Methods: Seventy-seven pediatric patients with clinically confirmed fish allergy underwent skin prick tests to salmon and catfish. The allergen repertoire of raw and heated protein extracts was evaluated by immunoblotting using five allergen-specific antibodies and patients' serum followed by mass spectrometric analyses.

Results: Raw and heated extracts from catfish displayed a higher frequency of IgE-binding compared to those from salmon (77% vs 70% and 64% vs 53%, respectively). The major fish allergen parvalbumin demonstrated the highest IgE-binding capacity (10%-49%), followed by triosephosphate isomerase (TPI; 19%-34%) in raw and tropomyosin (6%-32%) in heated extracts. Six previously unidentified fish allergens, including TPI, were registered with the WHO/IUIS. Creatine kinase from salmon and catfish was detected by IgE from 14% and 10% of patients, respectively. Catfish L-lactate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase, and glucose-6-phosphate isomerase showed IgE-binding for 6%-13% of patients. In salmon, these proteins could not be separated successfully.

Conclusions: We detail the allergen repertoire of two highly farmed fish species. IgE-binding to fish tropomyosins and TPIs was demonstrated for the first time in a large patient cohort. Tropomyosins, in addition to parvalbumins, should be considered for urgently needed improved fish allergy diagnostics.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14574DOI Listing
May 2021

A compendium answering 150 questions on COVID-19 and SARS-CoV-2.

Allergy 2020 10 20;75(10):2503-2541. Epub 2020 Jul 20.

Department of Immunology and Pathology, Monash University, Melbourne, Vic., Australia.

In December 2019, China reported the first cases of the coronavirus disease 2019 (COVID-19). This disease, caused by the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2), has developed into a pandemic. To date, it has resulted in ~9 million confirmed cases and caused almost 500 000 related deaths worldwide. Unequivocally, the COVID-19 pandemic is the gravest health and socioeconomic crisis of our time. In this context, numerous questions have emerged in demand of basic scientific information and evidence-based medical advice on SARS-CoV-2 and COVID-19. Although the majority of the patients show a very mild, self-limiting viral respiratory disease, many clinical manifestations in severe patients are unique to COVID-19, such as severe lymphopenia and eosinopenia, extensive pneumonia, a "cytokine storm" leading to acute respiratory distress syndrome, endothelitis, thromboembolic complications, and multiorgan failure. The epidemiologic features of COVID-19 are distinctive and have changed throughout the pandemic. Vaccine and drug development studies and clinical trials are rapidly growing at an unprecedented speed. However, basic and clinical research on COVID-19-related topics should be based on more coordinated high-quality studies. This paper answers pressing questions, formulated by young clinicians and scientists, on SARS-CoV-2, COVID-19, and allergy, focusing on the following topics: virology, immunology, diagnosis, management of patients with allergic disease and asthma, treatment, clinical trials, drug discovery, vaccine development, and epidemiology. A total of 150 questions were answered by experts in the field providing a comprehensive and practical overview of COVID-19 and allergic disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14449DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7323196PMC
October 2020

Increased antiviral response in circulating lymphocytes from hypogammaglobulinemia patients.

Allergy 2020 12 16;75(12):3147-3158. Epub 2020 Jul 16.

Swiss Institute of Allergy and Asthma Research (SIAF), University of Zurich, Davos, Switzerland.

Background: B cells play a crucial role during rhinovirus (RV) infections by production of virus-neutralizing antibodies. A main feature of common variable immunodeficiency (CVID) is hypogammaglobulinemia (HG). HG patients have severely reduced levels of antibody-producing B cells and suffer from prolonged virus infections. Here, we addressed whether antiviral response of peripheral blood lymphocytes differs between HG patients and healthy individuals during natural RV infection.

Methods: Using fluorescence-activated cell sorting, B-cell subsets were analyzed. Simultaneously, CD19 + B cells, CD14 + monocytes, and CD3 + T cells were sorted from frozen peripheral blood mononuclear cells from 11 RV-infected hypogammaglobulinemia patients, 7 RV-infected control subjects, and 14 noninfected control subjects. Real-time PCR was used to study expression of antiviral genes. A pan-RV PCR was used to detect RV genome in all samples.

Results: In HG patients, total B-cell numbers, as well as IgA + and IgG + switched memory B cells, were reduced while naïve B cells and T cells were increased. STAT1 expression was increased in HG patients compared to controls in all lymphocyte subsets analyzed. The expression of antiviral genes IFITM1 and MX1 correlated with STAT1 expression in B cells and monocytes. RV RNA was found in 88.9% of monocytes from infected HG patients, 85.7% of monocytes from infected controls, and 7.1% of monocytes from uninfected controls.

Conclusions: We demonstrate an increased antiviral response in B cells and monocytes in HG patients and their correlation with STAT1 expression. Monocytes of infected HG patients and infected non-HG controls carry RV RNA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14445DOI Listing
December 2020

COVID-19 pandemic: Practical considerations on the organization of an allergy clinic-An EAACI/ARIA Position Paper.

Allergy 2021 03;76(3):648-676

Institute of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.

Background: The coronavirus disease 2019 (COVID-19) has evolved into a pandemic infectious disease transmitted by the severe acute respiratory syndrome coronavirus (SARS-CoV-2). Allergists and other healthcare providers (HCPs) in the field of allergies and associated airway diseases are on the front line, taking care of patients potentially infected with SARS-CoV-2. Hence, strategies and practices to minimize risks of infection for both HCPs and treated patients have to be developed and followed by allergy clinics.

Method: The scientific information on COVID-19 was analysed by a literature search in MEDLINE, PubMed, the National and International Guidelines from the European Academy of Allergy and Clinical Immunology (EAACI), the Cochrane Library, and the internet.

Results: Based on the diagnostic and treatment standards developed by EAACI, on international information regarding COVID-19, on guidelines of the World Health Organization (WHO) and other international organizations, and on previous experience, a panel of experts including clinicians, psychologists, IT experts, and basic scientists along with EAACI and the "Allergic Rhinitis and its Impact on Asthma (ARIA)" initiative have developed recommendations for the optimal management of allergy clinics during the current COVID-19 pandemic. These recommendations are grouped into nine sections on different relevant aspects for the care of patients with allergies.

Conclusions: This international Position Paper provides recommendations on operational plans and procedures to maintain high standards in the daily clinical care of allergic patients while ensuring the necessary safety measures in the current COVID-19 pandemic.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14453DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7323448PMC
March 2021

Collagen-An Important Fish Allergen for Improved Diagnosis.

J Allergy Clin Immunol Pract 2020 10 7;8(9):3084-3092.e10. Epub 2020 May 7.

College of Public Health, Medical and Veterinary Sciences, Australian Institute of Tropical Health and Medicine, Molecular Allergy Research Laboratory, James Cook University, Townsville, QLD, Australia; Centre for Food and Allergy Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia. Electronic address:

Background: Fish collagen is widely used in medicine, cosmetics, and the food industry. However, its clinical relevance as an allergen is not fully appreciated. This is likely due to collagen insolubility in neutral aqueous solutions, leading to low abundance in commercially available in vitro and skin prick tests for fish allergy.

Objective: To investigate the relevance of fish collagen as an allergen in a large patient population (n = 101).

Methods: Acid-soluble collagen type I was extracted from muscle and skin of Atlantic salmon, barramundi, and yellowfin tuna. IgE binding to collagen was analyzed by ELISA for 101 fish-allergic patients. Collagen-sensitized patients' sera were tested for IgE binding to parvalbumin from the same fish species. IgE cross-linking was analyzed by rat basophil leukemia assay and basophil activation test. Protein identities were confirmed by mass spectrometry.

Results: Purified fish collagen contained type I α1 and α2 chains and their multimers. Twenty-one of 101 patients (21%) were sensitized to collagen. Eight collagen-sensitized patients demonstrated absence of parvalbumin-specific IgE to some fish species. Collagen induced functional IgE cross-linking, as shown by rat basophil leukemia assay performed using 6 patients' sera, and basophil activation test using fresh blood from 1 patient. Collagen type I α chains from barramundi and Atlantic salmon were registered at www.allergen.org as Lat c 6 and Sal s 6, respectively.

Conclusions: IgE sensitization and IgE cross-linking capacity of fish collagen were demonstrated in fish-allergic patients. Inclusion of relevant collagen allergens in routine diagnosis is indicated to improve the capacity to accurately diagnose fish allergy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaip.2020.04.063DOI Listing
October 2020

Allergen-specific IgE levels and the ability of IgE-allergen complexes to cross-link determine the extent of CD23-mediated T-cell activation.

J Allergy Clin Immunol 2020 03 24;145(3):958-967.e5. Epub 2019 Nov 24.

Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria.

Background: CD23 mediates IgE-facilitated allergen presentation and subsequent allergen-specific T-cell activation in allergic patients.

Objective: We sought to investigate key factors regulating IgE-facilitated allergen presentation through CD23 and subsequent T-cell activation.

Methods: To study T-cell activation by free allergens and different types of IgE-Bet v 1 complexes, we used a molecular model based on monoclonal human Bet v 1-specific IgE, monomeric and oligomeric Bet v 1 allergen, an MHC-matched CD23-expressing B-cell line, and a T-cell line expressing a human Bet v 1-specific T-cell receptor. The ability to cross-link Fcε receptors of complexes consisting of either IgE and monomeric Bet v 1 or IgE and oligomeric Bet v 1 was studied in human FcεRI-expressing basophils. T-cell proliferation by monomeric or oligomeric Bet v 1, which cross-links Fcε receptors to a different extent, was studied in allergic patients' PBMCs with and without CD23-expressing B cells.

Results: In our model non-cross-linking IgE-Bet v 1 monomer complexes, as well as cross-linking IgE-Bet v 1 oligomer complexes, induced T-cell activation, which was dependent on the concentration of specific IgE. However, T-cell activation by cross-linking IgE-Bet v 1 oligomer complexes was approximately 125-fold more efficient. Relevant T-cell proliferation occurred in allergic patients' PBMCs only in the presence of B cells, and its magnitude depended on the ability of IgE-Bet v 1 complexes to cross-link CD23.

Conclusion: The extent of CD23-mediated T-cell activation depends on the concentration of allergen-specific IgE and the cross-linking ability of IgE-allergen complexes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaci.2019.11.019DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7104374PMC
March 2020

Cross-reactivities of non-homologous allergens.

Allergy 2020 05;75(5):1019-1022

Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14120DOI Listing
May 2020

Legends of allergy and immunology: Clemens von Pirquet.

Allergy 2020 05 6;75(5):1276-1277. Epub 2019 Dec 6.

Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.14115DOI Listing
May 2020

Development of a novel Ara h 2 hypoallergen with no IgE binding or anaphylactogenic activity.

J Allergy Clin Immunol 2020 01 13;145(1):229-238. Epub 2019 Sep 13.

Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.

Background: To date, no safe allergen-specific immunotherapy for patients with peanut allergy is available. Previous trials were associated with severe side effects.

Objective: We sought to determine the relative importance of conformational and linear IgE-binding epitopes of the major peanut allergen Ara h 2 and to produce a hypoallergenic variant with abolished anaphylactogenic activity.

Methods: Wild-type Ara h 2 and a mutant lacking the loops containing linear IgE epitopes were produced in insect cells. Conformational IgE epitopes were removed by unfolding these proteins through reduction and alkylation. IgE binding was tested by means of ELISA with sera from 48 Ara h 2-sensitized patients with peanut allergy. Basophil activation and T-cell proliferation were tested with blood samples from selected patients. Anaphylactogenic potency was tested by using intraperitoneal challenge of mice sensitized intragastrically to peanut extract.

Results: Patients' IgE recognized conformational and linear epitopes in a patient-specific manner. The unfolded mutant lacking both types of epitopes displayed significantly lower IgE binding (median ELISA OD, 0.03; interquartile range, 0.01-0.06) than natural Ara h 2 (median ELISA OD, 0.99; interquartile range, 0.90-1.03; P < .01). Basophil activation by unfolded mutant Ara h 2 was low (median area under the curve, 72 vs 138 for native wild-type Ara h 2; P < .05), but its ability to induce T-cell proliferation was retained. Unfolded mutants without conformational epitopes did not induce anaphylaxis in peanut-sensitized mice.

Conclusions: By removing conformational and linear IgE epitopes, a hypoallergenic Ara h 2 mutant with abolished IgE binding and anaphylactogenic potency but retained T-cell activation was generated.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaci.2019.08.036DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7100897PMC
January 2020

Fish-derived low molecular weight components modify bronchial epithelial barrier properties and release of pro-inflammatory cytokines.

Mol Immunol 2019 08 15;112:140-150. Epub 2019 May 15.

Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria. Electronic address:

The prevalence of fish allergy among fish-processing workers is higher than in the general population, possibly due to sensitization via inhalation and higher exposure. However, the response of the bronchial epithelium to fish allergens has never been explored. Parvalbumins (PVs) from bony fish are major sensitizers in fish allergy, while cartilaginous fish and their PVs are considered less allergenic. Increasing evidence demonstrates that components other than proteins from the allergen source, such as low molecular weight components smaller than 3 kDa (LMC) from pollen, may act as adjuvants during allergic sensitization. We investigated the response of bronchial epithelial cells to PVs and to LMC from Atlantic cod, a bony fish, and gummy shark, a cartilaginous fish. Polarized monolayers of the bronchial epithelial cell line 16HBE14o- were stimulated apically with fish PVs and/-or the corresponding fish LMC. Barrier integrity, transport of PVs across the monolayers and release of mediators were monitored. Intact PVs from both the bony and the cartilaginous fish were rapidly internalized by the cells and transported to the basolateral side of the monolayers. The PVs did not disrupt the epithelial barrier integrity nor did they modify the release of proinflammatory cytokines. In contrast, LMC from both fish species modified the physical and immunological properties of the epithelial barrier and the responses differed between bony and cartilaginous fish. While the barrier integrity was lowered by cod LMC 24 h after cell stimulation, it was increased by up to 2.3-fold by shark LMC. Furthermore, LMC from both fish species increased basolateral and apical release of IL-6 and IL-8, while CCL2 release was increased by cod but not by shark LMC. In summary, our study demonstrated the rapid transport of PVs across the epithelium which may result in their availability to antigen presenting cells required for allergic sensitization. Moreover, different cell responses to LMC derived from bony versus cartilaginous fish were observed, which may play a role in different allergenic potentials of these two fish classes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.molimm.2019.04.029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6997027PMC
August 2019

Future research trends in understanding the mechanisms underlying allergic diseases for improved patient care.

Allergy 2019 12 4;74(12):2293-2311. Epub 2019 Jun 4.

Christine Kühne Center for Allergy Research and Education, Davos, Switzerland.

The specialties of allergy and clinical immunology have entered the era of precision medicine with the stratification of diseases into distinct disease subsets, specific diagnoses, and targeted treatment options, including biologicals and small molecules. This article reviews recent developments in research and patient care and future trends in the discipline. The section on basic mechanisms of allergic diseases summarizes the current status and defines research needs in structural biology, type 2 inflammation, immune tolerance, neuroimmune mechanisms, role of the microbiome and diet, environmental factors, and respiratory viral infections. In the section on diagnostic challenges, clinical trials, precision medicine and immune monitoring of allergic diseases, asthma, allergic and nonallergic rhinitis, and new approaches to the diagnosis and treatment of drug hypersensitivity reactions are discussed in further detail. In the third section, unmet needs and future research areas for the treatment of allergic diseases are highlighted with topics on food allergy, biologics, small molecules, and novel therapeutic concepts in allergen-specific immunotherapy for airway disease. Unknowns and future research needs are discussed at the end of each subsection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.13851DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6973012PMC
December 2019

Allergen databases-A critical evaluation.

Allergy 2019 11;74(11):2057-2060

Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.13841DOI Listing
November 2019

Legends of allergy/immunology: Dietrich Kraft.

Allergy 2019 08 20;74(8):1591-1593. Epub 2019 May 20.

Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.13816DOI Listing
August 2019

Evidence for a Role of TGF-β-Activated Kinase 1 and MAP3K7 Binding Protein 3 in Peanut-Specific T-Cell Responses.

Int Arch Allergy Immunol 2019;179(1):10-16. Epub 2019 Mar 20.

Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria,

Peanut allergy is considered to be the most common cause for food-induced anaphylaxis. Currently, no approved treatment is available. Avoidance is the only measure to prevent anaphylactic reactions to peanuts. T-helper cells are of special importance for the sensitization process and the maintenance of allergic inflammation. Identifying markers of allergen-specific T-cell responses may help to develop novel treatment approaches. Therefore, we aimed to define new T-cell target genes in Ara h 2-specific T cells and to investigate the possibility of using them as biomarkers of peanut allergy in peripheral blood mononuclear cells (PBMCs). We performed whole mRNA array analysis (whole human genome oligo microarray) of in vitro expanded Ara h 2-specific T cells (CFSElowCD3+CD4+) from 5 peanut-allergic (PA) and 5 non-peanut-sensitized individuals. Expression of selected genes as a result of a two-step bioinformatic approach was confirmed in a second cohort by quantitative PCR. TGF-β- activated kinase 1 and MAP3K7 binding protein 3 (TAB3), calcium/calmodulin-dependent protein kinase type IV (CAMK4) and HemK methyltransferase family member 1 (HEMK1) were significantly upregulated in Ara h 2-specific T cells of PA patients. In addition, the expression of these genes was also assessed in unstimulated PBMCs from a cohort (n = 43) of PA, atopic non-PA, and nonatopic controls. Interestingly, in unstimulated PBMCs, TAB3 expression was significantly downregulated in PA patients compared to atopic non-PA individuals. Thus, TAB3 may play a significant role at the level of T-cell activation and may also be a candidate biomarker for PA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000496438DOI Listing
May 2019

The functional biology of peanut allergens and possible links to their allergenicity.

Allergy 2019 05 1;74(5):888-898. Epub 2019 Feb 1.

Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

Peanut is one of the most common food triggers of fatal anaphylaxis worldwide although peanut allergy affects only 1%-2% of the general population. Peanuts are the source of highly potent allergenic proteins. It is emerging that the allergenicity of certain proteins is linked to their biological function. Peanut is an unusual crop in that it flowers aboveground but produces its seed-containing pods underground. This so-called geocarpic fruiting habit exposes pods and seeds during their development to soilborne pathogens and pests. Pest damage can also open routes of entry for opportunistic fungi such as Aspergillus. Although seed proteins have primary functions in nutrient reservoirs, lipid storage bodies, or the cytoskeleton, they have also evolved to act as part of the plant's defense system to enhance fitness and survival of the species. When interacting with pathogens or pests, these proteins modify and damage cells' membranes, interact with immune receptors, and modulate signaling pathways. Moreover, following exposure, the immune system of predisposed individuals reacts to these proteins with the production of specific IgE. This review explores the evolutionary biology of peanut and its seed proteins and highlights possible links between the proteins' biological function and their allergenicity.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.13719DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6563476PMC
May 2019

The WHO/IUIS Allergen Nomenclature.

Allergy 2019 03;74(3):429-431

Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.13693DOI Listing
March 2019

Patients Allergic to Fish Tolerate Ray Based on the Low Allergenicity of Its Parvalbumin.

J Allergy Clin Immunol Pract 2019 02 22;7(2):500-508.e11. Epub 2018 Nov 22.

Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Luxembourg.

Background: Clinical reactions to bony fish species are common in patients with allergy to fish and are caused by parvalbumins of the β-lineage. Cartilaginous fish such as rays and sharks contain mainly α-parvalbumins and their allergenicity is not well understood.

Objective: To investigate the allergenicity of cartilaginous fish and their α-parvalbumins in individuals allergic to bony fish.

Methods: Sensitization to cod, salmon, and ray among patients allergic to cod, salmon, or both (n = 18) was explored by prick-to-prick testing. Clinical reactivity to ray was assessed in 11 patients by food challenges or clinical workup. IgE-binding to β-parvalbumins (cod, carp, salmon, barramundi, tilapia) and α-parvalbumins (ray, shark) was determined by IgE-ELISA. Basophil activation tests and skin prick tests were performed with β-parvalbumins from cod, carp, and salmon and α-parvalbumins from ray and shark.

Results: Tolerance of ray was observed in 10 of 11 patients. Prick-to-prick test reactions to ray were markedly lower than to bony fish (median wheal diameter 2 mm with ray vs 11 mm with cod and salmon). IgE to α-parvalbumins was lower (median, 0.1 kU/L for ray and shark) than to β-parvalbumins (median, ≥1.65 kU/L). Furthermore, α-parvalbumins demonstrated a significantly reduced basophil activation capacity compared with β-parvalbumins (eg, ray vs cod, P < .001; n = 18). Skin prick test further demonstrated lower reactivity to α-parvalbumins compared with β-parvalbumins.

Conclusions: Most patients allergic to bony fish tolerated ray, a cartilaginous fish, because of low allergenicity of its α-parvalbumin. A careful clinical workup and in vitro IgE-testing for cartilaginous fish will improve patient management and may introduce an alternative to bony fish into patients' diet.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaip.2018.11.011DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7060078PMC
February 2019

Peanut allergy-Individual molecules as a key to precision medicine.

Allergy 2019 02;74(2):216-219

WHO/IUIS Allergen Nomenclature Sub-Committee.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.13625DOI Listing
February 2019

Mapping of conformational IgE epitopes of food allergens.

Allergy 2018 11;73(11):2107-2109

Institute of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/all.13592DOI Listing
November 2018

Peanut allergens.

Mol Immunol 2018 08 19;100:58-70. Epub 2018 Apr 19.

Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria. Electronic address:

Peanut allergens have the potential to negatively impact on the health and quality of life of millions of consumers worldwide. The seeds of the peanut plant Arachis hypogaea contain an array of allergens that are able to induce the production of specific IgE antibodies in predisposed individuals. A lot of effort has been focused on obtaining the sequences and structures of these allergens due to the high health risk they represent. At present, 16 proteins present in peanuts are officially recognized as allergens. Research has also focused on their in-depth immunological characterization as well as on the design of modified hypoallergenic derivatives for potential use in clinical studies and the formulation of strategies for immunotherapy. Detailed research protocols are available for the purification of natural allergens as well as their recombinant production in bacterial, yeast, insect, and algal cells. Purified allergen molecules are now routinely used in diagnostic multiplex protein arrays for the detection of the presence of allergen-specific IgE. This review gives an overview on the wealth of knowledge that is available on individual peanut allergens.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.molimm.2018.04.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7060077PMC
August 2018

Recombinant Allergens in Structural Biology, Diagnosis, and Immunotherapy.

Int Arch Allergy Immunol 2017 4;172(4):187-202. Epub 2017 May 4.

Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria.

The years 1988-1995 witnessed the beginning of allergen cloning and the generation of recombinant allergens, which opened up new avenues for the diagnosis and research of human allergic diseases. Most crystal and solution structures of allergens have been obtained using recombinant allergens. Structural information on allergens allows insights into their evolutionary biology, illustrates clinically observed cross-reactivities, and makes the design of hypoallergenic derivatives for allergy vaccines possible. Recombinant allergens are widely used in molecule-based allergy diagnosis such as protein microarrays or suspension arrays. Recombinant technologies have been used to produce well-characterized, noncontaminated vaccine components with known biological activities including a variety of allergen derivatives with reduced IgE reactivity. Such recombinant hypoallergens as well as wild-type recombinant allergens have been used successfully in several immunotherapy trials for more than a decade to treat birch and grass pollen allergy. As a more recent application, the development of antibody repertoires directed against conformational epitopes during immunotherapy has been monitored by recombinant allergen chimeras. Although much progress has been made, the number and quality of recombinant allergens will undoubtedly increase and keep improving our knowledge in basic scientific investigations, diagnosis, and therapy of human allergic diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000464104DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5472216PMC
August 2017

Lactobacillus buchneri S-layer as carrier for an Ara h 2-derived peptide for peanut allergen-specific immunotherapy.

Mol Immunol 2017 05 14;85:81-88. Epub 2017 Feb 14.

Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, 1190 Vienna, Austria.

Peanut allergy is an IgE-mediated severe hypersensitivity disorder. The lack of a treatment of this potentially fatal allergy has led to intensive research on vaccine development. Here, we describe the design and initial characterization of a carrier-bound peptide derived from the most potent peanut allergen, Ara h 2, as a candidate vaccine. Based on the adjuvant capability of bacterial surface (S-) layers, a fusion protein of the S-layer protein SlpB from Lactobacillus buchneri CD034 and the Ara h 2-derived peptide AH3a42 was produced. This peptide comprised immunodominant B-cell epitopes as well as one T cell epitope. The fusion protein SlpB-AH3a42 was expressed in E. coli, purified, and tested for its IgE binding capacity as well as for its ability to activate sensitized rat basophil leukemia (RBL) cells. The capacity of Ara h 2-specific IgG rabbit-antibodies raised against SlpB-AH3a42 or Ara h 2 to inhibit IgE-binding was determined by ELISA inhibition assays using sera of peanut allergic patients sensitized to Ara h 2. IgE specific to the SlpB-AH3a42 fusion protein was detected in 69% (25 of 36) of the sera. Despite the recognition by IgE, the SlpB-AH3a42 fusion protein was unable to induce β-hexosaminidase release from sensitized RBL cells at concentrations up to 100ng per ml. The inhibition of IgE-binding to the natural allergen observed after pre-incubation of the 20 sera with rabbit anti-SlpB-AH3a42 IgG was more than 30% for four sera, more than 20% for eight sera, and below 10% for eight sera. In comparison, anti-Ara h 2 rabbit IgG antibodies inhibited binding to Ara h 2 by 48% ±13.5%. Our data provide evidence for the feasibility of this novel approach towards the development of a peanut allergen peptide-based carrier-bound vaccine. Our experiments further indicate that more than one allergen-peptide will be needed to induce a broader protection of patients allergic to Ara h 2.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.molimm.2017.02.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5386144PMC
May 2017