Quality and potency profile of eight recombinant isoallergens, largely mimicking total Bet v 1‐specific IgE binding of birch pollen

2019 ◽  
Vol 49 (5) ◽  
pp. 712-723 ◽  
Author(s):  
Christian Seutter von Loetzen ◽  
Andreas Reuter ◽  
Jelena Spiric ◽  
Thomas Schulenborg ◽  
Iris Bellinghausen ◽  
...  
Keyword(s):  
Birch Pollen ◽  
Specific Ige ◽  
Bet V 1 ◽  
Ige Binding

scholarly journals Agaricus blazei-Based Mushroom Extract Supplementation to Birch Allergic Blood Donors: A Randomized Clinical Trial

Nutrients ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2339 ◽  
Author(s):  
Faiza Mahmood ◽  
Geir Hetland ◽  
Ivo Nentwich ◽  
Mohammad Reza Mirlashari ◽  
Reza Ghiasvand ◽  
...  
Keyword(s):  
Placebo Group ◽  
Pollen Season ◽  
Blood Donors ◽  
Birch Pollen ◽  
Specific Ige ◽  
Basophil Activation ◽  
Pollen Extract ◽  
Agaricus Blazei ◽  
Oral Supplementation ◽  
Bet V 1

Since Agaricus blazei Murill (AbM) extract reduced specific IgE and ameliorated a skewed Th1/Th2 balance in a mouse allergy model, it was tested in blood donors with self-reported, IgE-positive, birch pollen allergy and/or asthma. Sixty recruited donors were randomized in a placebo-controlled, double-blinded study with pre-seasonal, 7-week, oral supplementation with the AbM-based extract AndosanTM. Before and after the pollen season, questionnaires were answered for allergic rhino-conjunctivitis, asthma, and medication; serum IgE was measured, and Bet v 1-induced basophil activation was determined by CD63 expression. The reported general allergy and asthma symptoms and medication were significantly reduced in the AbM compared to the placebo group during pollen season. During the season, there was significant reduction in specific IgE anti-Bet v 1 and anti-t3 (birch pollen extract) levels in the AbM compared with the placebo group. While the maximal allergen concentrations needed for eliciting basophil activation before the season, changed significantly in the placebo group to lower concentrations (i.e., enhanced sensitization) after the season, these concentrations remained similar in the AndosanTM AbM extract group. Hence, the prophylactic effect of oral supplementation before the season with the AbM-based AndosanTM extract on aeroallergen-induced allergy was associated with reduced specific IgE levels during the season and basophils becoming less sensitive to allergen activation.

scholarly journals Dissection of immunoglobulin E and T lymphocyte reactivity of isoforms of the major birch pollen allergen Bet v 1: potential use of hypoallergenic isoforms for immunotherapy.

1996 ◽  
Vol 183 (2) ◽  
pp. 599-609 ◽  
Author(s):  
F Ferreira ◽  
K Hirtenlehner ◽  
A Jilek ◽  
J Godnik-Cvar ◽  
H Breiteneder ◽  
...  
Keyword(s):  
T Cell ◽  
T Lymphocytes ◽  
Birch Pollen ◽  
Binding Activity ◽  
Pollen Allergen ◽  
Type I ◽  
Bet V 1 ◽  
Ige Binding ◽  
Birch Pollen Allergen

We dissected the T cell activation potency and the immunoglobulin (Ig) E-binding properties (allergenicity) of nine isoforms of Bet v 1 (Bet v 1a-Bet v 1l), the major birch pollen allergen. Immunoblot experiments showed that Bet v 1 isoforms differ in their ability to bind IgE from birch pollen-allergic patients. All patients tested displayed similar IgE-binding patterns toward each particular isoform. Based on these experiments, we grouped Bet v 1 isoforms in three classes: molecules with high IgE-binding activity (isoforms a, e, and j), intermediate IgE-binding (isoforms b, c, and f), and low/no IgE-binding activity (isoforms d, g, and 1). Bet v 1a, a recombinant isoform selected from a cDNA expression library using IgE immunoscreening exhibited the highest IgE-binding activity. Isoforms a, b, d, e, and 1 were chosen as representatives from the three classes for experimentation. The potency of each isoallergen to activate T lymphocytes from birch pollen-allergic patients was assayed using peripheral blood mononuclear cells, allergen-specific T cell lines, and peptide-mapped allergen-specific T cell clones. Among the patients, some displayed a broad range of T cell-recognition patterns for Bet v 1 isoforms whereas others seemed to be restricted to particular isoforms. In spite of this variability, the highest scores for T cell proliferative responses were observed with isoform d (low IgE binder), followed by b, 1, e, and a. In vivo (skin prick) tests showed that the potency of isoforms d and 1 to induce typical urticarial type 1 reactions in Bet v 1-allergic individuals was significantly lower than for isoforms a, b, and e. Taken together, our results indicate that hypoallergenic Bet v 1 isoforms are potent activators of allergen-specific T lymphocytes, and Bet v 1 isoforms with high in vitro IgE-binding activity and in vivo allergenicity can display low T cell antigenicity. Based on these findings, we propose a novel approach for immunotherapy of type I allergies: a treatment with high doses of hypoallergenic isoforms or recombinant variants of atopic allergens. We proceed on the assumption that this measure would modulate the quality of the T helper cell response to allergens in vivo. The therapy form would additionally implicate a reduced risk of anaphylactic side effects.

scholarly journals The Effect of Birch Pollen Immunotherapy on Apple and rMal d 1 Challenges in Adults with Apple Allergy

Nutrients ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 519 ◽  
Author(s):  
Johanna van der Valk ◽  
Birgit Nagl ◽  
Roy Gerth van Wljk ◽  
Barbara Bohle ◽  
Nicolette de Jong
Keyword(s):  
Skin Prick Test ◽  
Challenge Test ◽  
Birch Pollen ◽  
Food Challenge ◽  
Specific Ige ◽  
P Value ◽  
Double Blind ◽  
P Values ◽  
Prick Test ◽  
Bet V 1

Background: A proportion of patients allergic to birch pollen are also allergic to pit fruit. The objective of this study was to investigate the effect of immunotherapy with birch pollen on birch-pollen-related apple allergy. Method: Patients with birch pollen immunotherapy underwent a skin-prick test with birch pollen, apple and rMal d 1, global assessments and nasal challenges with birch pollen, open food challenge with apple and a double-blind, placebo-controlled test with rMal d 1 at the start of and during the immunotherapy. Measurements of specific IgE in response to Bet v 1 and rMal d 1 and IgG4 in response to Bet v 1 and rMal d 1 took place. Results: Six of eight patients demonstrated an improvement of nasal challenge test results and all patients improved on global assessment during the immunotherapy. The median oral dose of apple required to elicit a reaction increased but was not statistically significant. The patients showed a decrease in skin-prick test values in response to birch pollen (1.05 to 0.36), apple (0.78 to 0.25) and rMal d 1 (0.51 to 0.10) with p-values of 0.04, 0.03 and 0.06, respectively and a decrease of specific IgE in response to Bet v 1 (10.66 kU/L to 5.19 kU/L) and rMal d 1 (0.99 to 0.61 kU/L) with p-values of 0.01 and 0.05, respectively. Only the median specific IgG4 value to Bet v 1 increased from 0.05 to 1.85 mg/L (p-value of 0.02) and not to IgG4 rMal d 1 (0.07 to 0.08 kU/L). Conclusion: The beneficial effects of immunotherapy for birch pollen were accompanied by a limited effect on apple allergy.

scholarly journals Depigmented Allergoids Reveal New Epitopes with Capacity to Induce IgG Blocking Antibodies

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
M. Angeles López-Matas ◽  
Mayte Gallego ◽  
Víctor Iraola ◽  
Douglas Robinson ◽  
Jerónimo Carnés
Keyword(s):  
Birch Pollen ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Bet V 1 ◽  
Ige Binding ◽  
Linear Epitopes ◽  
Specific Igg ◽  
Allergen Extracts ◽  
Blocking Antibodies ◽  
Specific Igg Antibodies

Background. The synthesis of allergen-specific blocking IgGs that interact with IgE after allergen immunotherapy (SIT) has been related to clinical efficacy. The objectives were to investigate the epitope specificity of IgG-antibodies induced by depigmented-polymerized (Dpg-Pol) allergoids and unmodified allergen extracts, and examine IgE-blocking activity of induced IgG-antibodies.Methods. Rabbits were immunized with native and Dpg-Pol extracts of birch pollen, and serum samples were obtained. Recognition of linear IgG-epitopes of Bet v 1 and Bet v 2 and the capacity of these IgG-antibodies to block binding of human-IgE was determined.Results. Serum from rabbits immunized with native extracts recognised 11 linear epitopes from Bet v 1, while that from Dpg-Pol-immunized animals recognised 8. For Bet v 2, 8 epitopes were recognized by IgG from native immunized animals, and 9 from Dpg-Pol immunized one. Dpg-Pol and native immunized serum did not always recognise the same epitopes, but specific-IgG from both could block human-IgE binding sites for native extract.Conclusions. Depigmented-polymerized birch extract stimulates the synthesis of specific IgG-antibodies which recognize common but also novel epitopes compared with native extracts. IgG-antibodies induced by Dpg-Pol effectively inhibit human-IgE binding to allergens which may be part of the mechanism of action of SIT.

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