scholarly journals Isolation of nanobodies with potential to reduce patients´ IgE binding to Bet v 1 (68/100 characters)

Allergy ◽  
2021 ◽  
Author(s):  
Ines Zettl ◽  
Tatiana Ivanova ◽  
Maria R. Strobl ◽  
Christina Weichwald ◽  
Oksana Goryainova ◽  
...  
Keyword(s):  
Bet V 1 ◽  
2004 ◽  
Vol 385 (1) ◽  
pp. 319-327 ◽  
Author(s):  
Regina WICHE ◽  
Michaela GUBESCH ◽  
Herbert KÖNIG ◽  
Kay FÖTISCH ◽  
Andreas HOFFMANN ◽  
...  

Birch (Betula verrucosa) pollen-associated food allergy is a well-characterized syndrome, which is due to the cross-reactivity of IgE antibodies to homologous allergens in various foods. One crossreacting area on the major birch pollen allergen Bet v 1 and its homologue in cherry (Prunus avium) Pru av 1 has already been identified. This is the so-called ‘P-loop’ region, which encompasses amino acid residues around position 45 and is found on the two virtually identical tertiary protein structures. We tried to determine an additional IgE cross-reacting patch on Pru av 1 and Bet v 1. The putative IgE-binding region on Pru av 1 was localized with a mAb (monoclonal antibody) that was generated against Bet v 1, and cross-reacts with several Bet v 1 homologues in food and inhibits the binding of patients' IgE to Pru av 1. mAb reactivity pattern was analysed and amino acid positions 28 and 108 of Pru av 1 were selected and mutated by site-directed mutagenesis. The Pru av 1 mutants were produced as recombinant proteins and characterized for their folding, mAb- and IgE-binding capacity and allergenic potency with a cellular assay using the humanized rat basophilic leukaemia cell line RBL-25/30. Amino acid position 28 is involved in a second major IgE-binding region on Pru av 1 and probably on Bet v 1. The identification of this second major IgE-binding region is an essential prerequisite to understand the phenomenon of cross-reactivity and its clinical consequences, and to produce hypoallergenic proteins for an improved immunotherapy of type I allergy.


2019 ◽  
Vol 49 (5) ◽  
pp. 712-723 ◽  
Author(s):  
Christian Seutter von Loetzen ◽  
Andreas Reuter ◽  
Jelena Spiric ◽  
Thomas Schulenborg ◽  
Iris Bellinghausen ◽  
...  

Allergy ◽  
2004 ◽  
Vol 59 (12) ◽  
pp. 1277-1284 ◽  
Author(s):  
A. L. Karlsson ◽  
R. Alm ◽  
B. Ekstrand ◽  
S. Fjelkner-Modig ◽  
A. Schiott ◽  
...  

1996 ◽  
Vol 183 (2) ◽  
pp. 599-609 ◽  
Author(s):  
F Ferreira ◽  
K Hirtenlehner ◽  
A Jilek ◽  
J Godnik-Cvar ◽  
H Breiteneder ◽  
...  

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.


2012 ◽  
Vol 91 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Kavita Reginald ◽  
Julia Eckl‐Dorna ◽  
Domen Zafred ◽  
Margarete Focke‐Tejkl ◽  
Christian Lupinek ◽  
...  
Keyword(s):  
Bet V 1 ◽  

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
M. Angeles López-Matas ◽  
Mayte Gallego ◽  
Víctor Iraola ◽  
Douglas Robinson ◽  
Jerónimo Carnés

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.


2003 ◽  
Vol 376 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Philipp NEUDECKER ◽  
Katrin LEHMANN ◽  
Jörg NERKAMP ◽  
Tanja HAASE ◽  
Andrea WANGORSCH ◽  
...  

Birch pollinosis is often accompanied by adverse reactions to food due to pollen-allergen specific IgE cross-reacting with homologous food allergens. The tertiary structure of Pru av 1, the major cherry (Prunus avium) allergen, for example, is nearly identical with Bet v 1, the major birch (Betula verrucosa) pollen allergen. In order to define cross-reactive IgE epitopes, we generated and analysed mutants of Pru av 1 and Api g 1.0101, the major celery (Apium graveolens) allergen, by immunoblotting, EAST (enzyme allergosorbent test), CD and NMR spectroscopy. The mutation of Glu45 to Trp45 in the P-loop region, a known IgE epitope of Bet v 1, significantly reduced IgE binding to Pru av 1 in a subgroup of cherry-allergic patients. The backbone conformation of Pru av 1 wild-type is conserved in the three-dimensional structure of Pru av 1 Trp45, demonstrating that the side chain of Glu45 is involved in a cross-reactive IgE epitope. Accordingly, for a subgroup of celery-allergic patients, IgE binding to the homologous celery allergen Api g 1.0101 was enhanced by the mutation of Lys44 to Glu. The almost complete loss of IgE reactivity to the Pru av 1 Pro112 mutant is due to disruption of its tertiary structure. Neither the mutation Ala112 nor deletion of the C-terminal residues 155–159 influenced IgE binding to Pru av 1. In conclusion, the structure of the P-loop partially explains the cross-reactivity pattern, and modulation of IgE-binding by site-directed mutagenesis is a promising approach to develop hypo-allergenic variants for patient-tailored specific immunotherapy.


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