title: Lactobacillus buchneri S-layer as carrier for an Ara h 2-derived peptide for peanut allergen-specific immunotherapy.
abstract: 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.
authors.affiliation: Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, 1190 Vienna, Austria.
authors.forename: Julia
authors.initials: J
authors.lastname: Anzengruber
authors.affiliation: Department of Pathophysiology and Allergy Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: Merima
authors.initials: M
authors.lastname: Bublin
authors.affiliation: Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, 1190 Vienna, Austria.
authors.forename: Eva
authors.initials: E
authors.lastname: Bönisch
authors.affiliation: Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, 1190 Vienna, Austria.
authors.forename: Bettina
authors.initials: B
authors.lastname: Janesch
authors.affiliation: Department of Pathophysiology and Allergy Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: Angelika
authors.initials: A
authors.lastname: Tscheppe
authors.affiliation: Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, 1190 Vienna, Austria.
authors.forename: Matthias L
authors.initials: ML
authors.lastname: Braun
authors.affiliation: Department of Pediatrics, Respiratory and Allergic Disease Division, Medical University Graz, Auenbruggerplatz 34, 8036 Graz, Austria.
authors.forename: Eva-Maria
authors.initials: EM
authors.lastname: Varga
authors.affiliation: Department of Dermatology, University Hospital St. Pölten, Karl Landsteiner University of Health Sciences, Propst-Führer-Strasse 4, 3100 St. Pölten, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Hafner
authors.affiliation: Department of Pathophysiology and Allergy Research, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
authors.forename: Heimo
authors.initials: H
authors.lastname: Breiteneder
authors.affiliation: Department of NanoBiotechnology, NanoGlycobiology Unit, Universität für Bodenkultur Wien, Muthgasse 11, 1190 Vienna, Austria.
authors.forename: Christina
authors.initials: C
authors.lastname: Schäffer
mesh_terms: D055516:2S Albumins, Plant / Q000276:immunology*; D000293:Adolescent; D000328:Adult; D052179:Antigens, Plant / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003888:Desensitization, Immunologic / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006023:Glycoproteins / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting; D007778:Lactobacillus; D008297:Male; D008562:Membrane Glycoproteins / Q000276:immunology*; D021183:Peanut Hypersensitivity / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D055815:Young Adult
chemical_list: D055516:2S Albumins, Plant; D052179:Antigens, Plant; C500890:Ara h 2 allergen, Arachis hypogaea; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; C055764:S-layer proteins
keywords: Ara h 2; Food allergy; Lactobacillus buchneri; Peanut allergy vaccine; S-layer protein