Allergy Asthma Immunol Res.  2016 Mar;8(2):124-131. 10.4168/aair.2016.8.2.124.

Mimotopes for Api g 5, a Relevant Cross-reactive Allergen, in the Celery-Mugwort-Birch-Spice Syndrome

• Lukschal A
• Wallmann J
• Bublin M
• Hofstetter G
• Mothes-Luksch N
• Breiteneder H
• Pali-Scholl I
• Jensen-Jarolim E

• KMID: 2165928
• DOI: http://doi.org/10.4168/aair.2016.8.2.124

Abstract

PURPOSE
In the celery-mugwort-birch-spice syndrome, a significant proportion of IgE is directed against high molecular weight (HMW) glycoproteins, including the celery allergen Api g 5. BIP3, a monoclonal antibody originally raised against birch pollen, recognizes HMW allergens in birch and mugwort pollens, celery, and Apiaceae spices. Our aim was to generate mimotopes using BIP3 for immunization against the HMW allergens relevant in the celery-mugwort-birch-spice cross reactivity syndrome.
METHODS
Mimotopes were selected from a random-peptide display library by BIP3 and applied in IgE inhibition assays. The 3 phage clones with the highest inhibitory capacity were chosen for immunization of BALB/c mice. Mouse immune sera were tested for IgG binding to blotted birch pollen extract and used for inhibiting patients' IgE binding. Furthermore, sera were tested for binding to Api g 5, to horseradish peroxidase (HRP) as a second glycoprotein, or to non-glycosylated control allergen Phl p 5 in ELISA, and the specific Api g 5-specific IgG titers were determined.
RESULTS
Three rounds of biopanning resulted in phage clones exhibiting 7 different sequences including 1 dominant, 1-6-cyclo-CHKLRCDKAIA. Three phage clones had the capacity to inhibit human IgE binding and induced IgG to the HMW antigen when used for immunizing BALB/c mice. The induced BIP3-mimotope IgG reached titers of 1:500 specifically to Api g 5, but hardly reacted to glycoprotein HRP, revealing a minor role of carbohydrates in their epitope.
CONCLUSIONS
The mimotopes characterized in this study mimic the epitope of BIP3 relevant for Api g 5, one of the cross-reactive HMW allergens relevant in the celery-mugwort-birch-spice syndrome. BIP3 mimotopes may be used in the future for hyposensitization in this clinical syndrome by virtue of good and specific immunogenicity.

Keyword

Celery-mugwort-birch-spice syndrome; IgE Epitopes; food hypersensitivity; high molecular weight (HMW) allergens; mimotope; vaccination

MeSH Terms

Allergens
Animals
Apiaceae
Apium graveolens
Artemisia
Bacteriophages
Betula
Carbohydrates
Clone Cells
Enzyme-Linked Immunosorbent Assay
Food Hypersensitivity
Glycoproteins
Horseradish Peroxidase
Humans
Immune Sera
Immunization
Immunoglobulin E
Immunoglobulin G
Mice
Molecular Weight
Pollen
Spices
Vaccination
Virtues
Allergens
Carbohydrates
Glycoproteins
Horseradish Peroxidase
Immune Sera
Immunoglobulin E
Immunoglobulin G