Anti-idiotypic Fab Fragments Image a Conserved N-terminal Epitope Patch of Grass Pollen Allergen Phl p 1

Anna Lukschal1, Jan Fuhrmann2, Juryj Sobanov1, Dirk Neumann2, Julia Wallmann1, Regina Knittelfelder1, Wolfgang Hemmer3, Otto Scheiner1, Monique Vogel4, Beda M. Stadler4, Erika Jensen-Jarolim*, 1, Krisztina Szalai1
1 Department of Pathophysiology and Allergy Research; Center of Pathophysiology, Infectiology & Immunology; Medical University of Vienna, Vienna, Austria
2 Scientific Consilience, Saarland University, Saarbrücken, Germany
3 Floridsdorf Allergy Center (FAZ), Vienna, Austria
4 Institute of Immunology, University of Bern, Inselspital, Bern, Switzerland

© 2011 Lukschal et al;

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Correspondence: * Address correspondence to this author at the Department of Pathophysiology and Allergy Research, Center of Pathophysiology, Infectiology & Immunology, Medical University of Vienna; Waehringer Guertel 18-20, A- 1090 Vienna; Tel: +43/1/40400-5110; Fax: +43/1/40400-6188; E-mail:


Background and Aims:

Naturally occurring anti-idiotypic antibodies structurally mimic the original antibody epitope. Anti-idiotypes, therefore, are interesting tools for the portrayal of conformational B-cell epitopes of allergens. In this study we used this strategy particularly for major timothy grass pollen (Phleum pratense) allergen Phl p 1.

Methods and Results:

We used a combinatorial phage display library constructed from the peripheral IgG repertoire of a grass pollen allergic patient which was supposed to contain anti-idiotypic Fab specificities. Using purified anti-Phl p 1 IgG for biopanning, several Fab displaying phage clones could be isolated. 100 amplified colonies were screened for their binding capacity to anti-Phl p 1-specific antibodies, finally resulting in four distinct Fab clones according to sequence analysis. Interestingly, heavy chains of all clones derived from the same germ line sequence and showed high homology in their CDRs. Projecting their sequence information on the surface of the natural allergen Phl p 1 (PDB ID: 1N10) indicated matches on the N-terminal domain of the homo-dimeric allergen, including the bridging region between the two monomers. The resulting epitope patches were formed by spatially distant sections of the primary allergen sequence.


In this study we report that anti-idiotypic specificities towards anti-Phl p 1 IgG, selected from a Fab library of a grass pollen allergic patient, mimic a conformational epitope patch being distinct from a previously reported IgE epitope area.

Keywords: Grass pollen, allergy, B-cell epitope, Phl p 1, mimotope.