- 作者：Brigitte Hantusch ; Sigurd Krieger ; Eva Untersmayr ; Isabella Schö ; ll ; Regina Knittelfelder ; Sabine Flicker ; Susanne Spitzauer ; Rudolf Valenta ; George Boltz-Nitulescu ; Otto Scheiner ; Erika Jensen-J
- 关键词：Phl p 5 ; major grass pollen allergen ; IgE ; B-cell epitope ; conformational epitope ; phage display ; mimotopes ; molecular modeling
- 刊名：Journal of Allergy and Clinical Immunology
- 出版年：2004
- 出版时间：December 2004
- 年：2004
- 卷：114
- 期：6
- 页码：1294-1300
- 全文大小：657 K
Background
Phl p 5 represents a major allergen of timothy grass pollen (Phleum pratense). Detailed knowledge about the structures responsible for IgE binding would allow the design of a novel generation of allergy vaccines.Objective
We aimed to characterize the IgE epitopes of Phl p 5a using phage display combined with a molecular modeling approach.
Methods
Phl p 5a–specific IgE from sera of patients with grass pollen allergy was used for screening of a random peptide phage library displaying constrained decamers.
Results
Fifteen phage clones that shared sequence motifs and could be grouped into families were selected by using Phl p 5a–specific IgE. Peptide alignment with the solvent-accessible amino acids of Phl p 5a revealed 3 sequence sections with frequent hits of identical or similar amino acids. On the surface of Phl p 5a, these sections assembled in compact patches, most likely representing conformational IgE epitopes, whereas no matching clusters were found on the back sides of the 2 Phl p 5a halves. In surface plasmon resonance experiments, the high-affinity interaction between IgE and Phl p 5 could be competed by phage-displayed peptides up to 24 % , indicating that they represent true epitope mimics (ie, mimotopes). Allergen-specific immunogenicity of the mimotopes was proved in Biozzi mice.
Conclusion
The selected mimotopes facilitated the localization of conformational IgE epitopes of Phl p 5. We suggest them to be suitable candidates for the development of an epitope-specific immunotherapy.