Pollen-Food Allergy Syndrome: From Food Avoidance to Deciphering the Potential Cross-Reactivity between Pru p 3 and...

Area of Science:

• Immunology
• Allergology
• Molecular Biology

Background:

• Nonspecific lipid transfer proteins (nsLTPs) like Ole e 7 (olive pollen) and Pru p 3 (peach) can cause cross-reactive anaphylaxis.
• This cross-reactivity contributes to pollen-food syndromes, necessitating detailed molecular investigation.

Purpose of the Study:

• To map specific IgE (sIgE)-binding epitopes of Ole e 7 and Pru p 3.
• To investigate the molecular basis of cross-reactivity between Ole e 7 and Pru p 3.

Main Methods:

• Epitope mapping using LC-MS on IgE-bound peptides from Ole e 7 and Pru p 3.
• Analysis of sera from patients monosensitized to Ole e 7, Pru p 3, or bisensitized.

Main Results:

• Previously described epitopes for Ole e 7 and Pru p 3 were confirmed.
• A specific Ole e 7 peptide (KSALALVGNKV) and a Pru p 3 peptide (ISASTNCATVK) were recognized by all patient groups.
• High local sequence identity (50-57%) was observed between cross-reactive peptide fragments, despite low overall sequence identity (32.6%).

Conclusions:

• Specific sIgE-binding epitopes for Ole e 7 were mapped, enabling improved diagnostic strategies.
• Structural homology and shared key residues, rather than significant sequence similarity, likely drive the cross-reactivity between Ole e 7 and Pru p 3 nsLTPs.