Identification of IgE binding to Api g 1-derived peptides

Area of Science:

• Immunology
• Allergology
• Biochemistry

Background:

• Celery allergy is common in pollen-sensitized individuals, causing severe reactions.
• Current diagnostic methods like skin prick tests (SPTs) and specific immunoglobulin E (IgE) measurements lack predictive accuracy for clinical symptoms.
• Identifying specific IgE-binding epitopes is crucial for accurate celery allergy diagnosis.

Purpose of the Study:

• To identify specific IgE-binding peptides of the major celery allergen, Api g 1.0101.
• To develop and optimize an immunoassay for detecting IgE reactivity to these peptides.
• To evaluate the diagnostic potential of the developed assay in distinguishing celery-allergic from healthy individuals.

Main Methods:

• Synthesized Api g 1.0101 as an array of overlapping peptides.
• Probed synthesized peptides with sera from 21 celery-allergic and 17 healthy patients.
• Optimized immunoassay parameters including peptide length, density, incubation, and readout.

Main Results:

• Celery-allergic patients' sera showed IgE binding to three distinct regions of Api g 1.0101.
• A peptide containing amino acids 100-126 demonstrated the highest IgE binding, fivefold greater than in healthy controls.
• A specific peptide (VLVPTADGGSIC) within this region was recognized by all allergic patients' sera but none from healthy controls.

Conclusions:

• An improved immunoassay strategy effectively identifies specific IgE binding peptides in celery allergy.
• The assay demonstrates potential for distinguishing celery-allergic patients from healthy individuals.
• Further validation in a larger, well-defined patient cohort is warranted.