# Pathogen-specific IgE-reactive cytosolic allergenic epitopes of Aspergillus fumigatus for immunodiagnostic/immunotherapeutic applications against allergic aspergillosis

## TL;DR

This study identifies specific allergens and epitopes from Aspergillus fumigatus that could improve diagnosis and treatment of allergic bronchopulmonary aspergillosis.

## Contribution

The study discovers 13 allergenic proteins and several epitopes specific to ABPA patients, offering new targets for diagnostics and immunotherapy.

## Key findings

- 18 allergenic proteins were identified from A. fumigatus cytosolic fractions using patient sera.
- 13 proteins showed significant immunoreactivity specific to ABPA patient sera.
- In silico analysis identified 9 B-cell and 4 T-cell epitopes with antigenic potential.

## Abstract

Aspergillosis: Global disease.

Pathogen-specific allergen/epitope.

Utility in diagnostics and therapeutics.

The online version contains supplementary material available at 10.1186/s12941-025-00846-z.

Aspergillus fumigatus is a significant fungal pathogen responsible for allergic bronchopulmonary aspergillosis (ABPA), a global respiratory disease characterized by high morbidity and mortality. Accurate diagnosis of ABPA remains challenging due to the overlap of clinical and radiological features with other respiratory infections. This study aimed to identify A. fumigatus specific antigens and epitopes to advance immunodiagnostic and immunotherapeutic strategies for ABPA. Clinically confirmed ABPA patients were recruited, and their sera were tested for immunoreactivity against A. fumigatus crude and recombinant allergens. Proteomic analysis was done by employing two-dimensional electrophoresis (2DE) immunoblotting of A. fumigatus cytosolic fractions using sera from 10 individual patients. IgE-reactive spots identified via Q-TOF mass spectrometry revealed 18 allergenic proteins. Among these, two known allergens (Asp-f12 and Asp-f22) and three predicted allergens (sorbitol/xylulose-reductase, Hsp70-chaperone Hsp88, and Hsp70) exhibited cross-reactivity with allergens from other fungi. Notably, 13 allergenic proteins demonstrated significant immunoreactivity specific to ABPA patient sera. In silico epitope analysis identified 9 A. fumigatus specific B-cell and 4 T-cell epitopes with antigenic potential. Molecular docking studies confirmed the binding of representative B-cell and T-cell epitopes to their respective receptors (B-cell receptor and MHC-II complex), demonstrating receptor-specific interactions. These findings highlight pathogen-specific allergens and epitopes that could serve as valuable resources for developing targeted immunodiagnostic and immunotherapeutic tools. This approach may improve the clinical management of ABPA and help reduce its global disease burden.

The online version contains supplementary material available at 10.1186/s12941-025-00846-z.