# Immunoproteomic Identification of Scedosporium boydii Antigens with Potential Diagnostic Interest in Cystic Fibrosis Patients

## TL;DR

Researchers identified specific fungal proteins that could help diagnose Scedosporium infections in cystic fibrosis patients more accurately.

## Contribution

The study introduces a novel immunoproteomic approach to identify Scedosporium boydii antigens for specific serodiagnosis in cystic fibrosis patients.

## Key findings

- 22 Scedosporium boydii proteins were identified as specific antigens recognized by patient and mouse sera.
- Key antigens include heat shock protein 70 and enzymes like 6-phosphogluconate dehydrogenase with high recognition rates.
- These antigens showed minimal cross-reactivity with Aspergillus or uninfected controls.

## Abstract

Fungal infections caused by Scedosporium/Lomentospora species are a significant threat to
patients
with cystic fibrosis (pwCF), ranking as the second most common filamentous
fungi in their airways after Aspergillus. Current
serodiagnostic methods, such as counterimmunoelectrophoresis and ELISA
using crude extracts, lack standardization and commercial availability
and often show cross-reactivity with other fungi. This study aimed
to identify specific Scedosporium boydii antigens with potential for serodiagnosis in pwCF. An immunoproteomic
approach combining two-dimensional polyacrylamide gel electrophoresis,
Western blot, and mass spectrometry was used to analyze the antigenic
profile of S. boydii against sera from
pwCF with positive cultures for Scedosporium/Lomentospora (Scedo+) and mice intravenously infected with
these fungi. We identified 22 proteins specifically recognized by
sera from pwCF Scedo+ and mice infected with S. boydii, but not by sera from pwCF or mice infected with Aspergillus spp. or uninfected controls. These proteins are primarily involved
in metabolism and exhibit catalytic activity. The most prevalent antigens
were the heat shock protein 70, 6-phosphogluconate dehydrogenase,
3-ketoacyl-CoA thiolase, and phosphoenolpyruvate carboxykinase, recognized
by 67–81% of pwCF Scedo + sera with minimal cross-reactivity
to negative samples. This work identifies promising candidates for
the specific serodiagnosis of Scedosporium/Lomentospora infections in pwCF. Data are available via
ProteomeXchange (PXD053392).