Peptide detection of fungal functional amyloids in infected tissue
Melissa C Garcia-Sherman1, Nataliya Lysak1, Alexandra Filonenko1
1Department of Biology, City University of New York Brooklyn College, Brooklyn, New York, United States of America.
Abstract:
Many fungal cell adhesion proteins form functional amyloid patches on the surface of adhering cells. The Candida albicans Agglutinin-like sequence (Als) adhesins are exemplars for this phenomenon, and have amyloid forming sequences that are conserved between family members. The Als5p amyloid sequence mediates amyloid fibril formation and is critical for cell adhesion and biofilm formation, and is also present in the related adhesins Als1p and Als3p. We have developed a fluorescent peptide probe containing the conserved Als amyloid-forming sequence. This peptide bound specifically to yeast expressing Als5p, but not to cells lacking the adhesin. The probe bound to both yeast and hyphal forms of C. albicans. Δals1/Δals3 single and double deletion strains exhibited reduced fluorescence, indicating that probe binding required expression of these proteins. Additionally, the Als peptide specifically stained fungal cells in abscesses in autopsy sections. Counterstaining with calcofluor white showed colocalization with the amyloid peptide. In addition, fungi in autopsy sections derived from the gastrointestinal tract showed colocalization of the amyloid-specific dye thioflavin T and the fluorescent peptide. Collectively, our data demonstrate that we can exploit amyloid sequence specificity for detection of functional amyloids in situ.
Insights
Researchers developed a fluorescent peptide probe to detect functional amyloid proteins on fungal cell surfaces. This probe successfully identified fungal amyloids in clinical samples, demonstrating a new method for in situ detection.
Area of Science:
- Microbiology
- Biochemistry
- Medical Mycology
Background:
- Fungal cell adhesion proteins, like Candida albicans Agglutinin-like sequence (Als) adhesins, often form functional amyloid patches.
- The amyloid-forming sequence in Als5p is crucial for cell adhesion and biofilm formation and is conserved in related adhesins (Als1p, Als3p).
Purpose of the Study:
- To develop a specific fluorescent peptide probe for detecting functional amyloid sequences in fungal adhesins.
- To validate the probe's specificity and efficacy in detecting fungal amyloids in vitro and in clinical specimens.
Main Methods:
- Development of a fluorescent peptide probe based on the conserved Als amyloid-forming sequence.
- Testing probe binding specificity against Candida albicans strains with and without specific Als adhesins.
- In situ staining of fungal cells in autopsy tissue sections (abscesses and gastrointestinal tract) using the fluorescent peptide probe and thioflavin T.
Main Results:
- The fluorescent peptide probe specifically bound to yeast expressing Als5p and to both yeast and hyphal forms of C. albicans.
- Deletion strains (Δals1/Δals3) showed reduced fluorescence, confirming the requirement for these adhesins.
- The probe successfully stained fungal cells in clinical autopsy sections, colocalizing with amyloid markers like calcofluor white and thioflavin T.
Conclusions:
- A novel fluorescent peptide probe can specifically detect functional fungal amyloids in situ.
- This approach offers a valuable tool for identifying and characterizing fungal adhesin amyloids in clinical settings.
- Exploiting amyloid sequence specificity enables targeted detection of functional amyloids within biological samples.
More Related Videos
07:27Methods for Detecting Cytotoxic Amyloids Following Infection of Pulmonary Endothelial Cells by Pseudomonas aeruginosa
Published on: July 12, 2018
10:48SDS-PAGE/Immunoblot Detection of Aβ Multimers in Human Cortical Tissue Homogenates using Antigen-Epitope Retrieval
Published on: April 23, 2010
