Aspergillus fumigatus is one of the most common airborne fungi capable of causing invasive mycoses in immunocompromised patients and allergic diseases in susceptible individuals. In both cases, fungal surface proteins mediate the first contact with the human immune system to evade immune responses or to induce hypersensitivity. Several methods have been established to study the surface proteome (surfome) of A. fumigatus, like trypsin shaving, glucanase treatment, or formic acid extraction. Biotinylation coupled with LC-MS/MS identification of peptides is a particularly efficient method to identify the surface exposed regions of proteins that potentially mediate interaction with the host. After biotinylation of ... More
Aspergillus fumigatus is one of the most common airborne fungi capable of causing invasive mycoses in immunocompromised patients and allergic diseases in susceptible individuals. In both cases, fungal surface proteins mediate the first contact with the human immune system to evade immune responses or to induce hypersensitivity. Several methods have been established to study the surface proteome (surfome) of A. fumigatus, like trypsin shaving, glucanase treatment, or formic acid extraction. Biotinylation coupled with LC-MS/MS identification of peptides is a particularly efficient method to identify the surface exposed regions of proteins that potentially mediate interaction with the host. After biotinylation of surface proteins during spore germination, we detected 314 different surface proteins, including several well-known proteins like RodA, CcpA, and DppV, as well as several allergens, heat shock proteins (HSPs), and previously undescribed surface proteins. Using immunofluorescence microscopy, we confirmed the surface localization of three HSPs, which may have moonlighting functions. Collectively, our study generated a comprehensive data set of the A. fumigatus surfome, which complements already existing A. fumigatus surface proteome data and allows us to propose a common core set of A. fumigatus surface proteins. In addition, our study uncovers the surface-exposed regions of many proteins on the surface of spores or hyphae. These surface exposed regions are candidates for direct interaction with host cells and may represent antigenic epitopes that either induce protective immune responses or mediate immune evasion. Thus, the comprehensive datasets provided and compiled here represent reasonable immunotherapy and diagnostic targets for future investigations.
