Abstract
Aspergillus fumigatus is an opportunistic fungal pathogen of the human airway that can cause a variety of chronic infections, typically in the context of pre-existing lung damage. The interaction of A. fumigatus with ex-vivo pig lung (EVPL) samples was characterized at the proteomic level to provide insights into how the fungus may interact with pulmonary tissue in vivo. This model has many advantages, because pigs share 90% immunological homology with humans and display many anatomical similarities. EVPL also retains resident immune cells, has richer cellular complexity compared to in-vitro models, and has a microbiome. Label-free quantitative proteomic analysis identified the metabolism and development of A. fumigatus on the EVPL alveolar sections; at 48 h, there was an increased abundance of proteins associated with carbon metabolism (e.g. malate dehydrogenase (+8.2 fold increase)), and amino acid metabolism and biosynthesis (e.g. 5-methyltetrahydropteroyltriglutamate - homocysteine S-methyltransferase, (+5.04 fold)) at 72 h. Porcine tissue remained responsive to the pathogen with proteins that increased in abundance associated with innate immune recruitment (e.g. protein S100-A8 (+28.5 fold) and protein S100-A9 (calgranulin-B) (+7.25 fold)) at 24 h, while proteins associated with neutrophil degranulation (e.g. elastase, neutrophil (-2.74 fold)) decreased in abundance. At 96 h, the infected tissue demonstrated enhanced abundance of fibrotic markers (e.g. fibrillin 1, collagen type IV alpha 1 chain, and alpha 2 chain, increased by + 16.44, +15.42 and + 11.95 fold, respectively). These results validate the use of this model for studying pathogen-host interactions and highlight how A. fumigatus interacts with pulmonary tissue during colonization.