Project description:Background Sporothrix brasiliensis and Sporothrix schenckii are the main etiological agents of sporotrichosis. These pathogens release extracellular vesicles (EVs), which are key transport structures involved in virulence and host–pathogen interactions. EVs from S. brasiliensis and S. schenckii have been exclusively under liquid culture conditions, with analyses focused on their protein composition and functional roles. However, noinformation is currently available regarding the small molecule composition of Sporothrix EVs, and the extent to wich S. schenckii and S. brasiliensis share or differ in their EVs cargo remain unknown. Methods We isolated EVs from S. brasiliensis (strain 5110) and S. schenckii (strain 1099-18) following cultivation on solid medium, and characterized the samples using a combination of nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), proteomics, and small molecule identification. Based on the EV composition, subsequent analyses included biochemical assay to assess cell-assocaited enzyme activity and a functional model of Sporothrix adhesion to type I collagen in the presence of isoleucine-proline-isoleucine (IPI), a peptide component found in EVs produced by both S. schenckii and S. brasiliensis. Results EVs from both S. brasiliensis and S. schenckii exhibited a high protein diversity, encompassing components related to essential cellular processes and virulence mechanisms. Only a small fraction of the identified proteins was shared between the two species, and a similar pattern was observed for the small molecules. Among the common molecules was IPI, previously described in Cryptococcus EVs. IPI is an inhibitor of dipeptidyl peptidase IV (DPP4), which was detected on the surface of S. brasiliensis and S. schenckii. Both IPI and an antibody against DPP4 effectively reduced Sporothrix adhesion to type I collagen, a major component of the host extracellular matrix. Conclusion Our study reveals an unprecedented level of proteomic and metabolomic complexity in Sporothrix EVs, uncovering novel molecular features and identifying IPI as an inhibitor of fungal adhesion to collagen.
Project description:Sporotrichosis, an implantation mycosis caused by the dimorphic fungus Sporothrix schenckii, gained attention over the two last decades due to its broad geographic range and prevalence in tropical and subtropical areas. The dimorphic switching from hyphal form to the yeast form is essential for the pathogenesis of S. schenckii. During the mycelium-to-yeast transition, there are many changes in asexual development, yeast-phase cell formation, cell wall integrity, and melanin synthesis. However, the mechanisms of the signaling pathways associated with these process remain unclear. In this study, transcriptome sequencing of both the yeast stage and mycelium of S. schenckii was carried out. The results showed that 12217 genes, including genes involved in signal transduction and chitin synthesis, were expressed differentially between the two stages. According to these results, a map of the signaling pathways, related to the dimorphic switch, was drawn. Overall, the transcriptome data and analysis presented here lay the foundation for further research into the molecular mechanisms controlling the dimorphic switch of S. schenckii and support the development of anti-S. schenckii strategies targeting genes related to signaling pathways.
Project description:We report the global transcriptomic differences occurring between mold and yeast phases of S. schenckii including changes in gene expression profiles associated with these distinct cellular phenotypes. Moreover, we also propose a new genome annotation which reveals a more complex transcriptional architecture than previously assumed.
Project description:The pathogenic dimorphic fungus Sporothrix schenckii is the agent responsible for sporotrichosis, an important fungal infection with a worldwide distribution. Little is known about the population structure of S. schenckii, although recent molecular and phenotypic data seem to demonstrate that different genetic lineages exist within this species. The aim of this study was to determine, by sequence analysis of three protein coding loci (chitin synthase, beta-tubulin, and calmodulin), whether this variability is due to species divergence or intraspecific diversity in S. schenckii. We included in the analysis 60 isolates (59 of clinical and 1 of environmental origin) of this species from a wide geographical range. DNA sequence data from the three nuclear regions were used in a phylogenetic analysis. The combined analysis of the three loci revealed the presence of three major clades, one grouping all of the European isolates, another with only Brazilian isolates, and the third with isolates from other South American countries and Africa. A total of 14 100% bootstrap-supported nodes were shown, 6 of them representing putative phylogenetic species. Our data also demonstrated that most of these species prevail in different geographical regions.