Project description:Histoplasma capsulatum is a thermally dimorphic fungus with worldwide distribution, and high incidence in the Americas. It is the etiologic agent of histoplasmosis, an important life-threatening systemic mycosis. Dimorphism is an important feature for fungal survival in different environments and it has been related to the virulence of H. capsulatum, and essential to the establishment of infection. Proteomic profiles have brought important contributions to the knowledge of metabolism and pathogenicity in several biological models. However, studies of the H. capsulatum proteome have been underexplored. In the present study, we report the first proteomic comparison between the mycelium and the yeast cells of H. capsulatum. Liquid chromatography coupled to mass spectrometry was used to evaluate the proteomic profile of the two phases of H. capsulatum. In summary, 214 proteins were only detected/or preferentially abundant in mycelium, while the same occurred to 335 proteins in yeast cells. In mycelium, enzymes related to the glycolytic pathway and to the alcoholic fermentation showed greater abundance, suggesting a higher use of anaerobic pathways for energy production. In yeast cells, proteins related to the tricarboxylic acid cycle and response to temperature stress showed high abundance. Proteins related to oxidative stress response or involved with cell wall metabolism were identified with differential abundance in both conditions. Validation of proteomic data was performed by enzymatic activity determination, western blot assays, or immunofluorescence microscopy. These experiments corroborated, directly or indirectly, the abundance of isocitrate lyase, 2-methylcitrate synthase, catalase B, and mannosyl-oligosaccharide-1,2-alpha-mannosidase in the mycelium and heat shock protein (HSP) 30, HSP60, glucosamine-fructose-6-phosphate aminotransferase, glucosamine-6-phosphate deaminase, and N-acetylglucosamine-phosphate mutase in yeast-cells. The proteomic profile associated functional classification analyzes of proteins provided a better understanding of the metabolic reorganization and cell wall remodeling on the yeast form of H. capsulatum.
Project description:The project aimmed to characterize the proteomic response of the human pathogenic fungus Histoplasma capsulatum to zinc poor environment. For that yeast cells were incubated in two conditions: zinc replete (with 20uM fo zinc sulfate) and zinc depleted (suppplemented with diethylenetriaminepentaacetic acid. Finaly teh proteins regulaed by zinc availability were identified.
Project description:Analyzed 84 genes from macrophages infected with Histoplasma capsulatum for changes in expression over 24 hours Macrophages infected with Histoplasma capsulatum were analyzed for alterations in apoptosis genes, 5 biological replicate (rep1-5)
Project description:To identify signaling pathways that are induced by macrophages infected with Histoplasma capsulatum, we examined the whole genome expression profile of murine bone marrow derived macrophages infected with conidia, the natural infectious particle of Histoplasma. Conidia induced the expression of signature Type I interferon response genes. The induction of a Type I interferon response was specific to conidia, yeast cells did not trigger the response. Macrophages that lack the Type I interferon receptor, IFNAR1, were infected and compared to wild-type macrophages. The expression of some Type I IFN response genes are dependent upon Keywords: Murine bone marrow derived macrophage transcriptional response to infection with Histoplasma capsulatum conidia We analyzed a series of 24 MEEBO arrays on which were hybed RNA amplified from bone marrow derived macrophages from C57BL/6 (WT) or ifnar1-/- mice either mock infected or infected with H. capsulatum conidia or yeast cells.
Project description:Histoplasma capsulatum is a fungal pathogen that infects both healthy and immunocompromised hosts. In endemic regions, H. capsulatum grows in the soil and causes respiratory and systemic disease when inhaled by humans. An interesting aspect of H. capsulatum biology is that it adopts specialized developmental programs in response to its environment. In the soil, it grows as filamentous chains of cells (mycelia) that produce asexual spores (conidia). When the soil is disrupted, conidia aerosolize and are inhaled by mammalian hosts. Inside a host, conidia germinate into yeast-form cells that colonize immune cells and cause disease. Despite the ability of conidia to initiate infection and disease, they have not been explored on a molecular level. Here we develop methods to purify H. capsulatum conidia and show that these cells germinate into either filaments at room temperature or into yeast-form cells at 37C. Conidia internalized by macrophages germinate into the yeast form and proliferate within the macrophages, ultimately lysing the host cells. Similarly, infection of mice with purified conidia is sufficient to establish infection and yield viable yeast-form cells in vivo. To characterize conidia on a molecular level, we perform whole-genome expression profiling of conidia, yeast, and mycelia from two highly diverged H. capsulatum strains. In parallel, we use homology and protein domain analysis to manually annotate the predicted genes of both strains. Analyses of the resultant data define sets of transcripts that reflect the unique molecular states of H. capsulatum conidia, yeast and mycelia. This series gives the results for the G217B strain.
Project description:Histoplasma capsulatum is a fungal pathogen that infects both healthy and immunocompromised hosts. In endemic regions, H. capsulatum grows in the soil and causes respiratory and systemic disease when inhaled by humans. An interesting aspect of H. capsulatum biology is that it adopts specialized developmental programs in response to its environment. In the soil, it grows as filamentous chains of cells (mycelia) that produce asexual spores (conidia). When the soil is disrupted, conidia aerosolize and are inhaled by mammalian hosts. Inside a host, conidia germinate into yeast-form cells that colonize immune cells and cause disease. Despite the ability of conidia to initiate infection and disease, they have not been explored on a molecular level. Here we develop methods to purify H. capsulatum conidia and show that these cells germinate into either filaments at room temperature or into yeast-form cells at 37C. Conidia internalized by macrophages germinate into the yeast form and proliferate within the macrophages, ultimately lysing the host cells. Similarly, infection of mice with purified conidia is sufficient to establish infection and yield viable yeast-form cells in vivo. To characterize conidia on a molecular level, we perform whole-genome expression profiling of conidia, yeast, and mycelia from two highly diverged H. capsulatum strains. In parallel, we use homology and protein domain analysis to manually annotate the predicted genes of both strains. Analyses of the resultant data define sets of transcripts that reflect the unique molecular states of H. capsulatum conidia, yeast and mycelia. This series gives the results for the G186AR strain.