Project description:RGS protein encoding genes gprK and rgsC deletion mutant microarray To identify the function of RGSs of A. fumigatus Biological replicates: WT vs. three deletion mutants, independently grown and harvested. One replicate per array
Project description:Microarray analysis was used to compare gene expression of Aspergillus fumigatus under two different sporulation temperatures, 17oC and 32oC, with an emphasis on genes encoding known or putative allergens of the fungus. The objective of the study was to investigate whether allergenic potencies of A. fumigatus spores produced under different sporulation temperatures would be influenced by temperature-dependent transcriptional regulation of allergenicity genes.
Project description:Plasmacytoid dendritic cells (pDCs) were initially considered as critical for innate immunity to viruses. However, our group has shown that pDCs bind to and inhibit the growth of Aspergillus fumigatus hyphae and that depletion of pDCs renders mice hypersusceptible to experimental aspergillosis. In this study, we examined pDC receptors responsible for hyphal recognition and downstream events in pDCs stimulated by A. fumigatus hyphae. Our data show that Dectin-2 but not Dectin-1 participates in hyphal recognition by pDCs and that Dectin-2 acts in cooperation with the FcRγ chain to trigger signaling responses. In addition, using confocal and electron microscopy we demonstrated that the interaction between pDCs and A. fumigatus induced the formation of pDC extracellular traps (pETs) containing DNA and citrullinated histone H3. Thus, these structures closely resembled those of neutrophil extracellular traps (NETs). Microarray analysis of the pDC transcriptome upon A. fumigatus infection demonstrated up-regulated expression of genes previously associated with viral infections or apoptosis. Moreover, the abundant expression of type I Interferon-encoding genes seen in CpG-stimulated pDCs was absent in the pDCs infected with A. fumigatus hyphae. Thus, human pDCs directly recognize A. fumigatus hyphae via Dectin-2. This interaction leads to formation of pET and triggers a distinct pattern of pDC gene expression.
Project description:Genomic DNA from five strains, Aspergillus fumigatus Af71, Aspergillus fumigatus Af294, Aspergillus clavatus, Neosartorya fenneliae, and Neosartorya fischeri, were co-hybridized with that of Aspergillus fumigatus Af293 and compared.
Project description:Aspergillus fumigatus is the most common opportunistic mold pathogen of humans, causing invasive diseases in immunocompromised patients. In these patients, the fungus can invade the lungs and other organs, causing severe damage. Penetration of the pulmonary epithelium is a key step in the infectious process. A. fumigatus produces extracellular proteases to degrade the structural barriers of the host. The A. fumigatus transcription factor PrtT controls the expression of multiple secreted proteases. PrtT shows similarity to the fungal Gal4-type Zn(2)-Cys(6) DNA-binding domain of several transcription factors. In this work, we further investigate the function of this transcription factor by performing a transcriptional and a proteomic analysis of the ΔprtT mutant. The microarray analysis revealed several unexpected findings. In addition to a decrease in protease expression, expression of genes involved in iron uptake and ergosterol synthesis was dramatically decreased in the ΔprtT mutant. A second finding of interest is that deletion of PrtT resulted in the upregulation of four secondary metabolite clusters, including genes for the biosynthesis of pseurotin A. The proteomic analysis identified 15 proteins secreted by the A. fumigatus WT strain when grown on protein-rich skim-milk medium. Of these, the ΔprtT mutant expressed reduced levels of ALP1 protease, TppA tripeptidyl peptidase and a serine peptidase and increased levels of FAD-oxygenase, AspF chitosinase, EglC endoglucanase and Bgt1 glucanosyltransferase compared to the WT strain. This report highlights the complexity of gene regulation by PrtT.
Project description:Calcineurin plays an important role in the control of cell morphology and virulence in fungi. Calcineurin is a serine/threonine-specific protein phosphatase heterodimer consisting of a catalytic subunit A and a regulatory Ca2+/Calmodulin binding subunit. A mutant of A. fumigatus lacking the calcineurin A (calA) catalytic subunit exhibited defective hyphal morphology related to apical extension and branching growth, which resulted in drastically decreased filamentation. Here, we investigated which pathways are influenced by A. fumigatus calcineurin during proliferation by comparatively determining the transcriptional profile of A. fumigatus wild type and delta calA mutant strains. Our results showed that although the mitochondrial function is reduced in the delta calA mutant strain, its respiratory chain is functional and the mutant has increased alternative oxidase (aoxA) mRNA accumulation and activity. Furthermore, we identified several genes that encode transcription factors that have increased mRNA expression in the delta calA mutant and that could be involved in the Cal-CrzA pathway. Deletion mutants for these transcription factors had also reduced susceptibility to itraconazole, caspofungin, and sodium dodcyl sulfate.
Project description:Aspergillus fumigatus is an important human pathogen and a leading fungal killer. This study aimed to determine the small RNA repertoire of A. fumigatus in conidia and mycelium grown for 24 or 48 hours in liquid culture.
Project description:Aspergillus fumigatus is an important human pathogen and a leading fungal killer. This study aimed to determine the tRNA fragment and tRNA half repertoire of A. fumigatus in wild-type conidia and mycelium grown for 24 or 48 hours in liquid culture.