Project description:We identified two effective fungal elicitors, L01 (Guignardia) and J02 (Diaporthe). The two fungal elicitors might activate Taxol biosynthesis by regulating the MYC2a-controlled JA signaling pathway.
Project description:Fungal spores, abundant in the environment, are a major cause of asthma. But the precise host response that triggers fungal allergic airway inflammation remains unclear. We found that CD11c+ DCs and CD4+ T cells are essential for development of airway inflammation in mice when repeatedly exposed to inhaled spores. To delinate which DC subsets are mediating fungal allergic inflammation we undertook single cell RNAseq of DCs isolated from the lungs of mice exposed to fungal spores. This identified precise subsets altered upon spore exposure and following targeted removal identified distinct DC subsets (Mgl2+ cDC2s) that are essential for fungal allergic airway inflammation.
Project description:As transition metal availability is very limited inside the human host, fungal pathogens have evolved sophisticated mechanisms to uptake and utilize these micronutrients at the infection interface. While considerable attention was turned into iron, copper and zinc acquisition mechanisms and their importance in fungal fitness, less was done regarding either the role of Mn in infectious processes or the cellular mechanism by which fungal cells achieve their Mn-homeostasis. Here, we undertook a transcriptional profiling of the pathogenic fungus Candida albicans experiencing both Mn starvation and excess to comprehensibly capture biological processes that are modulated by Mn. We uncovered that Mn scarcity influence diverse biological processes associated with fungal fitness including morphogenetic switch, invasion of host cells and antifungal sensitivity. We also uncovered that Mn levels influence the abundance of iron and zinc emphasizing the complex crosstalk between ions metals. Deletion of SMF12, a member of Mn Nramp transporters confirmed its contribution to Mn uptake. In accordance with the RNA-seq data, smf12 was unable to form hyphae and damage host cells, and exhibited sensitivity to azole antifungals. We also found that unfolded protein response (UPR), likely activated by decreased glycosylation under Mn limitation, was essential to promote C. albicans growth. RNA-seq profiling of cells exposed to Mn excess uncovered that the UPR signaling was also essential to bypass Mn toxicity. Collectively, this study underscores the importance of Mn homeostasis in fungal virulence, and comprehensively provides a transcriptional portrait of biological functions that are modulated by Mn in a fungal pathogen.
Project description:RATIONALE: Gathering information about how often fungal infections of the blood occur in patients with cancer or in patients who have undergone stem cell transplant may help doctors learn more about the disease.
PURPOSE: This natural history study is collecting information about fungal infections of the blood over time from patients with cancer or from patients who have undergone a stem cell transplant.
Project description:The effects of two years' winter warming on the overall fungal functional gene structure in Alaskan tundra soil were studies by the GeoChip 4.2 Resuts showed that two years' winter warming changed the overall fungal functional gene structure in Alaskan tundra soil.
Project description:MicroRNAs (miRNAs) are small, stable non-coding RNA molecules with regulatory function and marked tissue specificity that post-transcriptionally regulate gene expression, however their role in fungal keratitis remain unknown. Our purpose was to identify the miRNAs in human cornea from fungal keratitis patients and understand their key role in regulation of pathogenesis. Corneal samples from normal cadaver (n=3) and fungal keratitis (n=5) patients were pooled separately and total RNA was extracted. Deep sequencing was done using Illumina HiSeq1000 platform to identify miRNA profile. We identified seventy five differentially expressed miRNAs in fungal keratitis corneas. Select miRNAs were validated by real-time RT-PCR (Q-PCR). We predicted their role in regulating target genes in several pathways by combining miRNA target genes and pathway analysis, and mRNA expression of select target genes were further analysed by Q-PCR. MiR-21-5p, miR-223-3p, miR-146b-5p, miR-155-5p, miR-511-5p were found to be involved in inflammatory and immune responses, regulating Toll like receptor signaling pathways, which is of particular interest. MiR-451a with an increased expression in keratitis may have a role in wound healing by targeting Macrophage Migration Inhibitory Factor (MIF). Further, we highlighted that Neurotrophin signaling pathway may play a role in wound healing process. One novel miRNA was also detected in cornea. In conclusion, several miRNAs with high expression in fungal keratitis corneas point towards their role in regulation of pathogenesis. Further insights in understanding miRNAs role in wound healing and inflammation may help design new therapeutic strategies.
Project description:Lysine acetylation is critical in regulating important biological processes in many organisms, yet little is known about acetylome evolution and its contribution to phenotypic diversity. Here, we compare the acetylomes of baker’s yeast and the three deadliest human fungal pathogens, Cryptococcus neoformans, Candida albicans, and Aspergillus fumigatus. Using mass spectrometry enriched for acetylated peptides together with public data from Saccharomyces cerevisiae, we show that fungal acetylomes are characterized by dramatic evolutionary dynamics and limited conservation in core biological processes. Notably, the levels of protein acetylation in pathogenic fungi correlate with their pathogenicity. Using gene knockouts and pathogenity assays in mice, we identify deacetylases with critical roles in virulence and protein translation elongation. Finally, through mutational analysis of deactylation motifs we find evidence of positive selection at specific acetylation motifs in fungal pathogens. These results shed new light on the pathogenicity regulation mechanisms underlying the evolution of fungal acetylomes.
Project description:The rate, timing, and mode of species dispersal is recognized as a key driver of the structure and function of communities of macroorganisms, and may be one ecological process that determines the diversity of microbiomes. Many previous studies have quantified the modes and mechanisms of bacterial motility using monocultures of a few model bacterial species. But most microbes live in multispecies microbial communities, where direct interactions between microbes may inhibit or facilitate dispersal through a number of physical (e.g., hydrodynamic) and biological (e.g., chemotaxis) mechanisms, which remain largely unexplored. Using cheese rinds as a model microbiome, we demonstrate that physical networks created by filamentous fungi can impact the extent of small-scale bacterial dispersal and can shape the composition of microbiomes. From the cheese rind of Saint Nectaire, we serendipitously observed the bacterium Serratia proteamaculans actively spreads on networks formed by the fungus Mucor. By experimentally recreating these pairwise interactions in the lab, we show that Serratia spreads on actively growing and previously established fungal networks. The extent of symbiotic dispersal is dependent on the fungal network: diffuse and fast-growing Mucor networks provide the greatest dispersal facilitation of the Serratia species, while dense and slow-growing Penicillium networks provide limited dispersal facilitation. Fungal-mediated dispersal occurs in closely related Serratia species isolated from other environments, suggesting that this bacterial-fungal interaction is widespread in nature. Both RNA-seq and transposon mutagenesis point to specific molecular mechanisms that play key roles in this bacterial-fungal interaction, including chitin utilization and flagellin biosynthesis. By manipulating the presence and type of fungal networks in multispecies communities, we provide the first evidence that fungal networks shape the composition of bacterial communities, with Mucor networks shifting experimental bacterial communities to complete dominance by motile Proteobacteria. Collectively, our work demonstrates that these strong biophysical interactions between bacterial and fungi can have community-level consequences and may be operating in many other microbiomes.
Project description:Within the last decades, invasive fungal infections have gained increasing significance. They are characterized by high mortality rates and are often caused Candida albicans and Aspergillus fumigatus. The increasing number of infections underlines the necessity for additional anti-fungal therapies, which require an extended knowledge of gene regulations during fungal infection. MicroRNAs are regulators of important cellular processes, including immune response. By analyzing their regulation and impact on target genes, novel therapeutic approaches may be developed. Here, we examine the role of microRNAs in human dendritic cells during fungal infections. Dendritic cells represent the bridge between the innate and the adaptive immune systems. Therefore, analysis of gene regulation of dendritic cells is of particular significance. By applying next-generation sequencing of small RNAs, we quantify microRNA expression in monocyte-derived dendritic cells after 6 and 12h of infection with C. albicans and A. fumigatus as well as treatment with LPS. We use two different tools and an online database to determine potential target genes. We identified 29 microRNAs that are differentially regulated after infection by the fungi or LPS. Two and five of them are specific for fungal infections after 6h and 12h, respectively. We further validated interactions of miR-132-5p and miR-212-5p with immunological relevant target genes, such as FKBP1B, KLF4, and SPN, on both RNA and protein level. Our results indicate a fine-tuning function of these microRNAs during fungal infections. Beyond that, we identified previously undiscovered microRNAs. We validated three novel microRNAs via qRT-PCR. A comparison with known microRNAs revealed possible relations with the miR-378 family and miR-1260a/b for two of them, while the third one features a unique sequence with no resemblance to known microRNAs. In summary, this study analyzes the effect of known microRNAs in dendritic cells during fungal infections and proposes novel microRNAs that could be experimentally verified.