Time course RNA-Seq analysis of wildtype and Nlrx1 deficient bone marrow derived monocytoid dendritic cells indicate decision tree in response to A. fumigatus viable conidia
Ontology highlight
ABSTRACT: Aspergillus fumigatus is an opportunistic fungal pathogen of the respiratory system that may cause invasive infection or an allergic response. Monocytoid dendritic cells (moDCs) are a known recruited cell population during fungal colonization and are believed to be a critical player in balancing innate versus adaptive immune responses. We conducted an RNA-Seq time course analysis of moDCs challenged against A. fumigatus, to gain an appreciation of gene expression changes. We concurrently utilized Nlrx1 deficient moDCs as we have recently shown the importance of Nlrx1 during invasive pulmonary aspergillosis and shown the absence of Nlrx1 results in a robust shift towards a detrimental Th2 response. Our findings suggest a decision tree by moDCs in response to A. fumigatus viable conidia that is absent in Nlrx1-/- moDCs.
Project description:Aspergillus fumigatus is an opportunistic fungal pathogen of the respiratory system that may cause invasive infection or an allergic response. Bronchial airway epithelial cells compromise the most abundant cell type of the pulmonary-air interface. Our recent findings suggest loss of Nlrx1 by BEAS-2B airway epithelial cells result in a hyper inflammatory response as well as decreased conidial processing. We challenged wildtype Nlrx1 deficient BEAS-2B cells with viable A. fumigatus AF293 conidia to identify early response differentially expressed genes and pathways between the two cell populations.
Project description:Amphotericin B (AMB) is the most widely used polyene antifungal drug for the treatment of systemic fungal infections including invasive aspergillosis. We aimed to understand molecular targets of AMB in Aspergillus fumigatus (Afu) by genomic approaches. Amphotericin B (AMB) is the most widely used polyene antifungal drug for the treatment of systemic fungal infections including invasive aspergillosis. We aimed to understand molecular targets of AMB in Aspergillus fumigatus (Afu) by microarray and proteomic methods. Keywords: Aspergillus fumigatus treated with amphotericin B for 24 hours Experiment was performed in dye swap manner from two different biological replicates
Project description:In lung diseases caused by the major mould pathogen Aspergillus fumigatus the pulmonary epithelium is destroyed by invasive growth of fungal hyphae, a process thought to require fungal proteases. Here we show that the A. fumigatus pH-responsive transcription factor PacC governs expression of secreted proteases during invasive lung infections and is required for epithelial invasion and pathogenicity. In addition, A. fumigatus ΔpacC mutants aberrantly remodel the fungal cell wall during infection. This study defines distinct PacC-mediated mechanisms of host damage during pulmonary aspergillosis. ch1: treatment protocol
Project description:Amphotericin B (AMB) is the most widely used polyene antifungal drug for the treatment of systemic fungal infections including invasive aspergillosis. We aimed to understand molecular targets of AMB in Aspergillus fumigatus (Afu) by genomic approaches. Keywords: Aspergillus fumigatus treated with amphotericin B for 24 hours
Project description:In lung diseases caused by the major mould pathogen Aspergillus fumigatus the pulmonary epithelium is destroyed by invasive growth of fungal hyphae, a process thought to require fungal proteases. Here we show that the A. fumigatus pH-responsive transcription factor PacC governs expression of secreted proteases during invasive lung infections and is required for epithelial invasion and pathogenicity. In addition, A. fumigatus M-NM-^TpacC mutants aberrantly remodel the fungal cell wall during infection. This study defines distinct PacC-mediated mechanisms of host damage during pulmonary aspergillosis. ch1: treatment protocol Temporal transcriptional profiling of ATCC46645 strain and isogenic M-NM-^TpacC Aspergillus fumigatus mutant during murine infection
Project description:Aspergillus fumigatus is an important human fungal pathogen and its conidia are constantly inhaled by humans. In immunocompromised individuals, conidia can grow out as hyphae that damage lung epithelium. The resulting invasive aspergillosis is associated with devastating mortality rates. Since infection is a race between the innate immune system and the outgrowth of A. fumigatus conidia, we use dynamic optimization to obtain insight into the recruitment and depletion of alveolar macrophages and neutrophils. We illustrate by modeling the active, but so far neglected, major role of alveolar epithelial cells in phagocytosis and cytokine release as well as the importance of fungal growth states for virulence.
Hence, we discovered that germination speed is a key virulence trait of fungal pathogens due to the vulnerability of conidia against host defense. We proved this by linking measured germination kinetics of four Aspergillus spp. with their cytotoxicity against epithelial cells in silico and in vitro.Furthermore, we could reveal by modeling and ex vivo measurements, that epithelial cells are not only important phagocytes to clear conidia, but also potent mediators of cytokine release.
In conclusion, our findings illustrate an underestimated role of epithelial cells in invasive aspergillosis. Further, our model affirms the importance of neutrophils and underlines that the role of macrophages in invasive aspergillosis remains elusive.
We expect that our model will contribute to improvement of treatment protocols by focusing on
the critical components of immune response to fungi but also fungal virulence.
Project description:The response of AM transcription to exposure to conidia is expected to provide information about the mechanism by which these cells prevent conidial germination and therefore invasive aspergillosis. Experiment Overall Design: Conidia from A. fumigatus or polystyrene beads were instilled into lungs of C57Bl/6 or gp91phox-/- mice to test the response of AM in a normal and immune compromised host to determine if different responses contributed to increased susceptibility of invasive aspergillosis. Following in vivo incubation for 0, 2, or 4 hours, AM RNA was collected and prepared for hybridization to mouse Affymetrix GeneChip arrays.
Project description:The cells of the airway epithelium play critical roles in host defense to inhaled irritants, and in asthma pathogenesis. These cells are constantly exposed to conidiospores of the ubiquitous mould Aspergillus fumigatus, which are small enough to reach the alveoli. This exposure is asymptomatic in most individuals but can be associated with a spectrum of diseases ranging from asthma and allergic bronchopulmonary aspergillosis to aspergilloma and invasive aspergillosis. Airway epithelial cells have been shown to internalize A. fumigatus conidiospores in vitro, but the implications of this process for pathogenesis remain unclear. We have developed a cell culture model for this interaction using the 16HBE cell line and a transgenic A. fumigatus strain expressing green fluorescent protein. The transcriptional profiles of A. fumigatus conidiospores incubated in the presence or absence of human cells were compared, revealing significant changes in fungal gene expression in response to conidial interaction with cells.
Project description:The cells of the airway epithelium play critical roles in host defense to inhaled irritants, and in asthma pathogenesis. These cells are constantly exposed to conidiospores of the ubiquitous mould Aspergillus fumigatus, which are small enough to reach the alveoli. This exposure is asymptomatic in most individuals but can be associated with a spectrum of diseases ranging from asthma and allergic bronchopulmonary aspergillosis to aspergilloma and invasive aspergillosis. Airway epithelial cells have been shown to internalize A. fumigatus conidiospores in vitro, but the implications of this process for pathogenesis remain unclear. We have developed a cell culture model for this interaction using the 16HBE cell line and a transgenic A. fumigatus strain expressing green fluorescent protein. The transcriptional profiles of A. fumigatus conidiospores incubated in the presence or absence of human cells were compared, revealing significant changes in fungal gene expression in response to conidial interaction with cells. Gene expression levels were investigated in A. fumigatus conidiospores incubated in the presence or absence of 16HBE cells for 6 hours. Four independent samples were analysed for each of these conditions, using JCVI PFGRC Aspergillus fumigatus Version 3 microarrays, with a dye-swap experimental design.
Project description:We examined the antifungal activity of artemisinin against Aspergillus fumigatus (A. fumigatus), a pathogenic filamentous fungus responsible for allergic and invasive aspergillosis in humans and analyzed transcript profiles of the fungus on exposure to Artemisinin. A. fumigatus spores were cultured for 48 h and then treated with artemisinin (at MIC50 concentration) or solvent control (DMSO) for 3 h to study its transcriptomic profiles.