Project description:Proven invasive pulmonary aspergillosis in stem cell transplant recipient due to Aspergillus sublatus, a cryptic species of A. nidulans
Project description:Comprehensive proteomic analysis of the protein expression landscape of bronchoalveolar lavage fluid during invasive pulmonary aspergillosis in murine and human samples. 38 murine BALF samples (10 Aspergillus fumigatus infected mice without immunosuppression and without invasive pulmonary aspergillosis (IPA), 19 immunosuppressed and infected mice with IPA and 9 immunosuppressed animals without infection) were analysed for their global protein expression. In addition, 54 human BALF specimen from patients with probable IPA (23 samples), proven IPA (4 cases) and 27 control samples from patients with unrelated pulmonary diseases were analysed for their global protein composition. Host responses and Aspergillus fumigatus-specific proteins detectable in BALF were studied.
Project description:Aspergillosis covers a range of infections cause by Aspergillus species, and in many cases can be life threatening. Individuals with weakened immune systems are particularly at risk. Dendritic cells were derived from patients with allergic brochopulmonary aspergillosis (ABPA), chronic cavitary pulmonary aspergillosis (CCPA), and asthma, as well as from healthy donors. Each sample was split in two, and one sample from each pair was cultured with Aspergillus fumigatus. RNA-sequencing was used to assess transcriptional changes in the human cells in response to pathogen challenge. Many genes known to be important in immunity were found to exhibit differential expression after fungal challenge between healthy and diseased individuals, including chemokines and C-type lectins.
Project description:Despite available diagnostic tests and recent advances, diagnosis of pulmonary invasive aspergillosis (IPA) remains challenging. By undertaking a longitudinal case-control study, we explored the possibility to identify novel non-invasive human biomarkers candidates for IPA in patients post allogeneic stem cell transplantation (alloSCT). Using both RNA-sequencing and immunoassays, we investigated 66 blood samples of 3 probable IPA cases and 3 matched controls without Aspergillus infection. Selected potential biomarker candidates were evaluated further in additional alloSCT (n=23) and patients suffering from COVID-19-associated pulmonary aspergillosis (CAPA) and their appropriate control patients (n=65). Profiling analysis suggested LGALS2, MMP1 and caspase-3 as potential biomarker candidates indicating IPA in investigated alloSCT patients. Significant differences in IL-8 and caspase-3 levels were observed among CAPA patients compared to control patients. Given our conceptual work we demonstrate the value of seeking human IPA indicating biomarkers, which together with already established fungal biomarkers potentially improve the accuracy of IPA diagnostic.
Project description:To assess whether transcriptional differences exist in the epithelial tissue and the inflammatory infiltrate of invasive Aspergillus tracheobronchitis in patients with severe influenza or severe COVID-19, we performed GeoMx spatial transcriptomics on four biopsy samples in total: two of patients with influenza-associated pulmonary aspergillosis (IAPA) and two of patients with COVID-19-associated pulmonary aspergillosis (CAPA). Several regions of interest (ROIs) were delineated in each biopsy sample, and transcriptomic data was derived of each of these ROIs using GeoMx with a whole transcriptome atlas with SARS-CoV-2 spike-in.
Project description:Aspergillus fumigatus is the most important pulmonary fungal pathogen and is able to cause several diseases collectively called aspergillosis. Conidia is the most important infection structure making the initial contact with the human host. Here, we used a phylogenomic approach comparing proteins present in the A. fumigatus conidial surface, two closely related non-pathogenic species A. fischeri and A. oerlinghausenensis, and the far-related pathogenic A. lentulus. We were able to identify 62 proteins specifically expressed on A. fumigatus conidial surface. We deleted 42 of the encoding-genes and observed that many of them have altered susceptibility to macrophage killing, penetration and damage to epithelial cells, and cytokine production. We demonstrated that one of these genes encoding a glycosylasparaginase is modulating IL-1β levels and is important for the infection in an immunocompetent murine model. Our results provide opportunities for characterizing A. fumigatus effectors important for evasion and modulation of the immune response.
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:Treatment of post-transplant patients with immunosuppressive drugs targeting the calcineurin-NFAT pathway, such as Cyclosporine A or Tacrolimus, are commonly associated with a higher incidence of opportunistic infections, such as Aspergillus fumigatus, which can lead to severe life-threating conditions. A component of the A. fumigatus cell wall, β-glucan, is recognized by dendritic cells via the Dectin-1 receptor, triggering downstream signaling that leads to calcineurin-NFAT binding, NFAT translocation, and transcription of NFAT-regulated genes. Here, we address the question of whether calcineurin signaling in CD11c-expressing cells, such as DCs, has a specific role in the innate control of A. fumigatus. Impairment of calcineurin in CD11c-expressing cells (CD11ccrecnb1loxP) significantly increased susceptibility to systemic A. fumigatus infection and to intranasal infection in irradiated mice undergoing bone marrow transplant. Global expression profiling of bone marrow-derived DCs identified calcineurin-regulated processes in the immune response to infection, including expression of pentraxin-3, an important anti-fungal defense protein. These results suggest that calcineurin inhibition directly impairs important immunoprotective functions of myeloid cells, as shown by the higher susceptibility of CD11ccrecnbloxP mice in models of systemic and invasive pulmonary aspergillosis, including after allogeneic bone marrow transplantation. These findings are relevant to the clinical management of transplant patients with severe Aspergillus infections.
Project description:Eosinophilia is associated with various persisting inflammatory diseases and often coincides with chronic fungal infections or fungal allergy as in case of allergic bronchopulmonary aspergillosis (ABPA). However, the interactions between eosinophils and fungal pathogen leading to release of inflammatory mediators from eosinophils are poorly understood. Therefore, we established a co-culture system of mouse bone marrow derived eosinophils (BMDE) with Aspergillus fumigatus (Af) that we used in part to analyse transcriptional regulation induced by Af.
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
