Project description:Abstract From manuscript: Incidences of invasive pulmonary aspergillosis, an infection caused predominantly by Aspergillus fumigatus, have increased due to the growing number of immunocompromised individuals. While A. fumigatus is reliant upon deficiencies in the host to facilitate invasive disease, the distinct mechanisms that govern the host-pathogen interaction remain enigmatic, particularly in the context of distinct immune modulating therapies. To gain insights into these mechanisms, RNA-Seq technology was utilized to sequence RNA derived from lungs of 2 clinically relevant, but immunologically distinct murine models of IPA on days 2 and 3 post inoculation when infection is established and active disease present. Our findings identify notable differences in host gene expression between the chemotherapeutic and steroid models at the interface of immunity and metabolism. RT-qPCR verified model specific and nonspecific expression of 23 immune-associated genes. Deep sequencing facilitated identification of highly expressed fungal genes. We utilized sequence similarity and gene expression to categorize the A. fumigatus putative in vivo secretome. RT-qPCR suggests model specific gene expression for nine putative fungal secreted proteins. Our analysis identifies contrasting responses by the host and fungus from day 2 to 3 between the two models. These differences may help tailor the identification, development, and deployment of host- and/or fungal-targeted therapeutics.
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: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: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: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:Invasive aspergillosis (IA) is a devastating opportunistic infection and its treatment constitutes a considerable burden for the health care system. Immunocompromised patients are at an increased risk for IA, which is mainly caused by the species Aspergillus fumigatus. An early and reliable diagnosis is required to initiate the appropriate antifungal therapy. However, diagnostic sensitivity and accuracy still needs to be improved, which can be achieved at least partly by the definition of new biomarkers. Besides the direct detection of the pathogen by the current diagnostic methods, the analysis of the host response is a promising strategy towards this aim. Following this approach, we sought to identify new biomarkers for IA. For this purpose, we analyzed gene expression profiles of haematological patients and compared profiles of patients suffering from IA with non-IA patients. Based on microarray data, we applied a comprehensive feature selection using a random forest classifier. We identified the transcript coding for the S100 calcium-binding protein B (S100B) as a potential new biomarker for the diagnosis of IA. Considering the expression of this gene, we were able to classify samples from patients with IA with 82.3% sensitivity and 74.6% specificity. Moreover, we validated the expression of S100B in a real-time RT-PCR assay and we also found a down-regulation of S100B in A. fumigatus stimulated DCs. An influence on the IL1B and CXCL1 downstream levels was demonstrated by this S100B knockdown. In conclusion, this study covers an effective feature selection revealing a key regulator of the human immune response during IA. S100B may represent an additional diagnostic marker that in combination with the established techniques may improve the accuracy of IA diagnosis. The gene expression data of patients with invasive aspergillosis (IA) was compared to patients without IA. 23 samples of 8 IA patients, 13 samples from 7 unclassified patients and 1 patient with possible invasive fungal disease (IFD), and 9 control samples from 8 healthy donors were generated. Patients were classified according to the current EORTC/MSG criteria.
Project description:Rapidly and Reconditely Progressing Small Cell Lung Cancer with Invasive Pulmonary Aspergillosis: A Case Report and Literature Review
Project description:Proven invasive pulmonary aspergillosis in stem cell transplant recipient due to Aspergillus sublatus, a cryptic species of A. nidulans