Project description:Community-acquired pneumonia is a widespread disease with significant morbidity and mortality. Alveolar macrophages are tissue-resident lung cells that play a crucial role in innate immunity against bacteria causing pneumonia. We hypothesized that alveolar macrophages display adaptive characteristics after resolution of bacterial pneumonia. We studied mice one to six months after self-limiting lung infection due to Streptococcus pneumoniae, the most common cause of bacterial pneumonia. Among the myeloid cells recovered from the lung, only alveolar macrophages showed long-term modifications of their surface marker phenotype. The remodeling of alveolar macrophages was: (i) long-lasting (still observed 6 months post infection), (ii) regionally localized (only observed in the affected lobe after lobar pneumonia), and (iii) associated with a macrophage-dependent enhanced lung protection to another pneumococcal serotype. Metabolomic and transcriptomic profiling revealed that alveolar macrophages of mice which recovered from pneumonia had new baseline activities and altered responses to infection. Thus, the enhanced lung protection after mild and self-limiting respiratory infection includes a profound remodeling of alveolar macrophages that is long-lasting, compartmentalized, and manifest across surface receptors, metabolites, and both resting and stimulated transcriptomes. We used microarrays to detail the global program of gene expression for mouse alveolar macrophages sorted from lungs that were naïve or infected more than a month previously, at rest and during an acute (4-hour) infection.
Project description:BALF and plasma proteomic profiling from the Clinical Response in Pneumonia Therapy (SCRIPT) study which aims to improve treatment strategies for patients with severe pneumonia. The samples were obtained during the early stages of the COVID-19 pandemic (June 15th, 2018 - JulClinical Response in Pneumonia Therapy (SCRIPT) study which aims to improve treatment strategies for patients with severe pneumonia. The samples were obtained during the early stages of the COVID-19 pandemic (June 15th, 2018 - July 6th, 2020) and included patients facing respiratory failure requiring mechanical ventilation in the intensive care unit (ICU).
Project description:Cellular senescence is a complex multifactorial biological phenomenon that plays essential roles in aging, and aging-related diseases. During this process, the senescent cells undergo gene expression altering and chromatin structure remodeling. However, studies on the epigenetic landscape of senescence using integrated multi-omics approaches are limited. In this research, we performed ATAC-seq, RNA-seq, and ChIP-seq on different senescent types to reveal the landscape of senescence and identify the prime regulatory elements.
Project description:Rationale: Patients in the intensive care unit (ICU) are frequently exposed to unnecessary antibiotics. Markers of the host response to infection may aid pneumonia diagnosis and avoid antibiotic-induced complications. Objective: To assess the host response to suspected bacterial pneumonia through assessment of alveolar neutrophilia and transcriptomic profiling of alveolar macrophages. Methods: We determined the test characteristics of BAL neutrophilia for the diagnosis of bacterial pneumonia in 3 cohorts of mechanically ventilated patients. In one cohort, we also isolated alveolar macrophages from BAL fluid and used the transcriptome to identify signatures of bacterial pneumonia. Finally, we developed a humanized mouse model of Pseudomonas aeruginosa pneumonia to determine if pathogen-specific signatures can be identified in human alveolar macrophages. Measurements and Main Results: BAL neutrophilia was highly sensitive for bacterial pneumonia in both the retrospective (N = 851) and validation cohorts (N = 76 and N = 79) with a negative predictive value of over 90% when BAL neutrophil percentage was less than 50%. A transcriptional signature of bacterial pneumonia was present in both resident and recruited macrophages. Gene signatures from both cell types identified patients with bacterial pneumonia with test characteristics similar to BAL neutrophilia. Conclusions: A BAL neutrophil percentage of less than 50% is highly sensitive for bacterial pneumonia. Informative transcriptomic signatures can be generated from BAL fluid obtained during routine clinical care in the ICU. The identification of novel host response biomarkers is a promising approach to aid the diagnosis and treatment of pneumonia.
Project description:Pseudomonas aeruginosa (P. aeruginosa) can cause severe acute infections, including pneumonia and sepsis, and also cause chronic infections commonly in patients with structural respiratory diseases. However, the molecular and pathophysiological mechanisms of P. aeruginosa respiratory infection are largely unknown. Here, we profiled performed to assay for transposase-accessible chromatin using sequencing (ATAC-seq), transcriptomics, and quantitative mass spectrometry-based proteomics and ubiquitin-proteomics in P. aeruginosa-infected lung tissues for multi-omics analysis, while ATAC-seq and transcriptomics were also examined in P. aeruginosa-infected mouse macrophages. To find the pivotal transcription factors that are likely involved in host immune defense, we integrally investigated systematic changes in chromatin accessibility and gene expression in P. aeruginosa-infected lung tissues combined with proteomics and ubiquitin-proteomics studies. We discovered that Stat1 and Stat3 were altered in various omics and found similar results in mouse alveolar macrophages. Taken together, these findings indicate that these crucial transcription factors and their downstream signaling molecules play a critical role in the mobilization of host immune response against P. aeruginosa infection and may serve as potential targets for bacterial infections and inflammatory diseases, as well as provide clear insights and resources for using integrative histological analyses.