Project description:CX3CR1pos monocytes are mobilized upon infection and undergo monocyte-to-macrophage transition in inflamed tissues. Using scRNA-seq of CD11c+ cells from bronchoalveolar lavage fluid (BALF) infected with IAV (PR/8, H1N1 ,we demonstrate that, during severe viral pneumonia, bone marrow-derived macrophages (BMDM) pass co-ordinated trajectories of pro-inflammatory-to-tissue-healing phenotypes, before differentiating into tissue-resident alveolar macrophages, that retain a long-term tissue-protective phenotype.
Project description:In dogs, a species for which markers of cell populations are often limiting, we sought to evaluate in an unbiased way the heterogeneity of cell subpopulations in the bronchoalveolar lavage fluid of healthy dogs, by single-cell RNA-sequencing.
Project description:The study is intended to find if correlation exists between the abundance of bacterial gene for pyruvate ferredoxin oxidoreductase (PFOR) and short-chain fatty acids concentration in bronchoalveolar lavage fluid from patients with HIV-Associated Bacterial Pneumonia.
Project description:Some patients infected with Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) develop severe pneumonia and the acute respiratory distress syndrome (ARDS). Distinct clinical features in these patients have led to speculation that the immune response to virus in the SARS-CoV-2-infected alveolus differs from other types of pneumonia. We collected bronchoalveolar lavage fluid samples from 88 patients with SARS-CoV-2-induced respiratory failure and 211 patients with known or suspected pneumonia from other pathogens and subjected them to flow cytometry and bulk transcriptomic profiling. We performed single-cell RNA-seq on 10 bronchoalveolar lavage fluid samples collected from patients with severe COVID-19 within 48 hours of intubation. In the majority of patients with SARS-CoV-2 infection, the alveolar space was persistently enriched in T cells and monocytes. Bulk and single-cell transcriptomic profiling suggested that SARS-CoV-2 infects alveolar macrophages, which in turn respond by producing T cell chemoattractants. These T cells produce interferon-gamma to induce inflammatory cytokine release from alveolar macrophages and further promote T cell activation. Collectively, our results suggest that SARS-CoV-2 causes a slowly-unfolding, spatially-limited alveolitis in which alveolar macrophages harboring SARS-CoV-2 and T cells form a positive feedback loop that drives persistent alveolar inflammation.
Project description:Many lung diseases remain understudied due to a lack of experimental models. Lung organoids, which consist of self-organizing epithelial cells, provide versatile in vitro models for normal and abnormal biology, drug screening, gene editing, and personalized therapeutics. However, human organoids are generally derived from lung tissue, which is not commonly obtained and represents only a small fraction of lung pathologies. Induced pluripotent stem cells have provided an important alternative but require complex manipulation. Recently, one study reported airway organoids from bronchoalveolar lavage (BAL) fluid, though sample sizes and characterization were limited. Here, we demonstrate robust establishment of airway organoids from a variety of human BAL samples and show that these organoids consist predominantly of basal cells plus differentiated airway cell types including secretory, ciliated, KRT13+ “hillock,” and ionocyte cells. Furthermore, we report the development of BAL-derived alveolar organoids comprised of alveolar type 2 (AT2) cells. These techniques significantly expand the scope of lung diseases that can be studied using safely accessible primary human cells.