Project description:We studied the host transcriptional response to SARS-CoV-2 by performing metagenomic sequencing of upper airway samples in 234 patients with COVID-19 (n=93), other viral (n=100) or non-viral (n=41) acute respiratory illnesses (ARIs). Compared to other viral ARIs, COVID-19 was characterized by a diminished innate immune response, with reduced expression of genes involved in toll-like receptor and interleukin signaling, chemokine binding, neutrophil degranulation and interactions with lymphoid cells. Patients with COVID-19 also exhibited significantly reduced proportions of neutrophils, macrophages, and increased proportions of goblet, dendritic and B-cells, compared to other viral ARIs. Using machine learning, we built 27-, 10- and 3-gene classifiers that differentiated COVID-19 from other acute respiratory illnesses with AUCs of 0.981, 0.954 and 0.885, respectively. Classifier performance was stable at low viral loads, suggesting utility in settings where direct detection of viral nucleic acid may be unsuccessful. Taken together, our results illuminate unique aspects of the host transcriptional response to SARS-CoV-2 in comparison to other respiratory viruses and demonstrate the feasibility of COVID-19 diagnostics based on patient gene expression.
Project description:Severe COVID-19 can result in pneumonia and acute respiratory failure. Accumulation of mucus in the airways is a hall mark of the disease and can result in hypoxemia. Here, we show that quantitative proteome analysis of the sputum from severe COVID-19 patients reveal high levels of neutrophil extracellular trap(s) (NETs) components, which was confirmed by microscopy. Degrading pulmonary NETs using clinically approved aerosolized recombinant human DNase (rhDNase/Pulmozyme) improved pulmonary function, reversed hypoxemia, and aided in the rapid recovery of severely ill COVID-19 patients. Immunofluorescence and proteome analysis of sputum and blood plasma samples after treatment revealed a marked reduction of NETs and a set of statistically significant proteome changes that indicate local reduction of haemorrhage, plasma leakage and inflammation in the airways, and a reversion of the systemic inflammatory state in the blood plasma. Taken together, the results show that NETs contribute to acute respiratory failure in COVID-19 and that degrading NETs may reduce dependency on external high flow oxygen therapy. Targeting NETs may have significant therapeutic implications in COVID-19 disease and warrants further studies.
Project description:In the initial process of COVID-19, SARS-CoV-2 infects respiratory epithelial cells and then transfers to other organs via the blood vessels. It is believed that SARS-CoV-2 can pass the vascular wall by altering the endothelial barrier using an unknown mechanism. In this study, we investigated the effect of SARS-CoV-2 on the endothelial barrier using an airway-on-a-chip that mimics respiratory organs and found that SARS-CoV-2 produced from infected epithelial cells disrupts the barrier by decreasing Claudin-5 (CLDN5), a tight junction protein, and disrupting vascular endothelial cadherin (VE-cadherin)-mediated adherens junctions. Consistently, the gene and protein expression levels of CLDN5 in a COVID-19 patient’s lungs were decreased. CLDN5 overexpression or Fluvastatin treatment could rescue the SARS-CoV-2-induced respiratory endothelial barrier disruption. We therefore concluded that the downregulation of CLDN5 expression is a pivotal mechanism for SARS-CoV-2-induced endothelial barrier disruption in respiratory organs and that inducing CLDN5 expression is a novel therapeutic strategy against COVID-19.
Project description:Patients infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for the coronavirus disease 2019 (COVID-19), exhibit a wide spectrum of disease behavior. Since DNA methylation has been implicated in the regulation of viral infections and the immune system, we performed an epigenome- wide association study (EWAS) to identify candidate loci regulated by this epigenetic mark that could be involved in the onset of COVID-19 in patients without comorbidities.
Project description:In the initial process of COVID-19, SARS-CoV-2 infects respiratory epithelial cells and then transfers to other organs via the blood vessels. It is believed that SARS-CoV-2 can pass the vascular wall by altering the endothelial barrier using an unknown mechanism. In this study, we investigated the effect of SARS-CoV-2 on the endothelial barrier using an airway-on-a-chip that mimics respiratory organs and found that SARS-CoV-2 produced from infected epithelial cells disrupts the barrier by decreasing Claudin-5 (CLDN5), a tight junction protein, and disrupting vascular endothelial cadherin (VE-cadherin)-mediated adherens junctions. Consistently, the gene and protein expression levels of CLDN5 in a COVID-19 patient’s lungs were decreased. CLDN5 overexpression or Fluvastatin treatment could rescue the SARS-CoV-2-induced respiratory endothelial barrier disruption. We therefore concluded that the downregulation of CLDN5 expression is a pivotal mechanism for SARS-CoV-2-induced endothelial barrier disruption in respiratory organs and that inducing CLDN5 expression is a novel therapeutic strategy against COVID-19.
Project description:To unravel distinct pattern of metagenomic surveillance and respiratory microbiota between Mycoplasma pneumoniae (M. pneumoniae) P1-1 and P1-2 and explore the impact of COVID-19 pandemic on epidemiological features
Project description:Understanding the pathology of COVID-19 is a global research priority. Early evidence suggests that the microbiome may be playing a role in disease progression, yet current studies report contradictory results. Here, we examine potential confounders in COVID-19 microbiome studies by analyzing the upper respiratory tract microbiome in well-phenotyped COVID-19 patients and controls combining microbiome sequencing, viral load determination, and immunoprofiling. We found that time in the intensive care unit and the type of oxygen support explained the most variation within the upper respiratory tract microbiome, dwarfing (non-significant) effects from viral load, disease severity, and immune status. Specifically, mechanical ventilation was linked to altered community structure, lower species- and higher strain-level diversity, and significant shifts in oral taxa previously associated with COVID-19.
Project description:Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) impacts human health beyond acute infection. Myalgia and fatigue represent two of the most prevalent symptoms in post-COVID-19 syndrome. To determine the mechanisms underlying prolonged muscle symptoms, we characterized longitudinal histopathological and transcriptional changes of skeletal muscle after acute respiratory SARS-CoV-2 infection in a COVID-19 hamster model and compared them with respiratory influenza A virus (IAV) infection. Histopathological and bulk RNA sequencing analyses at 3, 30, and 60 days post infection (dpi) showed no evidence of direct viral invasion, inflammatory cell infiltration, or microthrombi in skeletal muscle, but myofiber atrophy was observed in the SARS-CoV-2 group at 60 dpi, accompanied by downregulation of myofiber genes, atrogenes, and cytoplasmic ribosomal protein genes, and upregulation of autophagy genes. There was persistent downregulation of genes involved in mitochondrial oxidative phosphorylation, fatty acid beta-oxidation, and tricarboxylic acid cycle in the SARS-CoV-2 but not the IAV group. Moreover, TNF-alpha/NF-kB and TGF-beta signaling pathways were differentially regulated in the SARS-CoV-2 group. Our findings suggest that persistent muscle symptoms after COVID-19 may be caused by muscle atrophy and energy metabolism suppression, and that the systemic inflammatory cytokine response may contribute, in part, to the skeletal muscle abnormalities.