Project description:Viruses are a constant threat to global health as shown by the current COVID-19 pandemic. Currently, lack of data underlying the biology of the interaction of the human host with SARS-CoV-2 virus is limiting effective therapeutic intervention. We introduce Viral-Track, a computational method that globally scans unmapped scRNA-seq data for the presence of viral RNA, enabling transcriptional cell sorting of infected versus bystander cells. We demonstrate the ability of Viral-Track to detect various viruses from multiple models of infection. Applying Viral-Track to Bronchoalveloar Lavage samples from severe and mild COVID-19 patients reveals a dramatic impact of the SARS-CoV-2 virus on the immune system of severe patients as compared to mild cases. The SARS-CoV-2 infection is mainly restricted to epithelial and macrophage subsets. In addition, Viral-Track detects in one of the severe patients an unexpected co-infection of the human MetaPneumoVirus, present mainly in monocytes and strongly dampening their type-I IFN-signaling.
Project description:Manuscript describes the daily dynamics of transcriptional responses in whole blood, from acute to convalescent phase, in severe and non-severe COVID-19 patients.
Project description:Severe COVID-19 may progress into acute respiratory distress syndrome (ARDS) with high mortality risk. Its exact pathological mechanism, therapeutic obstacles and the clinical sequelae are critical and unresolved issues. Here, we reported a representative COVID-19 induced ARDS case experienced initially stable, then suddenly deteriorating up to final respiratory failure courses, until his death despite of lung transplantation. His lung pathology showed necrosis of parenchymal tissues, extensive immune cell infiltration and lung fibrosis. Single-cell RNA sequencing revealed various immune cell populations were largely expanded in his lung, and manifested inflammatory/activated functions. We also showed that cell-crosstalk between lung macrophages and fibroblasts promoted pulmonary fibrosis through IL-1B and TGF-Β signaling pathways. Although SARS-CoV-2 RNA remained undetectable in his respiratory tract specimens including BALF at the later stage of his disease, the presence of SARS-CoV-2 was definitely confirmed in his lung tissues. Thus, this case indicates the pathological mechanism of severe COVID-19 includes pulmonary SARS-CoV-2 persistence, deranged inflammation and the extensive lung fibrosis which set the barriers for effective treatments and indicate potential health complications for severe COVID-19 patients.
Project description:Although most SARS-CoV-2-infected individuals experience mild COVID-19, some patients suffer from severe COVID-19, which is accompanied by acute respiratory distress syndrome and systemic inflammation. To identify factors driving severe progression of COVID-19, we performed single-cell RNA-seq using peripheral blood mononuclear cells (PBMCs) obtained from healthy donors, patients with mild or severe COVID-19, and patients with severe influenza. Patients with COVID-19 exhibited hyper-inflammatory signatures across all types of cells among PBMCs, particularly upregulation of the TNF/IL-1beta-driven inflammatory response as compared to severe influenza. In classical monocytes from patients with severe COVID-19, type I IFN response co-existed with the TNF/IL-1beta-driven inflammation, and this was not seen in patients with milder COVID-19 infection. Based on this, we propose that the type I IFN response exacerbates inflammation in patients with severe COVID-19 infection.
Project description:The causative organism, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), exhibits a wide spectrum of clinical manifestations in disease-ridden patients. Differences in the severity of COVID-19 ranges from asymptomatic infections and mild cases to the severe form, leading to acute respiratory distress syndrome (ARDS) and multiorgan failure with poor survival. MiRNAs can regulate various cellular processes, including proliferation, apoptosis, and differentiation, by binding to the 3′UTR of target mRNAs inducing their degradation, thus serving a fundamental role in post-transcriptional repression. Alterations of miRNA levels in the blood have been described in multiple inflammatory and infectious diseases, including SARS-related coronaviruses. We used microarrays to delineate the miRNAs and snoRNAs signature in the peripheral blood of severe COVID-19 cases (n=9), as compared to mild (n=10) and asymptomatic (n=10) patients, and identified differentially expressed transcripts in severe versus asymptomatic, and others in severe versus mild COVID-19 cases. A cohort of 29 male age-matched patients were selected. All patients were previously diagnosed with COVID-19 using TaqPath COVID-19 Combo Kit (Thermo Fisher Scientific, Waltham, Massachusetts), or Cobas SARS-CoV-2 Test (Roche Diagnostics, Rotkreuz, Switzerland), with a CT value < 30. Additional criterion for selection was age between 35 and 75 years. Participants were grouped into severe, mild and asymptomatic. Classifying severe cases was based on requirement of high-flow oxygen support and ICU admission (n=9). Whereas mild patients were identified based on symptoms and positive radiographic findings with pulmonary involvement (n=10). Patients with no clinical presentation were labelled as asymptomatic cases (n=10).
Project description:While critical for host defense, innate immune cells are also pathologic drivers of acute respiratory distress syndrome (ARDS). Innate immune dynamics during COVID-19 ARDS, compared to ARDS from other respiratory pathogens, is unclear. Moreover, mechanisms underlying beneficial effects of dexamethasone during severe COVID-19 remain elusive. Using scRNA-seq and plasma proteomics, we discovered that compared to bacterial ARDS, COVID-19 was associated with expansion of distinct neutrophil states characterized by interferon (IFN) and prostaglandin (PG) signalling. Dexamethasone during severe COVID-19 depleted circulating neutrophils, altered IFNactive neutrophils, downregulated interferon-stimulated gene, and activated IL1R2+ve neutrophils. Dexamethasone also expanded immunosuppressive immature neutrophils and remodeled cellular interactions by changing neutrophils from information receivers into information providers. Male patients had higher proportions of IFNactive neutrophils, preferential steroid-induced immature neutrophil expansion, and possibly different effects on outcome. Our single-cell atlas (www.biernaskielab.ca/COVID_neutrophil) defines COVID-19-enriched neutrophil states and molecular mechanisms of dexamethasone action to develop targeted immunotherapies for severe COVID-19.
Project description:In order to identify differentially abundant proteins, human plasma samples from COVID-19 patients with either a mild or moderate (MM) or a critical or severe (CS) disease course from acute phase of infection were analyzed on antibody microarrays 998 different proteins by 1,425 antibodies.
Project description:The objective of this experiment was to compare the transcriptomic profile (NanoString platform) of peripheral blood mononuclear cells (PBMCs) from COVID-19 patients with mild disease, and patients with severe COVID-19 with and without dexamethasone treatment, and healthy controls. We analyzed PBMCs from 4 mild COVID patients, 3 severe COVID patients,4 severe COVID patients treated with dexamethasone, and 5 healthy controls
Project description:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the ensuing COVID-19 pandemic have caused ∼40 million cases and over 648,000 deaths in the United States alone. Troubling disparities in COVID-19-associated mortality emerged early, with nearly 70% of deaths confined to Black/African-American (AA) patients in some areas, yet targeted studies within this demographic are scant. Multi-omics single-cell analyses of immune profiles from airways and matching blood samples of Black/AA patients revealed low viral load, yet pronounced and persistent pulmonary neutrophilia with advanced features of cytokine release syndrome and acute respiratory distress syndrome (ARDS), including exacerbated production of IL-8, IL-1β, IL-6, and CCL3/4 along with elevated levels of neutrophil elastase and myeloperoxidase. Circulating S100A12+/IFITM2+ mature neutrophils are recruited via the IL-8/CXCR2 axis, which emerges as a potential therapeutic target to reduce pathogenic neutrophilia and constrain ARDS in severe COVID-19.