Project description:SARS-CoV-2 infection results in impaired interferon response in severe COVID-19 patients. However, how SARS-CoV-2 interferes with host immune response is incompletely understood. Here, we sequenced small RNAs from SARS-CoV-2-infected human cells and identified a microRNA (miRNA) derived from a recently evolved region of the viral genome. We show that the virus-derived miRNA produces two miRNA isoforms in infected cells by the enzyme Dicer and they are loaded into Argonaute proteins. Moreover, the predominant miRNA isoform targets the 3´UTR of interferon-stimulated genes and represses their expression in a miRNA-like fashion. Finally, the two viral miRNA isoforms were detected in nasopharyngeal swabs from COVID-19 patients. We propose that SARS-CoV-2 can potentially employ a virus-derived miRNA to hijack the host miRNA machinery which can lead to evasion of the interferon-mediated immune response.
Project description:We recently reported the COVID-19-induced circulating leukocytes DNA methylation profile. Here, we hypothesized that some of these genes would persist differentially methylated after disease resolution. Fifteen participants previously hospitalized for SARS-CoV-2 infection were epityped one year after discharge. Of the 1505 acute illness-induced differentially methylated regions (DMRs) previously identified, we found 71 regions with persisted differentially methylated, with an average of 7 serial CpG positions per DMR. Sixty-four DMRs persisted hypermethylated, and 7 DMR persisted hypomethylated. These data are the first reported evidence that DNA methylation changes in circulating leukocytes endure long after recovery from acute illness.
Project description:Healthcare workers were recruited at St Bartholomew’s Hospital, London, UK in the week of lockdown in the United Kingdom (between 23rd and 31st March 2020). Participants underwent weekly evaluation using a questionnaire and biological sample collection (including serological assays) for up to 16 weeks when attending for work and self-declared as fit to attend work at each visit, with further follow up samples collected at 24 weeks. Blood RNA sequencing data was to be used to identify host-response biomarkers of early SARS-CoV-2 infection, to evaluate existing blood transcriptomic signatures of viral infection, and to describe the underlying biology during SARS-CoV-2 infection. This submission includes a total of 172 blood RNA samples from 99 participants. Of these, 114 samples (including 16 convalescent samples collected 6 months after infection) were obtained from 41 SARS-CoV-2 cases, with the remaining 58 from uninfected controls. Participants with available blood RNA samples who had PCR-confirmed SARS-CoV-2 infection during follow-up were included as ‘cases’. Those without evidence of SARS-CoV-2 infection on nasopharyngeal swabs and who remained seronegative by both Euroimmun anti S1 spike protein and Roche anti nucleocapsid protein throughout follow-up were included as uninfected controls. ‘Cases’ include all available RNA samples, including convalescent samples at week 24 of follow-up for a subset of participants. For uninfected controls, we included baseline samples only. Sample class denotes weekly interval to positive SARS-CoV-2 PCR; non-infected controls (NIC); convalescent samples (Conv)_.
Project description:Dysregulated immune responses contribute to the excessive and uncontrolled inflammation observed in severe COVID-19. However, how immunity to SARS-CoV-2 is induced and regulated remains unclear. Here we uncover a role of the complement system in the induction of innate and adaptive immunity to SARS-CoV-2. Complement rapidly opsonizes SARS-CoV-2 particles via the lectin pathway. Complement-opsonized SARS-CoV-2 efficiently induces type-I interferon and pro-inflammatory cytokine responses via activation of dendritic cells, which are inhibited by antibodies against the complement receptors (CR) 3 and 4. Serum from COVID-19 patients, or monoclonal antibodies against SARS-CoV-2, attenuate innate and adaptive immunity induced by complement-opsonized SARS-CoV-2. Blocking of CD32, the FcγRII antibody receptor of dendritic cells, restores complement-induced immunity. These results suggest that opsonization of SARS-CoV-2 by complement is involved in the induction of innate and adaptive immunity to SARS-CoV-2 in the acute phase of infection. Subsequent antibody responses limit inflammation and restore immune homeostasis. These findings suggest that dysregulation of the complement system and FcγRII signaling may contribute to severe COVID-19.
Project description:Viral pandemics pose an imminent threat to humanity. The ongoing COVID-19 pandemic, caused by the SARS-CoV-2 virus, requires the urgent development of anti-viral therapies. Because of its recent emergence, there is a paucity of information regarding viral behavior and host response following SARS-CoV-2 infection. Here, we offer an in-depth analysis of the host response to SARS-CoV-2 as it compares to other respiratory infections. Cell and animal models of SARS-CoV-2 infections, in addition to transcriptional profiling of a COVID-19 lung biopsy consistently revealed a unique and inappropriate inflammatory response defined by elevated chemokine expression in the absence of Type I and III interferons. Our identification of a muted transcriptional response to SARS-CoV-2 supports a model in which initial failure to rapidly respond to infection results in prolonged viral replication and an influx of proinflammatory cells that induce alveolar damage and manifest in COVID-19 lung pathology.
Project description:To explore the relationship between SARS-CoV-2 infection in different time before operation and postoperative main complications (mortality, main pulmonary and cardiovascular complications) 30 days after operation; To determine the best timing of surgery after SARS-CoV-2 infection.
Project description:HAE cultures were infected with SARS-CoV, SARS-dORF6 or SARS-BatSRBD and were directly compared to A/CA/04/2009 H1N1 influenza-infected cultures. Cell samples were collected at various hours post-infection for analysis. Time Points = 0, 12, 24, 36, 48, 60, 72, 84 and 96 hrs post-infection for SARS-CoV, SARS-dORF6 and SARS-BatSRBD. Time Points = 0, 6, 12, 18, 24, 36 and 48 hrs post-infection for H1N1. Done in triplicate or quadruplicate for RNA Triplicates/quadruplicates are defined as 3/4 different wells, plated at the same time and using the same cell stock for all replicates. Time matched mocks done in triplicate from same cell stock as rest of samples. Culture medium (the same as what the virus stock is in) will be used for the mock infections. Infection was done at an MOI of 2.
Project description:HAE cultures were infected with SARS-CoV, SARS-ddORF6 or SARS-BatSRBD and were directly compared to A/CA/04/2009 H1N1 influenza-infected cultures. Cell samples were collected at various hours post-infection for analysis. Time Points = 0, 12, 24, 36, 48, 60, 72, 84 and 96 hrs post-infection for SARS-CoV. Time Points = 0, 24, 48, 60, 72, 84 and 96 hrs post-infection forSARS-ddORF6 and SARS-BatSRBD. Time Points = 0, 6, 12, 18, 24, 36 and 48 hrs post-infection for H1N1. Done in triplicate/quadruplicate for RNA Triplicates/quadruplicates are defined as 3/4 different wells, plated at the same time and using the same cell stock for all replicates. Time matched mocks done in triplicate from same cell stock as rest of samples. Culture medium (the same as what the virus stock is in) will be used for the mock infections. Infection was done at an MOI of 2.
Project description:HAE cultures were infected with SARS-CoV, SARS-dORF6 or SARS-BatSRBD and were directly compared to A/CA/04/2009 H1N1 influenza-infected cultures. Cell samples were collected at various hours post-infection for analysis. Time Points = 0, 12, 24, 36, 48, 60, 72, 84 and 96 hrs post-infection for SARS-CoV, SARS-dORF6 and SARS-BatSRBD. Time Points = 0, 6, 12, 18, 24, 36 and 48 hrs post-infection for H1N1. Done in triplicate for RNA Triplicates are defined as 3 different wells, plated at the same time and using the same cell stock for all replicates. Time matched mocks done in triplicate from same cell stock as rest of samples. Culture medium (the same as what the virus stock is in) will be used for the mock infections. Infection was done at an MOI of 2 for SARS viruses and an MOI of 1 for H1N1.
Project description:The COVID-19 pandemic continues to have an unprecedented impact on societies and economies worldwide. There remains an ongoing need for high-performance SARS-CoV-2 tests which may be broadly deployed for infection monitoring. Here we report a highly sensitive single molecule array (Simoa) immunoassay in development for detection of SARS-CoV-2 nucleocapsid protein (N-protein) in venous and capillary blood and saliva. In all matrices in the studies conducted to date we observe >98% negative percent agreement and >90% positive percent agreement with molecular testing for days 1-7 in symptomatic, asymptomatic, and pre-symptomatic PCR+ individuals. N-protein load decreases as anti-SARS-CoV-2 spike-IgG increases, and N-protein levels correlate with RT-PCR Ct-values in saliva, and between matched saliva and capillary blood samples. This Simoa SARS-CoV-2 N-protein assay effectively detects SARS-CoV-2 infection via measurement of antigen levels in blood or saliva, using non-invasive, swab-independent collection methods, offering potential for at home and point of care sample collection.