Project description:Identification of SARS-CoV2 in cardiac tissue biopsy from a patient identified with COVID-19 in Quito, Ecuador - Raw sequence reads
Project description:SARS-CoV-2 can generate viral microRNAs (v-miRNAs) that target host gene expression. This study used small RNAseq to identify the v-miRNAs present in COVID-19 patients' nasopharyngeal swabs. The study identified a specific conserved v-miRNA sequence (CoV2-miR-O8) unique to SARS-CoV-2 that is highly present in COVID-19 patients' samples, interacts with Argonaute, and has features consistent with Dicer and Drosha generation. CoV2-miR-O8 is predicted to target specific human genes and can be detected by RTPCR assays in patients.
Project description:Syrian golden hamsters exhibit features of severe disease after SARS-CoV-2 challenge and are therefore useful models of COVID-19 pathogenesis and prevention with vaccines. Recent studies have shown that SARS-CoV-2 infection stimulates type I interferon, myeloid, and inflammatory signatures similar to human disease, and that weight loss can be prevented with vaccines. However, the impact of vaccination on transcriptional programs associated with COVID-19 pathogenesis and protective adaptive immune responses is unknown. Here we show that SARS-CoV-2 challenge in hamsters stimulates myeloid and inflammatory programs as well as signatures of complement and thrombosis associated with human COVID-19. Notably, single-dose immunization with Ad26.COV2.S, an adenovirus serotype 26 vector (Ad26)-based vaccine expressing a stabilized SARS-CoV-2 spike protein, prevents the upregulation of these pathways such that the gene expression profiles of vaccinated hamsters are comparable to uninfected animals. Furthermore, we validated the protective efficacy of the Ad26.COV2.S against proinflammatory pathways and coagulation cascade in rhesus macaques by proteomics. Finally, we show that Ad26.COV2.S vaccination induces T and B cell signatures that correlate with binding and neutralizing antibody responses. These data provide further insights into the mechanisms of Ad26.COV2.S based protection against severe COVID-19 in hamsters.
Project description:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus diseases 2019 (COVID-19) and broncho-alveolar inflammation (Merad and Martin, 2020). IL-9 induces airway inflammation and bronchial hyper responsiveness in respiratory viral illnesses and allergic inflammation (Temann et al., 1998). However, the role of IL-9 is not yet identified in SARS-CoV2 infection. Here we show that IL-9 promotes SARS-CoV2 infection and airway inflammation in K18-hACE2 transgenic (ACE2.Tg) mice, as IL-9 blockade reduces SARS-CoV2 infection and suppressed airway inflammation. Foxo1 is essential for the induction of IL-9 in helper T (Th) cells (Malik et al., 2017). While ACE2.Tg mice with Foxo1-deficiency in CD4+ T cells were performed to be resistant to SARS-CoV2 infection associated with reduced IL-9 production, exogenous IL-9 made Foxo1-deficient mice susceptible to SARS-CoV2 infection with increased airway inflammation. Collectively, we identify a mechanistic insight of IL-9-mediated regulation of antiviral and inflammatory pathways in SARS-CoV2 infection, and unravel a principle for the development of host-directed therapeutics to mitigate disease severity.
Project description:High-throughput sequencing of the miRNAs present in plasma of COVID-19 patients at an early stage of the disease including non-SARS-CoV2 infected patients. This study allowed us to identify and functionally characterize human miRNAs associated with a worse evolution of the disease and a greater mortality. Samples were collected at hospital entry or within the first days after hospitalization and before treatment with immunotherapy for IL6 (e.g. Tocilizumab), interferon beta, corticoids and ribavirin, among others. Plasma samples were obtained from peripheral blood extracted in EDTA tubes after centrifugation. Total RNA, including small RNAs, was isolated from 400μl of plasma with the miRNeasy Serum Plasma Advanced kit (Qiagen). RNA quality and quantity were evaluated by the Bioanalyzer 2100 with Agilent RNA 6000 Nano Kit.
Project description:Pathogenic mechanisms underlying severe SARS-CoV2 infection remain largely unelucidated. High-throughput sequencing technologies that capture genome and transcriptome information are key approaches to gain detailed mechanistic insights from infected cells. These techniques readily detect both pathogen and host-derived sequences, providing a means of studying host-pathogen interactions. Recent studies have reported the presence of host-virus chimeric (HVC) RNA in RNA-seq data from SARS-CoV2 infected cells and interpreted these findings as evidence of viral integration in the human genome as a pathogenic mechanism. Since SARS-CoV2 is a positive sense RNA virus that replicates in the cytoplasm it does not have a nuclear phase in its life cycle, so it is biologically unlikely to be in a location where splicing events could result in genome integration. Here, we investigated the biological authenticity of HVC events. In contrast to true biological events, e.g. mRNA splicing and genome rearrangement events, which generate reproducible chimeric sequencing fragments across different biological isolates, we found that HVC events across >100 RNA-seq libraries from patients with COVID-19 and SARS-CoV2 infected cell lines, were highly irreproducible. RNA-seq library preparation is inherently error-prone due to random template switching during reverse transcription of RNA to cDNA. By counting chimeric events observed when constructing an RNA-seq library from human RNA and spike-in RNA from an unrelated species, such as fruit-fly, we estimated that ~1% of RNA-seq reads are artifactually chimeric. In SARS-CoV2 RNA-seq we found that the frequency of HVC events were, in fact, no more frequent than this background “noise”. Finally, we developed a novel experimental approach to enrich SARS-CoV2 sequences from bulk RNA of infected cells. This method enriched viral sequences but did not enrich for HVC events, suggesting that the majority of HVC events are, in all likelihood, artifacts of library construction. In conclusion, our findings indicate that HVC events observed in RNA-sequencing libraries from SARS-CoV2 infected cells are extremely rare and are likely artifacts arising from either random template switching of reverse-transcriptase and/or sequence alignment errors. Therefore, the observed HVC events do not support SARS-CoV2 fusion to cellular genes and/or integration into human genomes.
Project description:Ad26.COV2.S has demonstrated durability and clinical efficacy against symptomatic COVID-19 in humans. In this study, we report the correlates of durability of humoral and cellular immune responses in 20 rhesus macaques immunized with single-shot Ad26.COV2.S and the immunogenicity of a booster shot at 8 to 10 months after the initial immunization. Ad26.COV2.S elicited durable binding and neutralizing antibodies as well as memory B cells and long-lived bone marrow plasma cells. Innate immune responses and bone marrow plasma cell responses correlated with durable antibody responses. After Ad26.COV2.S boost immunization, binding and neutralizing antibody responses against multiple SARS-CoV-2 variants increased 31- to 69-fold and 23- to 43-fold, respectively, compared with preboost concentrations. Antigen-specific B cell and T cell responses also increased substantially after the boost immunization. Boosting with a modified Ad26.COV2.S.351 vaccine expressing the SARS-CoV-2 spike protein from the beta variant led to largely comparable responses with slightly higher beta- and omicron-specific humoral immune responses. These data demonstrate that a late boost with Ad26.COV2.S or Ad26.COV2.S.351 resulted in a marked increase in humoral and cellular immune responses that were highly cross-reactive across multiple SARS-CoV-2 variants in rhesus macaques.
Project description:The goal of this study was to determine changes in the expression of genes in monoctic myleoid derived suppressor cells (M-MDSC) as a result of SARS CoV2 infection. The study aimed to investigate if M-MDSC are functionally active and inhibit T cell function in response to SARS CoV2 antigens 5 months after first detection of the virus. Methods: Peripheral blood mononuclear cells (PBMC) were collected from CoV2 (-) and CoV2 (+) donors (N=5 each group). M-MDSC were isolated by flow cytometry, and RNA extracted for RNA-seq studies. Filtering low quality reads and removal of the 3’ adapter sequences were performed using the Trim Galore tool. Reads were mapped to the latest version of the human genome (build hg38) using HISAT2. Mapped reads were counted against the human GENCODE annotation (v37) using HT-Seq. The EdgeR library in the R computing environment was used for quality control of the RNA-Seq data, and ComBat-seq method for correction of batch effects. Differential gene expression analysis was conducted using EdgeR. Pathway enrichment analysis was performed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) v6.8. Results: An average of 34 million reads per sample were acquired and mapped to the human genome (build hg38). After applying filtering criteria, 9,217 human genes were identified with the HISAT2 and HTSeq workflow. Differential expression analysis was performed between CoV2 (+) and CoV2 (-) samples using EdgeR. A total of 188 differentially expressed genes (DEGs) were identified with nominal p-value <0.05; of which 63 were up- and 125 downregulated in CoV2 (+) samples. A total of 12 DEGs were identified with false discovery rate corrected p-value <0.05, of which 2 were up- and 10 downregulated. Pathway enrichment analysis identified pathways involved in immune response and innate immune signaling. Conclusion: The study demonstrated that CoV2 infection modulated the expression of genes involved in immune response and innate immune signaling. Most of the genes remained downregulated even after 5 months of first detection of SARS CoV2.
Project description:Coronavirus disease 2019 (COVID-19) is the latest respiratory pandemic resulting from zoonotic transmission of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). Severe symptoms include viral pneumonia secondary to infection and inflammation of the lower respiratory tract, in some cases causing death. We developed primary human lung epithelial 5 infection models to understand responses of proximal and distal lung epithelium to SARS-CoV-2 infection. Differentiated air-liquid interface cultures of proximal airway epithelium and 3D organoid cultures of alveolar epithelium were readily infected by SARS-CoV-2 leading to an epithelial cell-autonomous proinflammatory response. We validated the efficacy of selected candidate COVID-19 drugs confirming that Remdesivir strongly suppressed viral 10 infection/replication. We provide a relevant platform for studying COVID-19 pathobiology and for rapid drug screening against SARS-CoV-2 and future emergent respiratory pathogens.