Deciphering COVID-19 host transcriptomic complexity and variations for therapeutic discovery against new variants
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ABSTRACT: COVID-19 has infected 244 million people globally and evolved several variants with higher infectivity. Drug repurposing could be an efficient and timely means of drug discovery for the pandemic. To date, more than two hundred repurposed SARS-CoV-2 inhibitors have been reported but with moderate efficacy or acute toxicity. Thus, there is a great need to find new effective candidates against SARS-CoV-2, especially the new variants, with good safety profiles. We analyzed 17 hundred published host RNA-seq samples of SARS/MERS/SARS-CoV-2 infection derived from pre-clinical models or patients, together with the reported coronavirus inhibitors to summarize a robust coronavirus-induced host gene expression change signature, which captured biological processes involved in host cell machinery hijacking and immune evasion. Then we searched for drugs potently reversing the infection signature and discovered IMD-0354 as a promising candidate with nanomolar IC50 against SARS-CoV-2 and 6 variants, showing a wide therapeutic window of more than 100-fold. The RNA-seq of IMD-0354 treated cells infected with SARS-CoV-2 reaved that this drug could stimulate type I interferon antiviral response, inhibit viral entry and down-regulate hijacked proteins. This work demonstrated the power of biological big data and the efficiency of a system-based drug discovery approach, which can be used in future pandemic.
Project description:The ongoing SARS-CoV-2 pandemic has devastated the global economy and claimed more than one million lives, presenting an urgent global health crisis. To identify host factors required for infection by SARS-CoV-2 and seasonal coronaviruses, we designed a focused high-coverage CRISPR-Cas9 library targeting 332 members of a recently published SARS-CoV-2 protein interactome. We leveraged the compact nature of this library to systematically screen SARS-CoV-2 at two physiologically relevant temperatures (33 ºC and 37 ºC) along with three related coronaviruses (HCoV-229E, HCoV-NL63, and HCoV-OC43), allowing us to probe this interactome at a much higher resolution relative to genome scale studies. This approach yielded several new insights, including unexpected virus-specific differences in Rab GTPase requirements and GPI anchor biosynthesis, as well as identification of multiple pan-coronavirus factors involved in cholesterol homeostasis. This coronavirus essentiality catalog could inform ongoing drug development efforts aimed at intercepting and treating COVID-19, and help prepare for future coronavirus outbreaks.
Project description:The ongoing pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), necessitates strategies to identify prophylactic and therapeutic drug candidates for rapid clinical deployment. Here we describe a screening pipeline for the discovery of efficacious SARS-CoV-2 inhibitors. Two high-throughput, high-content imaging infection assays (one using HeLa cells expressing SARS-CoV-2 receptor ACE2 and the other using lung epithelial Calu-3 cells) were developed and used to screen ReFRAME, a best-in-class drug repurposing library. Among the promising hits, the antivirals nelfinavir and the parent of prodrug MK-4482 had most favorable in vitro activity, pharmacokinetic and human safety profiles, and both reduced SARS-CoV-2 replication in an orthogonal human differentiated primary cell model. However, only MK-4482 effectively blocked SARS-CoV-2 infection in a hamster model, likely due to inadequate plasma exposure of nelfinavir.
Project description:Diverse severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants have emerged since the beginning of COVID-19 pandemic. We investigated the immunological and pathological characteristics of SARS-CoV-2 beta variant of concern (VOC) compared to the ancestral strain. To investigate a broad spectrum of immunological responses and to determine the underlying mechanisms of differentially expressed cytokines, we analyzed the whole transcriptome of lung homogenates from SARS-CoV-2 ancestral strain- and beta variant-infected mice at 4 and 6 dpi.
Project description:Abstract: The COVID-19 (Coronavirus disease-2019) pandemic, caused by the SARS-CoV-2 coronavirus, has highlighted emergent viruses as significant threats to public health and the global economy. SARS-CoV-2 is closely related to the more lethal but less transmissible coronaviruses SARS-CoV-1 and MERS-CoV. Here, we have carried out comparative viral-human protein-protein interaction and viral protein localization analysis for all three viruses. We find that proteins often do not change localization across viruses but their sequence divergence dictates differences in host interactions. Functional genetic screening identified host factors that functionally impinge on coronavirus proliferation, including Tom70, a mitochondrial chaperone protein that interacts with both SARS-CoV-1 and SARS-CoV-2 Orf9b, an interaction we structurally characterized using cryoEM. Combining genetically validated host factors with both COVID-19 patient genetic data and medical billing records identified important molecular mechanisms (IL-17 regulation) and drug treatments (sigma-1 receptor ligands) that merit further molecular and clinical study.
Project description:We performed genome-wide CRISPR KO screens in human Huh7.5.1 cells to select for mutations that render host cells resistant to viral infection by SARS-CoV-2, human coronavirus 229E and OC43.
Project description:The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been linked to a wide range of neurological symptoms. In this study, the impact of SARS-CoV-2 infection on neuropsychiatric disorders in mice was investigated. To elucidate the role of SARS-CoV-2 infection in behavioral changes, we utilized a highly virulent mouse-adapted SARS-CoV-2 strain (SARS2-N501YMA30) to infect young C57BL/6 mice.
Project description:Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), a global pandemic characterized by respiratory illness and an exaggerated immune response. Age (>60 years) is a significant risk factor for developing severe COVID-19. However, the underlying mechanisms of how aging impacts SARS-CoV-2 infection and the host response are largely unknown. Therefore, we performed an in vitro study to characterize the host response to SARS-CoV-2 infection using primary human bronchial epithelial cells from donors >67 years of age differentiated on air-liquid interface culture. We demonstrate that SARS-CoV-2 infection leads to early induction of a proinflammatory response and a delayed interferon response. In addition, we observe changes in genes and pathways associated with cell death and senescence throughout infection. In summary, our study provides important insights into the temporal kinetics of the airway epithelial innate immune response to SARS-CoV-2 in older individuals.
Project description:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease (COVID-19) in humans, which may be lethal. In this study, we used a comparative transcriptomics approach to investigate the effects of SARS-CoV-2 infection on the host mRNA and sRNA expression programs in two primate cell lines. Upon infection, we observed global changes in host gene expression and differential expression of dozens of host miRNAs, many with known links to viral infection and immune response. Unexpectedly, we also discovered an expanded landscape of more than a hundred SARS-CoV-2-derived small viral RNAs (svRNAs), predicted to interact with differentially expressed host mRNAs and miRNAs. svRNAs are derived from distinct regions of the viral genome and sequence signatures suggest they are produced by a non-canonical biogenesis pathway. Our data suggest that svRNAs may play a role in SARS-CoV-2 propagation and antagonization of these svRNAs has potential for use as a therapeutic target.
Project description:SARS-CoV-2 is a coronavirus responsible for the COVID-19 pandemic. Although the SARS-CoV-2 trascriptome was reported recently, its coding capacity and the relative production of different viral proteins remained unclear. Utilizing a suit of ribosome profiling techniques, we present a high resolution map of the SARS-CoV-2 coding regions.
Project description:The COVID-19 pandemic has claimed the lives of more than one million people worldwide. The causative agent, SARS-CoV-2, is a member of the Coronaviridae family, which are viruses that cause respiratory infections of varying severity. The cellular host factors and pathways co-opted by SARS- CoV-2 and other coronaviruses in the execution of their life cycles remain ill-defined. To develop an extensive compendium of host factors required for infection by SARS-CoV-2 and three seasonal coronaviruses (HCoV-OC43, HCoV-NL63, and HCoV-229E), we performed parallel genome-scale CRISPR knockout screens. These screens uncovered multiple host factors and pathways with pan- coronavirus and virus-specific functional roles, including major dependency on glycosaminoglycan biosynthesis, SREBP signaling, BMP signaling, and glycosylphosphatidylinositol biosynthesis, as well as a requirement for several poorly characterized proteins. We identified an absolute requirement for the VTT-domain containing protein TMEM41B for infection by SARS-CoV-2 and three seasonal coronaviruses. This human Coronaviridae host factor compendium represents a rich resource to develop new therapeutic strategies for acute COVID-19 and potential future coronavirus spillover events.