Viral and Host Small RNA Response to SARS-CoV-2 Infection
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ABSTRACT: HEK293T cells overexpressing hACE2 were infected by SARS-CoV-2 (WA1) and small RNA-seq was performed to profile small RNAs in response to SARS-COV-2 infection
Project description:HEK293T stable express hACE2 was infected by SARS-CoV-2 (WA1) and RNA-seq was performed to profile host gene expression in response to SARS-COV-2 infection
Project description:In our study, we found that SARS-CoV-2-S pseudovirions infection induced high levels of autophagy and apoptosis in infected cells. To further investigate the underlying regualtion of SARS-CoV-2-S pseudovirions infection in infected cells, ACE2-expressing HEK293T-hACE2 and Vero E6 cells were treated with Mock or SARS-CoV-2-S pseudovirions for RNA-Seq analysis to exame the expression of autophagy- and apoptosis-related genes. Our results indicate that the majority of autophagy- and apoptosis-promoting genes were significantly increased in SARS-CoV-2-S pseudovirions treated HEK293T-hACE2 and Vero E6 cells. In contrast, the subset of autophagy- and apoptosis-suppressing genes was significantly decreased in SARS-CoV-2-S pseudovirions-treated HEK293T-hACE2 and Vero E6 cells than Mock-treated HEK293T-hACE2 and Vero E6 cells. Meanwhile, SARS-CoV-2-S pseudovirions infection enhanced the expression of pro-inflammatory cytokines in infected cells.
Project description:hACE2 transgenic mice were infected with the original SARS-CoV-2 strain (B.1) and the Beta (B.1.351) variant. Lung and spleen samples were collected 1 day post infection (DPI), 3 DPI and 5 DPI, and mRNA was sequenced.
Project description:Very few live attenuated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are currently in pre-clinical or clinical development. We rationally attenuated SARS-CoV-2 (isolate WA1/2020) by removing the polybasic cleavage site within the spike protein and the open reading frames (ORFs) 6-8, and by introducing a pair of mutations into the non-structural protein 1 (Nsp1). The derived virus (WA1-DPRRA-ORF6-8-Nsp1K164A/H165A) became severely attenuated in both the K18-human ACE2 (hACE2) transgenic mice and in Syrian hamsters. Transcriptomic profiling of nasal turbinates and lung tissues of infected Syrian hamsters confirmed that WA1-DPRRA-ORF6-8-Nsp1K164A/H165A attenuated the upregulation of proinflammatory pathways. A single intranasal immunization of just 100 PFU of the WA1-DPRRA-ORF6-8-Nsp1K164A/H165A elicited binding and neutralizing antibody responses in Syrian hamsters and completely protected against SARS-CoV-2-induced weight loss and pneumonia. These data demonstrate the feasibility of rational attenuation of SARS-CoV-2. WA1-DPRRA-ORF6-8-Nsp1K164A/H165A represents a promising live attenuated vaccine candidate.
Project description:A recombinant SARS-CoV lacking the envelope (E) protein is attenuated in vivo. Here we report that E protein PDZ-binding motif (PBM), a domain involved in protein-protein interactions, is a major virulence determinant in vivo. Elimination of SARS-CoV E protein PBM by using reverse genetics led to attenuated viruses (SARS-CoV-mutPBM) and to a reduction in the deleterious exacerbate immune response triggered during infection with the parental virus (SARS-CoV-wt). Cellular protein syntenin bound E protein PBM during SARS-CoV infection. Syntenin activates p38 MAPK leading to overexpression of inflammatory cytokines, and we have shown that active p38 MAPK was reduced in lungs of mice infected with SARS-CoVs lacking E protein PBM (SARS-CoV-mutPBM) as compared with the parental virus (SARS-CoV-wt), leading to a decreased expression of inflammatory cytokines and to viral attenuation. Therefore, E protein PBM is a virulence factor that activates pathogenic immune response most likely by using syntenin as a mediator of p38 MAPK induced inflammation. Three biological replicates were independently hybridized (one channel per slide) for each sample type (SARS-CoV-wt, SARS-CoV-mutPBM, Mock). Slides were Sure Print G3 Agilent 8x60K Mouse (G4852A-028005)
Project description:SARS-CoV and SARS-CoV-2, the causative agents of severe acute respiratory syndrome (SARS) and coronavirus disease 2019 (COVID-19), are genetically related positive-sense RNA viruses that may cause similar pathophysiology. Despite host could activate interferon responses upon coronaviral infection to suppress virus replication, both SARS-CoV and SARS-CoV-2 have evolved strategies to inhibit interferon response. Here, we constructed SARS-CoV and SARS-CoV-2 N proteins expressing cell lines (HEK293T-N and HEK293T-2N) and performed RNA sequencing analysis, showing that both SARS-CoV-2 and SARS-CoV N proteins could inhibit expression of early growth response gene 1 (EGR1) to suppress interferon response. Moreover, EGR1 could degrade N proteins of SARS-CoV and SARS-CoV-2 in a lysosome-dependent manner, and inhibit viral replication of SARS-CoV-2. Our findings revealed the important role of EGR1 in host innate immune response against SARS-CoV and SARS-CoV-2, which would contribute to understanding the pathogenesis of human coronaviruses and development of antiviral therapies. In addition, we demonstrated that both N proteins could upregulate expression of nervous development-related genes, which may be associated with the neurological symptoms of COVID-19 and SARS patients.
Project description:The COVID-19 pandemic is an infectious disease caused by SARS-CoV-2. The first step of SARS-CoV-2 infection is the recognition of angiotensin-converting enzyme 2 (hACE2) receptors by the receptor-binding domain (RBD) of the viral spike (S) glycoprotein. Although the molecular and structural bases of the SARS-CoV-2-RBD/hACE2 interaction have been thoroughly investigated in vitro, the relationship between hACE2 expression and in vivo infection is less understood. Here, we developed an efficient SARS-CoV-2-RBD binding assay suitable for super resolution microscopy and simultaneous hACE2 immunodetection and mapped the correlation between hACE2 receptor abundance and SARS-CoV-2-RBD binding, both in vitro and in human lung biopsies. Next, we explored the specific proteome of SARS-CoV-2-RBD/hACE2 through a comparative mass spectrometry approach. We found that only a minority of hACE2 positive spots are actually SARS-CoV-2-RBD binding sites, and that the relationship between SARS-CoV-2-RBD binding and hACE2 presence is variable, suggesting the existence of additional factors. Indeed, we found several interactors that are involved in receptor localization and viral entry and characterized one of them: SLC1A5, an amino acid transporter. High-resolution receptor-binding studies showed that co-expression of membrane-bound SLC1A5 with hACE2 predicted SARS-CoV-2 binding and entry better than hACE2 expression alone. Accordingly, SLC1A5 depletion reduces SARS-CoV-2 binding and entry. Notably, the Omicron variant is more efficient in binding hACE2 sites, but equally sensitive to SLC1A5 downregulation. We propose a method for mapping functional SARS-CoV-2 receptors in vivo. We confirm the existence of hACE2 co-factors that may contribute to differential sensitivity of cells to infection.
Project description:Severe acute respiratory syndrome coronavirus (SARS-CoV) causes lethal disease in humans, with viral E protein promoting the exacerbated inflammatory response. By deep sequencing RNAs from the lungs of infected mice, we have addressed the relevance of small, non-coding RNAs in SARS-CoV pathology. Host microRNAs (miRNAs) expressed during infection by a virulent virus encoding the E protein were significantly enriched for cytokine-mediated inflammatory pathways when compared with attenuated SARS-CoV-∆E, suggesting contribution of miRNAs to E protein-induced inflammation. The discovery of three 18-22 nt small viral RNAs (svRNAs) derived from the nsp3 and N genomic regions of SARS-CoV in mouse lung and cell cultures is also described. Depletion of these svRNAs significantly reduced viral titers and genomic RNA levels, indicating their positive contribution to virus growth. Remarkably, svRNA-N antagomirs significantly reduced in vivo lung pathology and pro-inflammatory cytokine expression, indicating that svRNAs contribute to SARS-CoV pathogenesis and highlighting the potential of these antagomirs as antivirals.
Project description:We profiled vRNA-host protein interactomes for three RNA virus pathogens (SARS-CoV-2, Zika, and Ebola viruses) using ChIRP-MS. Comparative interactome analyses discovered both common and virus-specific host responses and vRNA-associated proteins that variously promote or restrict viral infection. In particular, SARS-CoV-2 binds and hijacks the host factor IGF2BP1 to stabilize vRNA and augment translation. Our interactome-informed drug repurposing efforts identified several FDA-approved drugs (e.g., Cepharanthine) as broad-spectrum antivirals in cells and hACE2 mice. A co-treatment comprising Cepharanthine and Trifluoperazine was highly potent against the newly emerged SARS-CoV-2 B.1.351 variant. Thus, our study illustrates the scientific and medical discovery utility of adopting a comparative vRNA-host protein interactome perspective.