Project description:The Angiotensin-converting enzyme 2 (ACE2) receptor is the central entry point for SARS-Cov2. Several SAR-Cov2 substrains have developed mutations in their spike protein to maximize their use of ACE2, e.g. to strengthen ACE2 binding for increased uptake or adapt to specific amino acid properties of ACE2 to cross the species barrier. But little is known about the effect of host regulators on ACE2 and subsequently their impact on SARS-Cov2 infection. Here we identify the E3 ligase MDM2 as a ACE2 modulator. The knockout of MDM2 induced a strong pro-viral effect specific for SARS-Cov2 and we could see the increase of ACE2 levels. This effect is likely dependent on the ubiquitination site Lysine 788, which MDM2 uses to induce proteasomal degradation of ACE2. Substituting this amino acid led to increased ACE2 levels and increased SARS-CoV2 infection facilitated by enhanced SARS-Cov2 uptake.
Project description:Here, A549 cells expressing the ACE2 receptor were infected with SARS-CoV2, and pCHi-C was performed at 0 (mock), 8 and 24 hours post-infection. This repository provides the raw pCHi-C sequence reads and downstream processed CHiCAGO data (Rds files).
Project description:To determine the effects of SARS-CoV-2 infection on the host transcriptional profile, total RNA was isolated from infected cells and analyzed by microarray. For these studies, we took into account that the SARS-CoV-2 replication cycle in cell culture is 6-16 h, followed by death of infected cells 28. Therefore, to evaluate the direct effects of virus infection and avoid the analysis of secondary infection events or cell death effects, we did not extend our analysis beyond 24 h post infection. Analysis of significantly differentially expressed genes showed substantial transcriptomic changes in Calu-3 cells with a total of 3215 differentially expressed genes (FDR< 10%).
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:Purpose: The goals of this study are to monitor the evolution pattern of SARS-CoV2 in depending host cells by viral transcriptome sequencing analysis of Vero, A549, Caco2, and HRT18 cells infected with SARS-CoV2. Methods: SARS-CoV-2 isolate was passaged 4 time on Vero cells and used to extract RNA for the high-throughput sequencing. The 8×104 PFU of SARS-CoV2 stocks passaged on vero cells were inoculated to the monolayer of A549, CaCO2, and HRT-18 cell lines in 75T flask for 1hour at 37℃ in a 5% CO2 incubator with gentle shaking of 15 minutes interval. After that, the infected cells were washed two times with DPBS and incubated with the fresh maintenance medium for 3 days. The virus inoculation was performed in triplicate for each cell lines. In case of the first passage, the infected cell pellets were resuspended to 250µl with fresh medium, to extract RNA for the high-throughput sequencing. The cultured cell supernatant of the virus-infected A549, CaCO2, and HRT18 cells was centrifuged at 3,000g for 10min to use for the next passage, and stored at -80℃. The serial passage of SARS-CoV-2 on A549, CaCO2, and HRT18 cell lines were continued to passage 12 and the cultured cell supernatant of the infected cells in passage 12 was centrifuged at 3,000g for 10 min, and used to extract RNA for the high-throughput sequencing. The RNA samples were sequenced with illumine TruSeq Strand Total RNA LT kit and illumine NovaSeq6000 plaform form Macrogen, Inc (Seoul, Korea) for high throughput sequencing. The raw reads were trimmed with BBDuk and mapped the isolate SARS-CoV-2/human/KOR/KCDC03-NCCP43326/2020 (Genebank accession number. MW466791) with Bowtie 2 using Geneious program 2021.2.2 Result: Using SNP analysis workflow, our result showed the sequence variations pattern of SARS-CoV2 depending on host cell (A549, CaCO2, and HRT18 cell lines) and it was confirmed that a relatively large number of SNPs were commonly observed in spike protein. Some SNPs affect amino acid changes, and a common pattern of amino acid changes was observed the genomic sequence of SARS-CoV2 passaged in A549, CaCO2 and HRT18 cells. Conclusion: In this study, we tried to monitor the SARS-CoV-2 (GenBank accession No. MW466791 in 2020, Korea) evolution pattern in different host cells using high throughput sequencing analysis, and compare the selected mutations by each host cells with natural mutations found in currently circulating SARS-CoV-2 variants.
Project description:We studied miRNAs and their gene targets affecting SARS-CoV-2 pathogenesis in CF airway epithelial cell models in response to TGF-β1. Small RNAseq in CF human bronchial epithelial cell line treated with TGF-β1 and miRNA profiling characterized TGF-β1 effects on the SARS-CoV-2 pathogenesis pathways. Among the effectors, we identified and validated two miRNAs targeting ACE2 mRNA using different CF and non-CF human bronchial epithelial cell models. We have shown that TGF-β1 inhibits ACE2 expression by miR-136-3p and miR-369-5p. ACE2 levels were higher in cells expressing F508del-CFTR, compared to wild-type(WT)-CFTR and TGF-β1 inhibited ACE2 in both cell types. The ACE2 protein levels were still higher in CF, compared to non-CF cells after TGF-β1 treatment. TGF-β1 prevented the functional rescue of F508del-CFTR by ETI in primary human bronchial epithelial cells while ETI did not prevent the TGF-β1 inhibition of ACE2 protein. Finally, TGF-β1 reduced binding of ACE2 to the recombinant monomeric spike RBD. Our results may help to explain, at least in part, the role of TGF-β1 on the SARS-CoV-2 entry via ACE2 in the CF and non-CF airway.